cmd/compress/compress.c

	compress.c revision 3d63ea05cb8474d8036d3588cf8299306a994b8c
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


/*
 * Copyright (c) 1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Compress - data compression program
 */
#define min(a, b)   ((a > b) ? b : a)

/*
 * machine variants which require cc -Dmachine:  pdp11, z8000, pcxt
 */

/*
 * Set USERMEM to the maximum amount of physical user memory available
 * in bytes.  USERMEM is used to determine the maximum BITS that can be used
 * for compression.
 *
 * SACREDMEM is the amount of physical memory saved for others; compress
 * will hog the rest.
 */
#ifndef SACREDMEM
#define SACREDMEM   0
#endif

#ifndef USERMEM
#define USERMEM     450000  /* default user memory */
#endif

#ifdef USERMEM
#if USERMEM >= (433484+SACREDMEM)
#define PBITS   16
#else
#if USERMEM >= (229600+SACREDMEM)
#define PBITS   15
#else
#if USERMEM >= (127536+SACREDMEM)
#define PBITS   14
#else
#if USERMEM >= (73464+SACREDMEM)
#define PBITS   13
#else
#define PBITS   12
#endif
#endif
#endif
#endif
#undef USERMEM
#endif /* USERMEM */

#ifdef PBITS        /* Preferred BITS for this memory size */
#ifndef BITS
#define BITS PBITS
#endif /* BITS */
#endif /* PBITS */

#if BITS == 16
#define HSIZE   69001       /* 95% occupancy */
#endif
#if BITS == 15
#define HSIZE   35023       /* 94% occupancy */
#endif
#if BITS == 14
#define HSIZE   18013       /* 91% occupancy */
#endif
#if BITS == 13
#define HSIZE   9001        /* 91% occupancy */
#endif
#if BITS <= 12
#define HSIZE   5003        /* 80% occupancy */
#endif

#define OUTSTACKSIZE    (2<<BITS)

/*
 * a code_int must be able to hold 2**BITS values of type int, and also -1
 */
#if BITS > 15
typedef long int    code_int;
#else
typedef int     code_int;
#endif

typedef long int    count_int;
typedef long long   count_long;

typedef unsigned char   char_type;

static char_type magic_header[] = { "\037\235" }; /* 1F 9D */

/* Defines for third byte of header */
#define BIT_MASK    0x1f
#define BLOCK_MASK  0x80
/*
 * Masks 0x40 and 0x20 are free.  I think 0x20 should mean that there is
 * a fourth header byte(for expansion).
 */
#define INIT_BITS 9         /* initial number of bits/code */

/*
 * compress.c - File compression ala IEEE Computer, June 1984.
 */
static char rcs_ident[] =
    "$Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $";

#include <stdio.h>
#include <ctype.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/param.h>
#include <stdlib.h>         /* XCU4 */
#include <limits.h>
#include <libintl.h>
#include <locale.h>
#include <langinfo.h>
#include <string.h>
#include <sys/acl.h>
#include <utime.h>
#include <libgen.h>
#include <setjmp.h>
#include <strings.h>
#include <fcntl.h>
#include <dirent.h>
#include <aclutils.h>
#include <errno.h>
#include "getresponse.h"

static int n_bits;          /* number of bits/code */
static int maxbits = BITS;  /* user settable max # bits/code */
static code_int maxcode;    /* maximum code, given n_bits */
            /* should NEVER generate this code */
static code_int maxmaxcode = 1 << BITS;
#define MAXCODE(n_bits) ((1 << (n_bits)) - 1)

static count_int htab [OUTSTACKSIZE];
static unsigned short codetab [OUTSTACKSIZE];

#define htabof(i)   htab[i]
#define codetabof(i)    codetab[i]
static code_int hsize = HSIZE; /* for dynamic table sizing */
static off_t    fsize;  /* file size of input file */

/*
 * To save much memory, we overlay the table used by compress() with those
 * used by decompress().  The tab_prefix table is the same size and type
 * as the codetab.  The tab_suffix table needs 2**BITS characters.  We
 * get this from the beginning of htab.  The output stack uses the rest
 * of htab, and contains characters.  There is plenty of room for any
 * possible stack (stack used to be 8000 characters).
 */

#define tab_prefixof(i)     codetabof(i)
#define tab_suffixof(i)     ((char_type *)(htab))[i]
#define de_stack        ((char_type *)&tab_suffixof(1<<BITS))
#define stack_max       ((char_type *)&tab_suffixof(OUTSTACKSIZE))

static code_int free_ent = 0; /* first unused entry */
static int newline_needed = 0;
static int didnt_shrink = 0;
static int perm_stat = 0;   /* permanent status */

static code_int getcode();

    /* Use a 3-byte magic number header, unless old file */
static int nomagic = 0;
    /* Write output on stdout, suppress messages */
static int zcat_flg = 0;    /* use stdout on all files */
static int zcat_cmd = 0;    /* zcat cmd */
static int use_stdout = 0;  /* set for each file processed */
    /* Don't unlink output file on interrupt */
static int precious = 1;
static int quiet = 1;   /* don't tell me about compression */

/*
 * block compression parameters -- after all codes are used up,
 * and compression rate changes, start over.
 */
static int block_compress = BLOCK_MASK;
static int clear_flg = 0;
static long int ratio = 0;
#define CHECK_GAP 10000 /* ratio check interval */
static count_long checkpoint = CHECK_GAP;
/*
 * the next two codes should not be changed lightly, as they must not
 * lie within the contiguous general code space.
 */
#define FIRST   257 /* first free entry */
#define CLEAR   256 /* table clear output code */

static int force = 0;
static char ofname [MAXPATHLEN];

static int Vflg = 0;
static int vflg = 0;
static int qflg = 0;
static int bflg = 0;
static int Fflg = 0;
static int dflg = 0;
static int cflg = 0;
static int Cflg = 0;

#ifdef DEBUG
int verbose = 0;
int debug = 0;
#endif /* DEBUG */

static void (*oldint)();
static int bgnd_flag;

static int do_decomp = 0;

static char *progname;
static char *optstr;
/*
 * Fix lint errors
 */

static char *local_basename(char *);

static int  addDotZ(char *, size_t);

static void Usage(void);
static void cl_block(count_long);
static void cl_hash(count_int);
static void compress(void);
static void copystat(char *, struct stat *, char *);
static void decompress(void);
static void ioerror(void);
static void onintr();
static void oops();
static void output(code_int);
static void prratio(FILE *, count_long, count_long);
static void version(void);
static int mv_xattrs(char *, char *, int);

#ifdef DEBUG
static int in_stack(int, int);
static void dump_tab(void);
static void printcodes(void);
#endif

/* For error-handling */

static jmp_buf env;

/* For input and ouput */

static FILE *inp;       /* the current input file */
static FILE *infile;        /* disk-based input stream */
static FILE *outp;      /* current output file */
static FILE *outfile;       /* disk-based output stream */

/* For output() */

static char buf[BITS];

static char_type lmask[9] =
    {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00};
static char_type rmask[9] =
    {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};

/* For compress () */

static int offset;
static count_long bytes_out;    /* length of compressed output */
    /* # of codes output (for debugging) */

/* For dump_tab() */

#define STACK_SIZE  15000
#ifdef DEBUG
code_int sorttab[1<<BITS];  /* sorted pointers into htab */
#endif

/*
 * *************************************************************
 * TAG( main )
 *
 * Algorithm from "A Technique for High Performance Data Compression",
 * Terry A. Welch, IEEE Computer Vol 17, No 6 (June 1984), pp 8-19.
 *
 * Usage: compress [-dfvc] [-b bits] [file ...]
 * Inputs:
 *  -d:     If given, decompression is done instead.
 *
 *  -c:     Write output on stdout, don't remove original.
 *
 *  -b:     Parameter limits the max number of bits/code.
 *
 *  -f:     Forces output file to be generated, even if one already
 *          exists, and even if no space is saved by compressing.
 *          If -f is not used, the user will be prompted if stdin is
 *          a tty, otherwise, the output file will not be overwritten.
 *
 *  -v:     Write compression statistics
 *
 *  file ...:   Files to be compressed.  If none specified, stdin
 *          is used.
 * Outputs:
 *  file.Z:     Compressed form of file with same mode, owner, and utimes
 *  or stdout   (if stdin used as input)
 *
 * Assumptions:
 * When filenames are given, replaces with the compressed version
 * (.Z suffix) only if the file decreases in size.
 * Algorithm:
 * Modified Lempel-Ziv method (LZW).  Basically finds common
 * substrings and replaces them with a variable size code.  This is
 * deterministic, and can be done on the fly.  Thus, the decompression
 * procedure needs no input table, but tracks the way the table was built.
 */

int
main(int argc, char *argv[])
{
    int overwrite = 0;  /* Do not overwrite unless given -f flag */
    char tempname[MAXPATHLEN];
    char line[LINE_MAX];
    char **filelist, **fileptr;
    char *cp;
    struct stat statbuf;
    struct stat ostatbuf;
    int ch;             /* XCU4 */
    char    *p;
    extern int optind, optopt;
    extern char *optarg;
    int dash_count = 0;     /* times "-" is on cmdline */

    /* XCU4 changes */
    (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)   /* Should be defined by cc -D */
#define TEXT_DOMAIN "SYS_TEST"  /* Use this only if it weren't */
#endif
    (void) textdomain(TEXT_DOMAIN);

    if (init_yes() < 0) {
        (void) fprintf(stderr, gettext(ERR_MSG_INIT_YES),
            strerror(errno));
        exit(1);
    }

    /* This bg check only works for sh. */
    if ((oldint = signal(SIGINT, SIG_IGN)) != SIG_IGN) {
        (void) signal(SIGINT, onintr);
        (void) signal(SIGSEGV, oops);
    }
    bgnd_flag = oldint != SIG_DFL;

    /* Allocate room for argv + "-" (if stdin needs to be added) */

    filelist = fileptr = (char **)(malloc((argc + 1) * sizeof (*argv)));
    *filelist = NULL;

    if ((cp = rindex(argv[0], '/')) != 0) {
        cp++;
    } else {
        cp = argv[0];
    }

    if (strcmp(cp, "uncompress") == 0) {
        do_decomp = 1;
    } else if (strcmp(cp, "zcat") == 0) {
        do_decomp = 1;
        zcat_cmd = zcat_flg = 1;
    }

    progname = local_basename(argv[0]);

    /*
     * Argument Processing
     * All flags are optional.
     * -D = > debug
     * -V = > print Version; debug verbose
     * -d = > do_decomp
     * -v = > unquiet
     * -f = > force overwrite of output file
     * -n = > no header: useful to uncompress old files
     * -b     maxbits => maxbits.  If -b is specified,
     *    then maxbits MUST be given also.
     * -c = > cat all output to stdout
     * -C = > generate output compatible with compress 2.0.
     * if a string is left, must be an input filename.
     */
#ifdef DEBUG
    optstr = "b:cCdDfFnqvV";
#else
    optstr = "b:cCdfFnqvV";
#endif

    while ((ch = getopt(argc, argv, optstr)) != EOF) {
        /* Process all flags in this arg */
        switch (ch) {
#ifdef DEBUG
            case 'D':
                debug = 1;
                break;
            case 'V':
                verbose = 1;
                version();
                break;
#else
            case 'V':
                version();
                Vflg++;
                break;
#endif /* DEBUG */
            case 'v':
                quiet = 0;
                vflg++;
                break;
            case 'd':
                do_decomp = 1;
                dflg++;
                break;
            case 'f':
            case 'F':
                Fflg++;
                overwrite = 1;
                force = 1;
                break;
            case 'n':
                nomagic = 1;
                break;
            case 'C':
                Cflg++;
                block_compress = 0;
                break;
            case 'b':
                bflg++;
                p = optarg;
                if (!p) {
                    (void) fprintf(stderr, gettext(
                        "Missing maxbits\n"));
                    Usage();
                    exit(1);
                }
                maxbits = strtoul(optarg, &p, 10);
                if (*p) {
                    (void) fprintf(stderr, gettext(
                        "Missing maxbits\n"));
                    Usage();
                    exit(1);
                }
                break;

            case 'c':
                cflg++;
                zcat_flg = 1;
                break;
            case 'q':
                qflg++;
                quiet = 1;
                break;
            default:
                (void) fprintf(stderr, gettext(
                    "Unknown flag: '%c'\n"), optopt);
                Usage();
                exit(1);
        }
    } /* while */

    /*
     * Validate zcat syntax
     */

    if (zcat_cmd && (Fflg | Cflg | cflg |
        bflg | qflg | dflg | nomagic)) {
        (void) fprintf(stderr, gettext(
            "Invalid Option\n"));
        Usage();
        exit(1);
    }

    /*
     * Process the file list
     */

    for (; optind < argc; optind++) {
        if (strcmp(argv[optind], "-") == 0) {
            dash_count++;
        }

        *fileptr++ = argv[optind];  /* Build input file list */
        *fileptr = NULL;
    }

    if (dash_count > 1) {
        (void) fprintf(stderr,
            gettext("%s may only appear once in the file"
            " list\n"), "\"-\"");
        exit(1);
    }

    if (fileptr - filelist == 0) {
        *fileptr++ = "-";
        *fileptr = NULL;
    }

    if (fileptr - filelist > 1 && cflg && !do_decomp) {
        (void) fprintf(stderr,
            gettext("compress: only one file may be compressed"
            " to stdout\n"));
        exit(1);
    }

    if (maxbits < INIT_BITS)
        maxbits = INIT_BITS;
    if (maxbits > BITS)
        maxbits = BITS;
    maxmaxcode = 1 << maxbits;

    /* Need to open something to close with freopen later */

    if ((infile = fopen("/dev/null", "r")) == NULL) {
        (void) fprintf(stderr, gettext("Error opening /dev/null for "
            "input\n"));
        exit(1);
    }

    if ((outfile = fopen("/dev/null", "w")) == NULL) {
        (void) fprintf(stderr, gettext("Error opening /dev/null for "
            "output\n"));
        exit(1);
    }

    for (fileptr = filelist; *fileptr; fileptr++) {
        int jmpval = 0;
        didnt_shrink = 0;
        newline_needed = 0;

        if (do_decomp) {
            /* DECOMPRESSION */

            if (strcmp(*fileptr, "-") == 0) {
                /* process stdin */
                inp = stdin;
                outp = stdout;
                use_stdout = 1;
                *fileptr = "stdin"; /* for error messages */
            } else {
                /* process the named file */

                inp = infile;
                outp = outfile;
                use_stdout = 0;

                if (zcat_flg) {
                    use_stdout = 1;
                    outp = stdout;
                }

                /* Check for .Z suffix */

                if (strcmp(*fileptr +
                    strlen(*fileptr) - 2, ".Z") != 0) {
                    /* No .Z: tack one on */

                    if (strlcpy(tempname, *fileptr,
                        sizeof (tempname)) >=
                        sizeof (tempname)) {
                        (void) fprintf(stderr,
                            gettext("%s: filename "
                            "too long\n"),
                            *fileptr);
                        perm_stat = 1;
                        continue;
                    }

                    if (addDotZ(tempname,
                        sizeof (tempname)) < 0) {
                        perm_stat = 1;
                        continue;
                    }

                    *fileptr = tempname;
                }

                /* Open input file */

                if (stat(*fileptr, &statbuf) < 0) {
                    perror(*fileptr);
                    perm_stat = 1;
                    continue;
                }

                if ((freopen(*fileptr, "r", inp)) == NULL) {
                    perror(*fileptr);
                    perm_stat = 1;
                    continue;
                }
            }

            /* Check the magic number */

            if (nomagic == 0) {
                if ((getc(inp) !=
                    (magic_header[0] & 0xFF)) ||
                    (getc(inp) !=
                    (magic_header[1] & 0xFF))) {
                    (void) fprintf(stderr, gettext(
                        "%s: not in compressed "
                        "format\n"),
                        *fileptr);
                    perm_stat = 1;
                    continue;
                }

                /* set -b from file */
                if ((maxbits = getc(inp)) == EOF &&
                    ferror(inp)) {
                    perror(*fileptr);
                    perm_stat = 1;
                    continue;
                }

                block_compress = maxbits & BLOCK_MASK;
                maxbits &= BIT_MASK;
                maxmaxcode = 1 << maxbits;

                if (maxbits > BITS) {
                    (void) fprintf(stderr,
                        gettext("%s: compressed "
                        "with %d bits, "
                        "can only handle"
                        " %d bits\n"),
                        *fileptr, maxbits, BITS);
                    perm_stat = 1;
                    continue;
                }
            }

            if (!use_stdout) {
                /* Generate output filename */

                if (strlcpy(ofname, *fileptr,
                    sizeof (ofname)) >=
                    sizeof (ofname)) {
                    (void) fprintf(stderr,
                        gettext("%s: filename "
                        "too long\n"),
                        *fileptr);
                    perm_stat = 1;
                    continue;
                }

                /* Strip off .Z */

                ofname[strlen(*fileptr) - 2] = '\0';
            }
        } else {
            /* COMPRESSION */

            if (strcmp(*fileptr, "-") == 0) {
                /* process stdin */
                inp = stdin;
                outp = stdout;
                use_stdout = 1;
                *fileptr = "stdin"; /* for error messages */

                /* Use the largest possible hash table */
                hsize =  HSIZE;
            } else {
                /* process the named file */

                inp = infile;
                outp = outfile;
                use_stdout = 0;

                if (zcat_flg) {
                    use_stdout = 1;
                    outp = stdout;
                }

                if (strcmp(*fileptr +
                    strlen(*fileptr) - 2, ".Z") == 0) {
                    (void) fprintf(stderr, gettext(
                        "%s: already has .Z "
                        "suffix -- no change\n"),
                        *fileptr);
                    perm_stat = 1;
                    continue;
                }
                /* Open input file */

                if (stat(*fileptr, &statbuf) < 0) {
                    perror(*fileptr);
                    perm_stat = 1;
                    continue;
                }

                if ((freopen(*fileptr, "r", inp)) == NULL) {
                    perror(*fileptr);
                    perm_stat = 1;
                    continue;
                }

                fsize = (off_t)statbuf.st_size;

                /*
                 * tune hash table size for small
                 * files -- ad hoc,
                 * but the sizes match earlier #defines, which
                 * serve as upper bounds on the number of
                 * output codes.
                 */
                hsize = HSIZE;
                if (fsize < (1 << 12))
                    hsize = min(5003, HSIZE);
                else if (fsize < (1 << 13))
                    hsize = min(9001, HSIZE);
                else if (fsize < (1 << 14))
                    hsize = min(18013, HSIZE);
                else if (fsize < (1 << 15))
                    hsize = min(35023, HSIZE);
                else if (fsize < 47000)
                    hsize = min(50021, HSIZE);

                if (!use_stdout) {
                    /* Generate output filename */

                    if (strlcpy(ofname, *fileptr,
                        sizeof (ofname)) >=
                        sizeof (ofname)) {
                        (void) fprintf(stderr,
                            gettext("%s: filename "
                            "too long\n"),
                            *fileptr);
                        perm_stat = 1;
                        continue;
                    }

                    if (addDotZ(ofname,
                        sizeof (ofname)) < 0) {
                        perm_stat = 1;
                        continue;
                    }
                }
            }
        }   /* if (do_decomp) */

        /* Check for overwrite of existing file */

        if (!overwrite && !use_stdout) {
            if (stat(ofname, &ostatbuf) == 0) {
                (void) fprintf(stderr, gettext(
                    "%s already exists;"), ofname);
                if (bgnd_flag == 0 && isatty(2)) {
                    int cin;

                    (void) fprintf(stderr, gettext(
                        " do you wish to overwr"
                        "ite %s (%s or %s)? "),
                        ofname, yesstr, nostr);
                    (void) fflush(stderr);
                    for (cin = 0; cin < LINE_MAX; cin++)
                        line[cin] = 0;
                    (void) read(2, line, LINE_MAX);

                    if (yes_check(line) == 0) {
                        (void) fprintf(stderr,
                            gettext(
                            "\tnot overwri"
                            "tten\n"));
                        continue;
                    }
                } else {
                    /*
                     * XPG4: Assertion 1009
                     * Standard input is not
                     * terminal, and no '-f',
                     * and file exists.
                     */

                    (void) fprintf(stderr, gettext(
                        "%s: File exists, -f not"
                        " specified, and ru"
                        "nning in the backgro"
                        "und.\n"), *fileptr);
                    perm_stat = 1;
                    continue;
                }
            }
        }
        if (!use_stdout) {
            if (pathconf(ofname, _PC_XATTR_EXISTS) == 1) {
                (void) unlink(ofname);
            }
            /* Open output file */
            if (freopen(ofname, "w", outp) == NULL) {
                perror(ofname);
                perm_stat = 1;
                continue;
            }
            precious = 0;
            if (!quiet) {
                (void) fprintf(stderr, "%s: ",
                    *fileptr);
                newline_needed = 1;
            }
        } else if (!quiet && !do_decomp) {
            (void) fprintf(stderr, "%s: ",
                *fileptr);
                newline_needed = 1;
        }

        /* Actually do the compression/decompression */

        if ((jmpval = setjmp(env)) == 0) {
            /* We'll see how things go */
#ifndef DEBUG
            if (do_decomp == 0)  {
                compress();
            } else {
                decompress();
            }
#else
            if (do_decomp == 0)  {
                compress();
            } else if (debug == 0)  {
                decompress();
            } else {
                printcodes();
            }

            if (verbose) {
                dump_tab();
            }
#endif
        } else {
            /*
             * Things went badly - clean up and go on.
             * jmpval's values break down as follows:
             *   1 == message determined by ferror() values.
             *   2 == input problem message needed.
             *   3 == output problem message needed.
             */

            if (ferror(inp) || jmpval == 2) {
                if (do_decomp) {
                    (void) fprintf(stderr, gettext(
                        "uncompress: %s: corrupt"
                        " input\n"), *fileptr);
                } else {
                    perror(*fileptr);
                }
            }

            if (ferror(outp) || jmpval == 3) {
                /* handle output errors */

                if (use_stdout) {
                    perror("");
                } else {
                    perror(ofname);
                }
            }

            if (ofname[0] != '\0') {
                if (unlink(ofname) < 0)  {
                    perror(ofname);
                }

                ofname[0] = '\0';
            }

            perm_stat = 1;
            continue;
        }

        /* Things went well */

        if (!use_stdout) {
                /* Copy stats */
            copystat(*fileptr, &statbuf, ofname);
            precious = 1;
            if (newline_needed) {
                (void) putc('\n', stderr);
            }
            /*
             * Print the info. for unchanged file
             * when no -v
             */

            if (didnt_shrink) {
                if (!force && perm_stat == 0) {
                    if (quiet) {
                        (void) fprintf(stderr, gettext(
                            "%s: -- file "
                            "unchanged\n"),
                            *fileptr);
                    }

                    perm_stat = 2;
                }
            }
        } else {
            if (didnt_shrink && !force && perm_stat == 0) {
                perm_stat = 2;
            }

            if (newline_needed) {
                (void) fprintf(stderr, "\n");
            }
        }
    }   /* for */

    return (perm_stat);
}

static void
cinterr(int hshift)
{
    /* we have exceeded the hash table */
    (void) fprintf(stderr,
        "internal error: hashtable exceeded - hsize = %ld\n", hsize);
    (void) fprintf(stderr, "hshift = %d, %d\n", hshift, (1 << hshift) -1);
    (void) fprintf(stderr, "maxbits = %d\n", maxbits);
    (void) fprintf(stderr, "n_bits = %d\n", n_bits);
    (void) fprintf(stderr, "maxcode = %ld\n", maxcode);
    longjmp(env, 1);
}

static code_int
adjusti(code_int i, code_int hsize_reg)
{
    while (i < 0) {
        i += hsize_reg;
    }

    while (i >= hsize_reg) {
        i -= hsize_reg;
    }
    return (i);
}

/*
 * compress inp to outp
 *
 * Algorithm:  use open addressing double hashing(no chaining) on the
 * prefix code / next character combination.  We do a variant of Knuth's
 * algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
 * secondary probe.  Here, the modular division first probe is gives way
 * to a faster exclusive-or manipulation.  Also do block compression with
 * an adaptive reset, whereby the code table is cleared when the compression
 * ratio decreases, but after the table fills.  The variable-length output
 * codes are re-sized at this point, and a special CLEAR code is generated
 * for the decompressor.  Late addition:  construct the table according to
 * file size for noticeable speed improvement on small files.  Please direct
 * questions about this implementation to ames!jaw.
 */

static void
compress()
{
    long fcode;
    code_int i = 0;
    int c;
    code_int ent;
    int disp;
    code_int hsize_reg;
    int hshift;
    int probecnt;
    count_long in_count;
    uint32_t inchi, inclo;
    int maxbits_reg;
    FILE *fin = inp;
#ifdef DEBUG
    count_long out_count = 0;
#endif

    if (nomagic == 0) {
        if ((putc(magic_header[0], outp) == EOF ||
            putc(magic_header[1], outp) == EOF ||
            putc((char)(maxbits | block_compress),
            outp) == EOF) &&
            ferror(outp)) {
            ioerror();
        }
    }

    offset = 0;
    bytes_out = 3;      /* includes 3-byte header mojo */
    clear_flg = 0;
    ratio = 0;
    in_count = 1;
    inchi = 0;
    inclo = 1;
    checkpoint = CHECK_GAP;
    maxcode = MAXCODE(n_bits = INIT_BITS);
    free_ent = ((block_compress) ? FIRST : 256);

    if ((ent = getc(fin)) == EOF && ferror(fin)) {
        ioerror();
    }

    hshift = 0;

    for (fcode = (long)hsize;  fcode < 65536L; fcode *= 2L)
        hshift++;

    hshift = 8 - hshift;        /* set hash code range bound */

    hsize_reg = hsize;
    maxbits_reg = maxbits;

    cl_hash((count_int) hsize_reg);     /* clear hash table */

    while ((c = getc(fin)) != EOF) {
        if (++inclo == 0)
            inchi++;
        fcode = (long)(((long)c << maxbits_reg) + ent);
        i = ((c << hshift) ^ ent);  /* xor hashing */

        if ((unsigned int)i >= hsize_reg)
            i = adjusti(i, hsize_reg);

        if (htabof(i) == fcode) {
            ent = codetabof(i);
            continue;
        } else if ((long)htabof(i) < 0) {
            /* empty slot */
            goto nomatch;
        }

        /* secondary hash (after G. Knott) */
        disp = hsize_reg - i;

        if (i == 0) {
            disp = 1;
        }

        probecnt = 0;
    probe:
        if (++probecnt > hsize_reg)
            cinterr(hshift);

        if ((i -= disp) < 0) {
            while (i < 0)
                i += hsize_reg;
        }

        if (htabof(i) == fcode) {
            ent = codetabof(i);
            continue;
        }

        if ((long)htabof(i) > 0) {
            goto probe;
        }
    nomatch:
        output((code_int) ent);
#ifdef DEBUG
        out_count++;
#endif
        ent = c;
        if (free_ent < maxmaxcode) {
            codetabof(i) = free_ent++;
            /* code -> hashtable */
            htabof(i) = fcode;
        } else {
            in_count = ((long long)inchi<<32|inclo);
            if ((count_long)in_count >=
                (count_long)checkpoint && block_compress) {
                cl_block(in_count);
            }
        }
    }

    in_count = ((long long)inchi<<32|inclo);

    if (ferror(fin) != 0) {
        ioerror();
    }

    /*
     * Put out the final code.
     */
    output((code_int)ent);
#ifdef DEBUG
    out_count++;
#endif

    output((code_int)-1);

    /*
     * Print out stats on stderr
     */
    if (!quiet) {
#ifdef DEBUG
        (void) fprintf(stderr,
            "%lld chars in, %lld codes (%lld bytes) out, "
            "compression factor: ",
            (count_long)in_count, (count_long)out_count,
            (count_long) bytes_out);
        prratio(stderr, (count_long)in_count,
            (count_long)bytes_out);
        (void) fprintf(stderr, "\n");
        (void) fprintf(stderr, "\tCompression as in compact: ");
        prratio(stderr,
            (count_long)in_count-(count_long)bytes_out,
            (count_long)in_count);
        (void) fprintf(stderr, "\n");
        (void) fprintf(stderr,
            "\tLargest code (of last block) was %d"
            " (%d bits)\n",
            free_ent - 1, n_bits);
#else /* !DEBUG */
        (void) fprintf(stderr, gettext("Compression: "));
        prratio(stderr,
            (count_long)in_count-(count_long)bytes_out,
            (count_long)in_count);
#endif /* DEBUG */
    }
    /* report if no savings */
    if ((count_long)bytes_out > (count_long)in_count) {
        didnt_shrink = 1;
    }
}

/*
 * **************************************************************
 * TAG(output)
 *
 * Output the given code.
 * Inputs:
 *  code:   A n_bits-bit integer.  If == -1, then EOF.  This assumes
 *      that n_bits = < (long)wordsize - 1.
 * Outputs:
 *  Outputs code to the file.
 * Assumptions:
 *  Chars are 8 bits long.
 * Algorithm:
 *  Maintain a BITS character long buffer(so that 8 codes will
 * fit in it exactly).  Use the VAX insv instruction to insert each
 * code in turn.  When the buffer fills up empty it and start over.
 */

static void
output(code_int code)
{
#ifdef DEBUG
    static int col = 0;
#endif /* DEBUG */

    int r_off = offset, bits = n_bits;
    char *bp = buf;

#ifdef DEBUG
    if (verbose)
        (void) fprintf(stderr, "%5d%c", code,
            (col += 6) >= 74 ? (col = 0, '\n') : ' ');
#endif /* DEBUG */
    if (code >= 0) {
        /*
         * byte/bit numbering on the VAX is simulated
         * by the following code
         */
        /*
         * Get to the first byte.
         */
        bp += (r_off >> 3);
        r_off &= 7;
        /*
         * Since code is always >= 8 bits, only need to mask the first
         * hunk on the left.
         */
        *bp = (*bp & rmask[r_off]) | (code << r_off) & lmask[r_off];
        bp++;
        bits -= (8 - r_off);
        code >>= 8 - r_off;
        /*
         * Get any 8 bit parts in the middle (<=1 for up to 16
         * bits).
         */
        if (bits >= 8) {
            *bp++ = code;
            code >>= 8;
            bits -= 8;
        }
        /* Last bits. */
        if (bits)
            *bp = code;
        offset += n_bits;
        if (offset == (n_bits << 3)) {
            bp = buf;
            bits = n_bits;
            bytes_out += bits;
            do {
                if (putc(*bp, outp) == EOF &&
                    ferror(outp)) {
                    ioerror();
                }
                bp++;
            } while (--bits);
            offset = 0;
        }

        /*
         * If the next entry is going to be too big for the code size,
         * then increase it, if possible.
         */
        if (free_ent > maxcode || (clear_flg > 0)) {
            /*
             * Write the whole buffer, because the input
             * side won't discover the size increase until
             * after it has read it.
             */
            if (offset > 0) {
                if (fwrite(buf, 1, n_bits, outp) != n_bits) {
                    longjmp(env, 3);
                }
                bytes_out += n_bits;
            }
            offset = 0;

            if (clear_flg) {
                maxcode = MAXCODE(n_bits = INIT_BITS);
                clear_flg = 0;
            } else {
                n_bits++;
                if (n_bits == maxbits)
                    maxcode = maxmaxcode;
                else
                    maxcode = MAXCODE(n_bits);
            }
#ifdef DEBUG
            if (debug) {
                (void) fprintf(stderr,
                    "\nChange to %d bits\n", n_bits);
                col = 0;
            }
#endif /* DEBUG */
        }
    } else {
        /*
         * At EOF, write the rest of the buffer.
         */
        if (offset > 0) {
            if (fwrite(buf, 1, (offset + 7) / 8, outp) == 0 &&
                ferror(outp)) {
                ioerror();
            }
            bytes_out += (offset + 7) / 8;
        }
        offset = 0;
        (void) fflush(outp);
#ifdef DEBUG
        if (verbose)
            (void) fprintf(stderr, "\n");
#endif /* DEBUG */
        if (ferror(outp))
            ioerror();
    }
}

/*
 * Decompress inp to outp.  This routine adapts to the codes in the
 * file building the "string" table on-the-fly; requiring no table to
 * be stored in the compressed file.  The tables used herein are shared
 * with those of the compress() routine.  See the definitions above.
 */

static void
decompress()
{
    char_type *stackp, *stack_lim;
    int finchar;
    code_int code, oldcode, incode;
    FILE *fout = outp;

    /*
     * As above, initialize the first 256 entries in the table.
     */
    maxcode = MAXCODE(n_bits = INIT_BITS);
    for (code = 255; code >= 0; code--) {
        tab_prefixof(code) = 0;
        tab_suffixof(code) = (char_type)code;
    }
    free_ent = ((block_compress) ? FIRST : 256);

    finchar = oldcode = getcode();
    if (oldcode == -1)  /* EOF already? */
        return;         /* Get out of here */
    /* first code must be 8 bits = char */
    if (putc((char)finchar, outp) == EOF && ferror(outp)) {
        /* Crash if can't write */
        ioerror();
    }
    stackp = de_stack;
    stack_lim = stack_max;

    while ((code = getcode()) > -1) {

        if ((code == CLEAR) && block_compress) {
            for (code = 255; code >= 0; code--)
            tab_prefixof(code) = 0;
            clear_flg = 1;
            free_ent = FIRST - 1;
            if ((code = getcode()) == -1)   /* O, untimely death! */
                break;
        }
        incode = code;
        /*
         * Special case for KwKwK string.
         */
        if (code >= free_ent) {
            if (stackp < stack_lim) {
                *stackp++ = (char_type) finchar;
                code = oldcode;
            } else {
                /* badness */
                longjmp(env, 2);
            }
        }

        /*
         * Generate output characters in reverse order
         */
        while (code >= 256) {
            if (stackp < stack_lim) {
                *stackp++ = tab_suffixof(code);
                code = tab_prefixof(code);
            } else {
                /* badness */
                longjmp(env, 2);
            }
        }
        *stackp++ = finchar = tab_suffixof(code);

        /*
         * And put them out in forward order
         */
        do {
            stackp--;
            (void) putc(*stackp, fout);
        } while (stackp > de_stack);

        if (ferror(fout))
            ioerror();

        /*
         * Generate the new entry.
         */
        if ((code = free_ent) < maxmaxcode) {
            tab_prefixof(code) = (unsigned short) oldcode;
            tab_suffixof(code) = (char_type) finchar;
            free_ent = code+1;
        }
        /*
         * Remember previous code.
         */
        oldcode = incode;
    }
    (void) fflush(outp);
    if (ferror(outp))
        ioerror();
}

/*
 * **************************************************************
 * TAG( getcode )
 *
 * Read one code from the standard input.  If EOF, return -1.
 * Inputs:
 *  inp
 * Outputs:
 *  code or -1 is returned.
 */

code_int
getcode() {
    code_int code;
    static int offset = 0, size = 0;
    static char_type buf[BITS];
    int r_off, bits;
    char_type *bp = buf;

    if (clear_flg > 0 || offset >= size || free_ent > maxcode) {
        /*
         * If the next entry will be too big for the current code
         * size, then we must increase the size.  This implies reading
         * a new buffer full, too.
         */
        if (free_ent > maxcode) {
            n_bits++;
            if (n_bits == maxbits)
                /* won't get any bigger now */
                maxcode = maxmaxcode;
            else
                maxcode = MAXCODE(n_bits);
        }
        if (clear_flg > 0) {
            maxcode = MAXCODE(n_bits = INIT_BITS);
            clear_flg = 0;
        }
        size = fread(buf, 1, n_bits, inp);

        if (size <= 0) {
            if (feof(inp)) {
                /* end of file */
                return (-1);
            } else if (ferror(inp)) {
                ioerror();
            }
        }

        offset = 0;
        /* Round size down to integral number of codes */
        size = (size << 3) - (n_bits - 1);
    }
    r_off = offset;
    bits = n_bits;
    /*
     * Get to the first byte.
     */
    bp += (r_off >> 3);
    r_off &= 7;
    /* Get first part (low order bits) */
    code = (*bp++ >> r_off);
    bits -= (8 - r_off);
    r_off = 8 - r_off;      /* now, offset into code word */
    /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
    if (bits >= 8) {
        code |= *bp++ << r_off;
        r_off += 8;
        bits -= 8;
    }
    /* high order bits. */
    code |= (*bp & rmask[bits]) << r_off;
    offset += n_bits;

    return (code);
}

#ifdef DEBUG
static void
printcodes()
{
    /*
     * Just print out codes from input file.  For debugging.
     */
    code_int code;
    int col = 0, bits;

    bits = n_bits = INIT_BITS;
    maxcode = MAXCODE(n_bits);
    free_ent = ((block_compress) ? FIRST : 256);
    while ((code = getcode()) >= 0) {
        if ((code == CLEAR) && block_compress) {
            free_ent = FIRST - 1;
            clear_flg = 1;
        } else if (free_ent < maxmaxcode)
            free_ent++;
        if (bits != n_bits) {
            (void) fprintf(stderr, "\nChange to %d bits\n", n_bits);
            bits = n_bits;
            col = 0;
        }
        (void) fprintf(stderr, "%5d%c",
            code, (col += 6) >= 74 ? (col = 0, '\n') : ' ');
    }
    (void) putc('\n', stderr);
}

#endif /* DEBUG */

#ifdef DEBUG
static void
dump_tab()  /* dump string table */
{
    int i, first;
    int ent;
    int stack_top = STACK_SIZE;
    int c;

    if (do_decomp == 0) {   /* compressing */
        int flag = 1;

        for (i = 0; i < hsize; i++) {   /* build sort pointers */
            if ((long)htabof(i) >= 0) {
                sorttab[codetabof(i)] = i;
            }
        }
        first = block_compress ? FIRST : 256;
        for (i = first; i < free_ent; i++) {
            (void) fprintf(stderr, "%5d: \"", i);
            de_stack[--stack_top] = '\n';
            de_stack[--stack_top] = '"';
            stack_top =
                in_stack((htabof(sorttab[i]) >> maxbits) & 0xff,
                stack_top);
            for (ent = htabof(sorttab[i]) & ((1 << maxbits) -1);
                ent > 256;
                ent = htabof(sorttab[ent]) & ((1<<maxbits)-1)) {
                stack_top = in_stack(
                    htabof(sorttab[ent]) >> maxbits,
                    stack_top);
            }
            stack_top = in_stack(ent, stack_top);
            (void) fwrite(&de_stack[stack_top], 1,
                STACK_SIZE - stack_top, stderr);
            stack_top = STACK_SIZE;
        }
    } else if (!debug) {    /* decompressing */

        for (i = 0; i < free_ent; i++) {
            ent = i;
            c = tab_suffixof(ent);
            if (isascii(c) && isprint(c))
                (void) fprintf(stderr, "%5d: %5d/'%c'  \"",
                    ent, tab_prefixof(ent), c);
            else
                (void) fprintf(stderr, "%5d: %5d/\\%03o \"",
                    ent, tab_prefixof(ent), c);
            de_stack[--stack_top] = '\n';
            de_stack[--stack_top] = '"';
            for (; ent != NULL;
                ent = (ent >= FIRST ? tab_prefixof(ent) :
                NULL)) {
                stack_top = in_stack(tab_suffixof(ent),
                    stack_top);
            }
            (void) fwrite(&de_stack[stack_top], 1,
                STACK_SIZE - stack_top, stderr);
            stack_top = STACK_SIZE;
        }
    }
}

#endif /* DEBUG */
#ifdef DEBUG
static int
in_stack(int c, int stack_top)
{
    if ((isascii(c) && isprint(c) && c != '\\') || c == ' ') {
        de_stack[--stack_top] = c;
    } else {
        switch (c) {
        case '\n': de_stack[--stack_top] = 'n'; break;
        case '\t': de_stack[--stack_top] = 't'; break;
        case '\b': de_stack[--stack_top] = 'b'; break;
        case '\f': de_stack[--stack_top] = 'f'; break;
        case '\r': de_stack[--stack_top] = 'r'; break;
        case '\\': de_stack[--stack_top] = '\\'; break;
        default:
            de_stack[--stack_top] = '0' + c % 8;
            de_stack[--stack_top] = '0' + (c / 8) % 8;
            de_stack[--stack_top] = '0' + c / 64;
            break;
        }
        de_stack[--stack_top] = '\\';
    }
    return (stack_top);
}

#endif /* DEBUG */
static void
ioerror()
{
    longjmp(env, 1);
}

static void
copystat(char *ifname, struct stat *ifstat, char *ofname)
{
    mode_t mode;
    struct utimbuf timep;
    acl_t *aclp = NULL;
    int error;

    if (fclose(outp)) {
        perror(ofname);
        if (!quiet) {
            (void) fprintf(stderr, gettext(" -- file unchanged"));
            newline_needed = 1;
        }
        perm_stat = 1;
    } else if (ifstat == NULL) {    /* Get stat on input file */
        perror(ifname);
        return;
    } else if ((ifstat->st_mode &
        S_IFMT /* 0170000 */) != S_IFREG /* 0100000 */) {
        if (quiet) {
            (void) fprintf(stderr, "%s: ", ifname);
        }
        (void) fprintf(stderr, gettext(
            " -- not a regular file: unchanged"));
        newline_needed = 1;
        perm_stat = 1;
    } else if (ifstat->st_nlink > 1) {
        if (quiet) {
            (void) fprintf(stderr, "%s: ", ifname);
        }
        (void) fprintf(stderr, gettext(
            " -- has %d other links: unchanged"),
            (uint_t)ifstat->st_nlink - 1);
        newline_needed = 1;
        perm_stat = 1;
    } else if (didnt_shrink && !force) {
        /* No compression: remove file.Z */
        if (!quiet) {
            (void) fprintf(stderr, gettext(
                " -- file unchanged"));
            newline_needed = 1;
        }
    } else if ((pathconf(ifname, _PC_XATTR_EXISTS) == 1) &&
        (mv_xattrs(ifname, ofname, 0) < 0)) {
        (void) fprintf(stderr, gettext(
            "%s: -- cannot preserve extended attributes, "
            "file unchanged"), ifname);
        newline_needed = 1;
        /* Move attributes back ... */
        (void) mv_xattrs(ofname, ifname, 1);
        perm_stat = 1;
    } else {    /* ***** Successful Compression ***** */
        mode = ifstat->st_mode & 07777;
        if (chmod(ofname, mode))     /* Copy modes */
            perror(ofname);

        error = acl_get(ifname, ACL_NO_TRIVIAL, &aclp);
        if (error != 0) {
            (void) fprintf(stderr, gettext(
                "%s: failed to retrieve acl : %s\n"),
                ifname, acl_strerror(error));
            perm_stat = 1;
        }
        if (aclp && (acl_set(ofname, aclp) < 0)) {
            (void) fprintf(stderr, gettext("%s: failed to set acl "
                "entries\n"), ofname);
            perm_stat = 1;
        }
        if (aclp) {
            acl_free(aclp);
            aclp = NULL;
        }

        /* Copy ownership */
        (void) chown(ofname, ifstat->st_uid, ifstat->st_gid);
        timep.actime = ifstat->st_atime;
        timep.modtime = ifstat->st_mtime;
        /* Update last accessed and modified times */
        (void) utime(ofname, &timep);
        if (unlink(ifname)) /* Remove input file */
            perror(ifname);
        if (!quiet) {
            (void) fprintf(stderr, gettext(
                " -- replaced with %s"), ofname);
            newline_needed = 1;
        }
        return;     /* Successful return */
    }

    /* Unsuccessful return -- one of the tests failed */
    if (ofname[0] != '\0') {
        if (unlink(ofname)) {
            perror(ofname);
        }

        ofname[0] = '\0';
    }
}

static void
onintr()
{
    if (!precious && !use_stdout && ofname[0] != '\0')
        (void) unlink(ofname);
    exit(1);
}

static void
oops()  /* wild pointer -- assume bad input */
{
    if (do_decomp) {
        (void) fprintf(stderr, gettext("uncompress: corrupt input\n"));
    }

    if (!use_stdout && ofname[0] != '\0') {
        (void) unlink(ofname);
    }

    exit(1);
}

static void
cl_block(count_long in_count)   /* table clear for block compress */
{
    count_long rat;

    checkpoint = (count_long)in_count + (count_long)CHECK_GAP;
#ifdef DEBUG
    if (debug) {
        (void) fprintf(stderr, "count: %lld, ratio: ",
            (count_long)in_count);
        prratio(stderr, (count_long)in_count, (count_long)bytes_out);
        (void) fprintf(stderr, "\n");
    }
#endif /* DEBUG */

    /* shift will overflow */
    if ((count_long)in_count > 0x007fffffffffffffLL) {
        rat = (count_long)bytes_out >> 8;
        if (rat == 0) {     /* Don't divide by zero */
            rat = 0x7fffffffffffffffLL;
        } else {
            rat = (count_long)in_count / (count_long)rat;
        }
    } else {
        /* 8 fractional bits */
        rat = ((count_long)in_count << 8) /(count_long)bytes_out;
    }
    if (rat > ratio) {
        ratio = rat;
    } else {
        ratio = 0;
#ifdef DEBUG
        if (verbose)
            dump_tab(); /* dump string table */
#endif
        cl_hash((count_int) hsize);
        free_ent = FIRST;
        clear_flg = 1;
        output((code_int) CLEAR);
#ifdef DEBUG
        if (debug)
            (void) fprintf(stderr, "clear\n");
#endif /* DEBUG */
    }
}

static void
cl_hash(count_int hsize)        /* reset code table */
{
    count_int *htab_p = htab+hsize;
    long i;
    long m1 = -1;

    i = hsize - 16;
    do {                /* might use Sys V memset(3) here */
        *(htab_p-16) = m1;
        *(htab_p-15) = m1;
        *(htab_p-14) = m1;
        *(htab_p-13) = m1;
        *(htab_p-12) = m1;
        *(htab_p-11) = m1;
        *(htab_p-10) = m1;
        *(htab_p-9) = m1;
        *(htab_p-8) = m1;
        *(htab_p-7) = m1;
        *(htab_p-6) = m1;
        *(htab_p-5) = m1;
        *(htab_p-4) = m1;
        *(htab_p-3) = m1;
        *(htab_p-2) = m1;
        *(htab_p-1) = m1;
        htab_p -= 16;
    } while ((i -= 16) >= 0);
        for (i += 16; i > 0; i--)
            *--htab_p = m1;
}

static void
prratio(FILE *stream, count_long num, count_long den)
{
    int q;  /* store percentage */

    q = (int)(10000LL * (count_long)num / (count_long)den);
    if (q < 0) {
        (void) putc('-', stream);
        q = -q;
    }
    (void) fprintf(stream, "%d%s%02d%%", q / 100,
        localeconv()->decimal_point, q % 100);
}

static void
version()
{
    (void) fprintf(stderr, "%s, Berkeley 5.9 5/11/86\n", rcs_ident);
    (void) fprintf(stderr, "Options: ");
#ifdef DEBUG
    (void) fprintf(stderr, "DEBUG, ");
#endif
    (void) fprintf(stderr, "BITS = %d\n", BITS);
}

static void
Usage()
{
#ifdef DEBUG
    (void) fprintf(stderr,
    "Usage: compress [-dDVfc] [-b maxbits] [file ...]\n");
#else
    if (strcmp(progname, "compress") == 0) {
        (void) fprintf(stderr,
            gettext(
            "Usage: compress [-fv] [-b maxbits] [file ...]\n"\
            "       compress [-cfv] [-b maxbits] [file]\n"));
    } else if (strcmp(progname, "uncompress") == 0)
        (void) fprintf(stderr, gettext(
            "Usage: uncompress [-cfv] [file ...]\n"));
    else if (strcmp(progname, "zcat") == 0)
        (void) fprintf(stderr, gettext("Usage: zcat [file ...]\n"));

#endif /* DEBUG */
}

static char *
local_basename(char *path)
{
    char *p;
    char *ret = (char *)path;

    while ((p = (char *)strpbrk(ret, "/")) != NULL)
        ret = p + 1;
    return (ret);
}

static int
addDotZ(char *fn, size_t fnsize)
{
    char *fn_dup;
    char *dir;
    long int max_name;
    long int max_path;

    fn_dup = strdup(fn);
    dir = dirname(fn_dup);
    max_name = pathconf(dir, _PC_NAME_MAX);
    max_path = pathconf(dir, _PC_PATH_MAX);
    free(fn_dup);

    /* Check for component length too long */

    if ((strlen(local_basename(fn)) + 2) > (size_t)max_name) {
        (void) fprintf(stderr,
            gettext("%s: filename too long to tack on .Z:"
            " %s\n"), progname, fn);
        return (-1);
    }

    /* Check for path length too long */

    if ((strlen(fn) + 2) > (size_t)max_path - 1) {
        (void) fprintf(stderr,
            gettext("%s: Pathname too long to tack on .Z:"
            " %s\n"), progname, fn);
        return (-1);
    }

    if (strlcat(fn, ".Z", fnsize) >= fnsize) {
        (void) fprintf(stderr,
            gettext("%s: Buffer overflow adding .Z to %s\n"),
            progname, fn);
        return (-1);
    }

    return (0);
}

/*
 * mv_xattrs - move (via renameat) all of the extended attributes
 *  associated with the file infile to the file outfile.
 *  This function returns 0 on success and -1 on error.
 */
static int
mv_xattrs(char *infile, char *outfile, int silent)
{
    int indfd, outdfd, tmpfd;
    DIR *dirp = NULL;
    struct dirent *dp = NULL;
    int error = 0;
    char *etext;

    indfd = outdfd = tmpfd = -1;

    if ((indfd = attropen(infile, ".", O_RDONLY)) == -1) {
        etext = gettext("cannot open source");
        error = -1;
        goto out;
    }

    if ((outdfd = attropen(outfile, ".", O_RDONLY)) == -1) {
        etext = gettext("cannot open target");
        error = -1;
        goto out;
    }

    if ((tmpfd = dup(indfd)) == -1) {
        etext = gettext("cannot dup descriptor");
        error = -1;
        goto out;

    }
    if ((dirp = fdopendir(tmpfd)) == NULL) {
        etext = gettext("cannot access source");
        error = -1;
        goto out;
    }

    while (dp = readdir(dirp)) {
        if ((dp->d_name[0] == '.' && dp->d_name[1] == '\0') ||
            (dp->d_name[0] == '.' && dp->d_name[1] == '.' &&
            dp->d_name[2] == '\0'))
            continue;
        if ((renameat(indfd, dp->d_name, outdfd, dp->d_name)) == -1) {
            etext = dp->d_name;
            error = -1;
            goto out;
        }
    }
out:
    if (error == -1 && silent == 0) {
        if (quiet) {
            (void) fprintf(stderr, "%s: ", infile);
        } else {
            (void) fprintf(stderr, ", ");
        }
        (void) fprintf(stderr, gettext("extended attribute error: "));
        perror(etext);
    }
    if (dirp)
        (void) closedir(dirp);
    if (indfd != -1)
        (void) close(indfd);
    if (outdfd != -1)
        (void) close(outdfd);
    return (error);
}