cmd/pg/pg.c

	pg.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

#include <signal.h>
#include <setjmp.h>
#include <sys/types.h>
#include <sys/dirent.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <ctype.h>
#include <stdio.h>
#include <wchar.h>
#include <curses.h>
#include <term.h>
#include <errno.h>
#include <stdlib.h>
#include <regexpr.h>
#include <limits.h>
#include <locale.h>
#include <wctype.h> /* iswprint() */
#include <string.h>
#include <unistd.h>
#include <wait.h>
#include <libw.h>
#include <regexpr.h>


/*
 *  pg -- paginator for crt terminals
 *
 *  Includes the ability to display pages that have
 *  already passed by. Also gives the user the ability
 *  to search forward and backwards for regular expressions.
 *  This works for piped input by copying to a temporary file,
 *  and resolving backreferences from there.
 *
 *  Note:   The reason that there are so many commands to do
 *      the same types of things is to try to accommodate
 *      users of other paginators.
 */

#define LINSIZ  1024
#define QUIT    '\034'
#define BOF (EOF - 1)   /* Begining of File */
#define STOP    (EOF - 2)
#define PROMPTSIZE  256

/*
 * Function definitions
 */
static  void    lineset(int);
static  char    *setprompt();
static  int set_state(int *, wchar_t, char *);
static  void    help();
static  void    copy_file(FILE *, FILE *);
static  void    re_error(int);
static  void    save_input(FILE *);
static  void    save_pipe();
static  void    newdol(FILE *);
static  void    erase_line(int);
static  void    kill_line();
static  void    doclear();
static  void    sopr(char *, int);
static  void    prompt(char *);
static  void    error(char *);
static  void    terminit();
static  void    compact();
static  off_t   getline(FILE *);
static  int mrdchar();
static  off_t   find(int, off_t);
static  int search(char *, off_t);
static  FILE    *checkf(char *);
static  int skipf(int);
static  int readch();
static  int ttyin();
static  int number();
static  int command(char *);
static  int screen(char *);
static  int fgetputc();
static  char    *pg_strchr();


struct line {           /* how line addresses are stored */
    off_t   l_addr;     /* file offset */
    off_t   l_no;       /* line number in file */
};

typedef struct line LINE;

static  LINE    *zero = NULL,   /* first line */
        *dot,       /* current line */
        *dol,       /* last line */
        *contig;    /* where contiguous (non-aged) lines start */
static  long    nlall;      /* room for how many LINEs in memory */

static  FILE    *in_file,   /* current input stream */
        *tmp_fin,   /* pipe temporary file in */
        *tmp_fou;   /* pipe temporary file out */
static  char    tmp_name[] = "/tmp/pgXXXXXX";

static  short   sign;       /* sign of command input */

static  int fnum,       /* which file argument we're in */
        pipe_in,    /* set when stdin is a pipe */
        out_is_tty; /* set if stdout is a tty */
static  gid_t   my_pgid;

static  void    on_brk(),
        end_it();
static  short   brk_hit;    /* interrupt handling is pending flag */

static  int window = 0; /* window size in lines */
static  short   eof_pause = 1;  /* pause w/ prompt at end of files */
static  short   rmode = 0;  /* deny shell escape in restricted mode */
static  short   soflag = 0; /* output all messages in standout mode */
static  short   promptlen;  /* length of the current prompt */
static  short   firstf = 1; /* set before first file has been processed */
static  short   inwait,     /* set while waiting for user input */
        errors;     /* set if error message has been printed. */
                /* if so, need to erase it and prompt */

static  char    **fnames;
static  short   status = 0; /* set > 0 if error detected */
static  short   fflag = 0;  /* set if the f option is used */
static  short   nflag = 0;  /* set for "no newline" input option */
static  short   clropt = 0; /* set if the clear option is used */
static  int initopt = 0;    /* set if the line option is used */
static  int srchopt = 0;    /* set if the search option is used */
static  int initline;
static  char    initbuf[BUFSIZ];
static  wchar_t leave_search = L't';
                /* where on the page to leave a found string */
static  short   nfiles;
static  char    *shell;
static  char    *promptstr = ":";
static  off_t   nchars;         /* return from getline in find() */
static  jmp_buf restore;
static  char    Line[LINSIZ+2];

static  int catch_susp;

static  void    onsusp();

struct screen_stat {
    off_t   first_line;
    off_t   last_line;
    short   is_eof;
    };

static  struct screen_stat old_ss = { 0, 0, 0 };
static  struct screen_stat new_ss;
static  struct termio otty; /* to save old terminal settings */

static  short   termflg = 0;    /* set once terminal is initialized */
static  short   eoflag;     /* set whenever at end of current file */
static  short   doliseof;   /* set when last line of file is known */
static  off_t   eofl_no;    /* what the last line of the file is */
static  void    usage(void);
static FILE *pg_stdin;

main(argc, argv)
int argc;
char *argv[];
{
    char    *s;
    char    *p;
    int     prnames = 0;
    int     opt;
    int     i;

    (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);

    /* check for non-standard "-#" option */
    for (i = 1; i < argc; i++) {
        if (strcmp(argv[i], "--") == 0)
            break;

        if ((argv[i][0] == '-') && isdigit(argv[i][1])) {
            if (strlen(&argv[i][1]) !=
                strspn(&argv[i][1], "0123456789")) {
                (void) fprintf(stderr, gettext(
                    "pg: Badly formed number\n"));
                usage();
            }

            window = (int)strtol(&argv[i][1], (char **)NULL, 10);

            while (i < argc) {
                argv[i] = argv[i + 1];
                i++;
            }
            i--;
            argc--;
        }
    }

    /* check for non-standard + option */
    for (i = 1; i < argc; i++) {
        if (strcmp(argv[i], "--") == 0)
        break;

        if (argv[i][0] == '+') {
            if (argv[i][1] == '/') {
                srchopt++;
                initopt = 0;
                for (s = &argv[i][2], p = initbuf; *s != '\0'; )
                    if (p < initbuf + sizeof (initbuf))
                        *p++ = *s++;
                    else {
                        (void) fprintf(stderr, gettext(
                            "pg: pattern too long\n"));
                        return (1);
                    }
                *p = '\0';
            } else {
                initopt++;
                srchopt = 0;
                s = &argv[i][2];
                for (; isdigit(*s); s++)
                    initline = initline*10 + *s -'0';
                if (*s != '\0')
                    usage();
            }

            while (i < argc) {
                argv[i] = argv[i + 1];
                i++;
            }
            i--;
            argc--;
        }
    }

    while ((opt = getopt(argc, argv, "cefnrsp:")) != EOF) {
        switch (opt) {
        case 'c':
            clropt = 1;
            break;

        case 'e':
            eof_pause = 0;
            break;

        case 'f':
            fflag = 1;
            break;

        case 'n':
            nflag = 1;
            break;

        case 'r':
            rmode = 1;  /* restricted mode */
            break;

        case 's':
            soflag = 1; /* standout mode */
            break;

        case 'p':
            promptstr = setprompt(optarg);
            break;

        default:
            usage();
        }
    }

    nfiles = argc - optind;
    fnames = &argv[optind];

    (void) signal(SIGQUIT, end_it);
    (void) signal(SIGINT, end_it);
    out_is_tty = isatty(1);
    my_pgid = getpgrp();
    if (out_is_tty) {
        terminit();
        (void) signal(SIGQUIT, on_brk);
        (void) signal(SIGINT, on_brk);
        if (signal(SIGTSTP, SIG_IGN) == SIG_DFL) {
            (void) signal(SIGTSTP, onsusp);
            catch_susp++;
        }
    }
    if (window == 0)
        window = lines - 1;
    if (window <= 1)
        window = 2;
    if (initline <= 0)
        initline = 1;
    if (nfiles > 1)
        prnames++;

    if (nfiles == 0) {
        fnames[0] = "-";
        nfiles++;
    }
    while (fnum < nfiles) {
        if (strcmp(fnames[fnum], "") == 0)
            fnames[fnum] = "-";
        if ((in_file = checkf(fnames[fnum])) == NULL)
        {
            status = 2;
            fnum++;
        } else {
            status = 0;
            if (out_is_tty)
                fnum += screen(fnames[fnum]);
            else {
                if (prnames) {
                    (void) fputs("::::::::::::::\n",
                        stdout);
                    (void) fputs(fnames[fnum], stdout);
                    (void) fputs("\n::::::::::::::\n",
                        stdout);
                }
                copy_file(in_file, stdout);
                fnum++;
            }
            (void) fflush(stdout);
            if (pipe_in)
                save_pipe();
            else
            if (in_file != tmp_fin)
                (void) fclose(in_file);
        }
    }
    end_it();

    /*NOTREACHED*/
    return (0);
}

static  char *
setprompt(s)
char *s;
{
    int i = 0;
    int pct_d = 0;
    static char pstr[PROMPTSIZE];

    while (i < PROMPTSIZE - 2)
        switch (pstr[i++] = *s++) {
        case '\0':
            return (pstr);
        case '%':
            if (*s == 'd' && !pct_d) {
                pct_d++;
            } else if (*s != '%')
                pstr[i++] = '%';
            if ((pstr[i++] = *s++) == '\0')
                return (pstr);
            break;
        default:
            break;
        }
    (void) fprintf(stderr, gettext("pg: prompt too long\n"));
    exit(1);
    /*NOTREACHED*/
}


/*
 * Print out the contents of the file f, one screenful at a time.
 */

static int
screen(file_name)
char *file_name;
{
    int cmd_ret = 0;
    off_t start;
    short hadchance = 0;

    old_ss.is_eof = 0;
    old_ss.first_line = 0;
    old_ss.last_line = 0;
    new_ss = old_ss;
    if (!firstf)
        cmd_ret = command(file_name);
    else {
        firstf = 0;
        if (initopt) {
            initopt = 0;
            new_ss.first_line = initline;
            new_ss.last_line = initline + (off_t)window - 1;
        } else if (srchopt) {
            srchopt = 0;
            if (!search(initbuf, (off_t)1))
                cmd_ret = command(file_name);
        } else {
            new_ss.first_line = 1;
            new_ss.last_line = (off_t)window;
        }
    }

    for (;;) {
        if (cmd_ret)
            return (cmd_ret);
        if (hadchance && new_ss.last_line >= eofl_no)
            return (1);
        hadchance = 0;

        if (new_ss.last_line < (off_t)window)
            new_ss.last_line = (off_t)window;
        if (find(0, new_ss.last_line + 1) != EOF)
            new_ss.is_eof = 0;
        else {
            new_ss.is_eof = 1;
            new_ss.last_line = eofl_no - 1;
            new_ss.first_line = new_ss.last_line -
                (off_t)window + 1;
        }

        if (new_ss.first_line < 1)
            new_ss.first_line = 1;
        if (clropt) {
            doclear();
            start = new_ss.first_line;
        } else {
            if (new_ss.first_line == old_ss.last_line)
                start = new_ss.first_line + 1;
            else
            if (new_ss.first_line > old_ss.last_line)
                start = new_ss.first_line;
            else
            if (old_ss.first_line < new_ss.first_line)
                start = old_ss.last_line + 1;
            else
                start = new_ss.first_line;

            if (start < old_ss.first_line)
                sopr(gettext("...skipping backward\n"), 0);
            else
            if (start > old_ss.last_line + 1)
                sopr(gettext("...skipping forward\n"), 0);
        }

        for (; start <= new_ss.last_line; start++) {
            (void) find(0, start);
            (void) fputs(Line, stdout);
            if (brk_hit) {
                new_ss.last_line = find(1, 0);
                new_ss.is_eof = 0;
                break;
            }
        }

        brk_hit = 0;
        (void) fflush(stdout);
        if (new_ss.is_eof) {
            if (!eof_pause || eofl_no == 1)
                return (1);
            hadchance++;
            error("(EOF)");
        }
        old_ss = new_ss;
        cmd_ret = command((char *)NULL);
    }
}

static  char    cmdbuf[LINSIZ], *cmdptr;
#define BEEP()      if (bell) { (void) putp(bell); (void) fflush(stdout); }
#define BLANKS(p)   while (*p == ' ' || *p == '\t') p++
#define CHECKEND()  BLANKS(cmdptr); if (*cmdptr) { BEEP(); break; }

/*
 * Read a command and do it. A command consists of an optional integer
 * argument followed by the command character.  Return the number of files
 * to skip, 0 if we're still talking about the same file.
 */

static int
command(filename)
char *filename;
{
    off_t nlines;
    FILE *sf;
    char *cmdend;
    pid_t id;
    int skip;
    int len;
    wchar_t wc;
    wchar_t wc_e;
    wchar_t wc_e1;
    char    *p;

    for (;;) {
        /*
         * Wait for output to drain before going on.
         * This is done so that the user will not hit
         * break and quit before he has seen the prompt.
         */
        (void) ioctl(1, TCSBRK, 1);
        if (setjmp(restore) > 0)
            end_it();
        inwait = 1;
        brk_hit = 0;
        if (errors)
            errors = 0;
        else {
            kill_line();
            prompt(filename);
        }
        (void) fflush(stdout);
        if (ttyin())
            continue;
        cmdptr = cmdbuf;
        nlines = number();
        BLANKS(cmdptr);

        if ((len = mbtowc(&wc, cmdptr, MB_CUR_MAX)) <= 0) {
            wc = *cmdptr;
            len = 1;
        }
        cmdptr += len;
        switch (wc) {
        case 'h':
            CHECKEND();
            help();
            break;
        case '\014': /* ^L */
        case '.':   /* redisplay current window */
            CHECKEND();
            new_ss.first_line = old_ss.first_line;
            new_ss.last_line = old_ss.last_line;
            inwait = 0;
            return (0);
        case 'w':   /* set window size */
        case 'z':
            if (sign == -1) {
                BEEP();
                break;
            }
            CHECKEND();
            if (nlines == 0)
                nlines = (off_t)window;
            else
            if (nlines > 1)
                window = (int)nlines;
            else {
                BEEP();
                break;
            }
            new_ss.first_line = old_ss.last_line;
            new_ss.last_line = new_ss.first_line +
                (off_t)window - 1;
            inwait = 0;
            return (0);
        case '\004': /* ^D */
        case 'd':
            CHECKEND();
            if (sign == 0)
                sign = 1;
            new_ss.last_line = old_ss.last_line +
                (off_t)sign*window/2;
            new_ss.first_line = new_ss.last_line -
                (off_t)window + 1;
            inwait = 0;
            return (0);
        case 's':
            /*
             * save input in filename.
             * Check for filename, access, etc.
             */
            BLANKS(cmdptr);
            if (!*cmdptr) {
                BEEP();
                break;
            }
            if (setjmp(restore) > 0) {
                BEEP();
            } else {
                char outstr[PROMPTSIZE];
                if ((sf = fopen(cmdptr, "w")) == NULL) {
                    error("cannot open save file");
                    break;
                }
                kill_line();
                (void) sprintf(outstr, gettext(
                    "saving file %s"), cmdptr);
                sopr(outstr, 1);
                (void) fflush(stdout);
                save_input(sf);
                error("saved");
            }
            (void) fclose(sf);
            break;
        case 'q':
        case 'Q':
            CHECKEND();
            inwait = 0;
            end_it();
            /*FALLTHROUGH*/

        case 'f':   /* skip forward screenfuls */
            CHECKEND();
            if (sign == 0)
                sign++; /* skips are always relative */
            if (nlines == 0)
                nlines++;
            nlines = nlines * (window - 1);
            if (sign == 1)
                new_ss.first_line = old_ss.last_line + nlines;
            else
                new_ss.first_line = old_ss.first_line - nlines;
            new_ss.last_line = new_ss.first_line +
                (off_t)window - 1;
            inwait = 0;
            return (0);
        case 'l':   /* get a line */
            CHECKEND();
            if (nlines == 0) {
                nlines++;
                if (sign == 0)
                    sign = 1;
            }
            switch (sign) {
            case 1:
                new_ss.last_line = old_ss.last_line + nlines;
                new_ss.first_line =
                    new_ss.last_line - (off_t)window + 1;
                break;
            case 0:  /* leave addressed line at top */
                new_ss.first_line = nlines;
                new_ss.last_line = nlines + (off_t)window - 1;
                break;
            case -1:
                new_ss.first_line = old_ss.first_line - nlines;
                new_ss.last_line =
                    new_ss.first_line + (off_t)window - 1;
                break;
            }
            inwait = 0;
            return (0);
        case '\0': /* \n or blank */
            if (nlines == 0) {
                nlines++;
                if (sign == 0)
                    sign = 1;
            }
            nlines = (nlines - 1) * (window - 1);
            switch (sign) {
            case 1:
                new_ss.first_line = old_ss.last_line + nlines;
                new_ss.last_line =
                    new_ss.first_line + (off_t)window - 1;
                break;
            case 0:
                new_ss.first_line = nlines + 1;
                new_ss.last_line = nlines + (off_t)window;
                /*
                 * This if statement is to fix the obscure bug
                 * where you have a file that has less lines
                 * than a screen holds, and the user types '1',
                 * expecting to have the 1st page (re)displayed.
                 * If we didn't set the new last_line to
                 * eofl_no-1, the screen() routine
                 * would cause pg to exit.
                 */
                if (new_ss.first_line == 1 &&
                    new_ss.last_line >= eofl_no)
                    new_ss.last_line = eofl_no - 1;
                break;
            case -1:
                new_ss.last_line = old_ss.first_line - nlines;
                new_ss.first_line =
                    new_ss.last_line - (off_t)window + 1;
                break;
            }
            inwait = 0;
            return (0);
        case 'n':   /* switch to next file in arglist */
            CHECKEND();
            if (sign == 0)
                sign = 1;
            if (nlines == 0)
                nlines++;
            if ((skip = skipf(sign *nlines)) == 0) {
                BEEP();
                break;
            }
            inwait = 0;
            return (skip);
        case 'p':   /* switch to previous file in arglist */
            CHECKEND();
            if (sign == 0)
                sign = 1;
            if (nlines == 0)
                nlines++;
            if ((skip = skipf(-sign * nlines)) == 0) {
                BEEP();
                break;
            }
            inwait = 0;
            return (skip);
        case '$':   /* go to end of file */
            CHECKEND();
            sign = 1;
            while (find(1, (off_t)10000) != EOF)
                /* any large number will do */;
            new_ss.last_line = eofl_no - 1;
            new_ss.first_line = eofl_no - (off_t)window;
            inwait = 0;
            return (0);
        case '/':   /* search forward for r.e. */
        case '?':   /*   "  backwards */
        case '^':   /* this ones a ? for regent100s */
            if (sign < 0) {
                BEEP();
                break;
            }
            if (nlines == 0)
                nlines++;
            cmdptr--;
            cmdend = cmdptr + (strlen(cmdptr) - 1);
            wc_e1 = -1;
            wc_e = -1;
            for (p = cmdptr; p <= cmdend; p += len) {
                wc_e1 = wc_e;
                if ((len = mbtowc(&wc_e, p, MB_CUR_MAX)) <= 0) {
                    wc_e = *p;
                    len = 1;
                }
            }

            if (cmdend > cmdptr + 1) {
                if ((wc_e1 == *cmdptr) &&
                    ((wc_e == L't') ||
                    (wc_e == L'm') || (wc_e == L'b'))) {
                    leave_search = wc_e;
                    wc_e = wc_e1;
                    cmdend--;
                }
            }
            if ((cmdptr < cmdend) && (wc_e == *cmdptr))
                *cmdend = '\0';
            if (*cmdptr != '/')  /* signify back search by - */
                nlines = -nlines;
            if (!search(++cmdptr, (off_t)nlines))
                break;
            else {
                inwait = 0;
                return (0);
            }
        case '!':   /* shell escape */
            if (rmode) {    /* restricted mode */
                (void) fprintf(stderr, gettext(
                "!command not allowed in restricted mode.\n"));
                break;
            }
            if (!hard_copy) { /* redisplay the command */
                (void) fputs(cmdbuf, stdout);
                (void) fputs("\n", stdout);
            }
            if ((id = fork()) < 0) {
                error("cannot fork, try again later");
                break;
            }
            if (id == (pid_t)0) {
                /*
                 * if stdin is a pipe, need to close it so
                 * that the terminal is really stdin for
                 * the command
                 */
                (void) fclose(stdin);
                (void) fclose(pg_stdin);
                (void) dup(fileno(stdout));
                (void) execl(shell, shell, "-c", cmdptr, 0);
                (void) perror("exec");
                exit(1);
            }
            (void) signal(SIGINT, SIG_IGN);
            (void) signal(SIGQUIT, SIG_IGN);
            if (catch_susp)
                (void) signal(SIGTSTP, SIG_DFL);
            while (wait((int *)0) != id);
            {
                if (errno == ECHILD)
                    break;
                else
                    errno = 0;
            }
            (void) fputs("!\n", stdout);
            (void) fflush(stdout);
            (void) signal(SIGINT, on_brk);
            (void) signal(SIGQUIT, on_brk);
            if (catch_susp)
                (void) signal(SIGTSTP, onsusp);
            break;
        default:
            BEEP();
            break;
        }
    }
}

static int
number()
{
    int i;
    char *p;

    i = 0;
    sign = 0;
    p = cmdptr;
    BLANKS(p);
    if (*p == '+') {
        p++;
        sign = 1;
    }
    else
    if (*p == '-') {
        p++;
        sign = -1;
    }
    while (isdigit(*p))
        i = i * 10 + *p++ - '0';
    cmdptr = p;
    return (i);
}

static int
ttyin()
{
    char *sptr, *p;
    wchar_t ch;
    int slash = 0;
    int state = 0;
    int width, length;
    char multic[MB_LEN_MAX];
    static  int readch();
    int     len;

    (void) fixterm();
    /* initialize state processing */
    (void) set_state(&state, ' ', (char *)0);
    sptr = cmdbuf;
    while (state != 10) {
        if ((ch = readch()) < 0 || !iswascii(ch) && !iswprint(ch)) {
            BEEP();
            continue;
        }

        if ((length = wctomb(multic, ch)) < 0)
            length = 0;
        multic[length] = 0;

        if (ch == '\n' && !slash)
            break;
        if (ch == erasechar() && !slash) {
            if (sptr > cmdbuf) {
                char *oldp = cmdbuf;
                wchar_t wchar;
                p = cmdbuf;
                while (p  < sptr) {
                    oldp = p;
                    len = mbtowc(&wchar, p, MB_CUR_MAX);
                    if (len <= 0) {
                        wchar = (unsigned char)*p;
                        len = 1;
                    }
                    p += len;
                }
                if ((width = wcwidth(wchar)) <= 0)
                    /* ascii control character */
                    width = 2;
                promptlen -= width;
                while (width--)
                    (void) fputs("\b \b", stdout);
                sptr = oldp;
            }
            (void) set_state(&state, ch, sptr);
            (void) fflush(stdout);
            continue;
        }
        else
        if (ch == killchar() && !slash) {
            if (hard_copy)
                (void) putwchar(ch);
            (void) resetterm();
            return (1);
        }
        if (ch < ' ')
            width = 2;
        else
            if ((width = wcwidth(ch)) <= 0)
                width = 0;
        if (slash) {
            slash = 0;
            (void) fputs("\b \b", stdout);
            sptr--;
            promptlen--;
        } else /* is there room to keep this character? */
        if (sptr >= cmdbuf + sizeof (cmdbuf) ||
            promptlen + width >= columns) {
            BEEP();
            continue;
        }
        else
        if (ch == '\\')
            slash++;
        if (set_state(&state, ch, sptr) == 0) {
            BEEP();
            continue;
        }
        (void) strncpy(sptr, multic, (size_t)length);
        sptr += length;
        if (ch < ' ') {
            ch += 0100;
            multic[0] = '^';
            multic[1] = ch;
            length = 2;
        }
        p = multic;
        while (length--)
            (void) putchar(*p++);
        promptlen += width;
        (void) fflush(stdout);
    }

    *sptr = '\0';
    kill_line();
    (void) fflush(stdout);
    (void) resetterm();
    return (0);
}

static  int
set_state(pstate, c, pc)
int *pstate;
wchar_t c;
char *pc;
{
    static char *psign;
    static char *pnumber;
    static char *pcommand;
    static int slash;

    if (*pstate == 0) {
        psign = (char *)NULL;
        pnumber = (char *)NULL;
        pcommand = (char *)NULL;
        *pstate = 1;
        slash = 0;
        return (1);
    }
    if (c == '\\' && !slash) {
        slash++;
        return (1);
    }
    if (c == erasechar() && !slash)
        switch (*pstate) {
        case 4:
            if (pc > pcommand)
                return (1);
            pcommand = (char *)NULL;
            /*FALLTHROUGH*/

        case 3:
            if (pnumber && pc > pnumber) {
                *pstate = 3;
                return (1);
            }
            pnumber = (char *)NULL;
            /*FALLTHROUGH*/

        case 2:
            if (psign && pc > psign) {
                *pstate = 2;
                return (1);
            }
            psign = (char *)NULL;
            /*FALLTHROUGH*/

        case 1:
            *pstate = 1;
            return (1);
        }

    slash = 0;
    switch (*pstate) {
    case 1: /* before recieving anything interesting */
        if (c == '\t' || (!nflag && c == ' '))
            return (1);
        if (c == '+' || c == '-') {
            psign = pc;
            *pstate = 2;
            return (1);
        }
        /*FALLTHROUGH*/

    case 2: /* recieved sign, waiting for digit */
        if (iswascii(c) && isdigit(c)) {
            pnumber = pc;
            *pstate = 3;
            return (1);
        }
        /*FALLTHROUGH*/

    case 3: /* recieved digit, waiting for the rest of the number */
        if (iswascii(c) && isdigit(c))
            return (1);
        if (iswascii(c) && pg_strchr("h\014.wz\004dqQfl np$", c)) {
            pcommand = pc;
            if (nflag)
                *pstate = 10;
            else
                *pstate = 4;
            return (1);
        }
        if (iswascii(c) && pg_strchr("s/^?!", c)) {
            pcommand = pc;
            *pstate = 4;
            return (1);
        }
        return (0);
    case 4:
        return (1);
    }
    return (0);
}

static  int
readch()
{
    return (fgetwc(pg_stdin));
}

static void
help()
{
    if (clropt)
        doclear();

    (void) fputs(gettext(
"-------------------------------------------------------\n"
"  h                     help\n"
"  q or Q                quit\n"
"  <blank> or <newline>  next page\n"
"  l                     next line\n"
"  d or <^D>             display half a page more\n"
"  . or <^L>             redisplay current page\n"
"  f                     skip the next page forward\n"
"  n                     next file\n"
"  p                     previous file\n"
"  $                     last page\n"
"  w or z                set window size and display next page\n"
"  s savefile            save current file in savefile\n"
"  /pattern/             search forward for pattern\n"
"  ?pattern? or\n"
"  ^pattern^             search backward for pattern\n"
"  !command              execute command\n"
"\n"
"Most commands can be preceeded by a number, as in:\n"
"+1<newline> (next page); -1<newline> (previous page); 1<newline> (page 1).\n"
"\n"
"See the manual page for more detail.\n"
"-------------------------------------------------------\n"),
        stdout);
}

/*
 * Skip nskip files in the file list (from the command line). Nskip may be
 * negative.
 */

static int
skipf(nskip)
int nskip;
{
    if (fnum + nskip < 0) {
        nskip = -fnum;
        if (nskip == 0)
            error("No previous file");
    }
    else
    if (fnum + nskip > nfiles - 1) {
        nskip = (nfiles - 1) - fnum;
        if (nskip == 0)
            error("No next file");
    }
    return (nskip);
}

/*
 * Check whether the file named by fs is a file which the user may
 * access.  If it is, return the opened file. Otherwise return NULL.
 */

static FILE *
checkf(fs)
char *fs;
{
    struct stat stbuf;
    FILE *f;
    int fd;
    int f_was_opened;

    pipe_in = 0;
    if (strcmp(fs, "-") == 0) {
        if (tmp_fin == NULL)
            f = stdin;
        else {
            rewind(tmp_fin);
            f = tmp_fin;
        }
        f_was_opened = 0;
    } else {
        if ((f = fopen(fs, "r")) == (FILE *)NULL) {
            (void) fflush(stdout);
            perror(fs);
            return ((FILE *)NULL);
        }
        f_was_opened = 1;
    }
    if (fstat(fileno(f), &stbuf) == -1) {
        if (f_was_opened)
            (void) fclose(f);
        (void) fflush(stdout);
        perror(fs);
        return ((FILE *)NULL);
    }
    if ((stbuf.st_mode & S_IFMT) == S_IFDIR) {
        if (f_was_opened)
            (void) fclose(f);
        (void) fprintf(stderr, "pg: ");
        (void) fprintf(stderr, gettext("%s is a directory\n"), fs);
        return ((FILE *)NULL);
    }
    if ((stbuf.st_mode & S_IFMT) == S_IFREG) {
        if (f == stdin)     /* It may have been read from */
            rewind(f);  /* already, and not reopened  */
    } else {
        if (f != stdin) {
            if (f_was_opened)
                (void) fclose(f);
            (void) fprintf(stderr, "pg: ");
            (void) fprintf(stderr, gettext(
            "special files only handled as standard input\n"));
            return ((FILE *)NULL);
        } else {
            if ((fd = mkstemp(tmp_name)) < 0) {
                (void) perror(tmp_name);
                return ((FILE *)NULL);
            }
            (void) close(fd);
            if ((tmp_fou = fopen(tmp_name, "w")) == NULL) {
                (void) perror(tmp_name);
                return ((FILE *)NULL);
            }
            if ((tmp_fin = fopen(tmp_name, "r")) == NULL) {
                (void) perror(tmp_name);
                return ((FILE *)NULL);
            }
            pipe_in = 1;
        }
    }
    lineset(BOF);
    return (f);
}

static void
copy_file(f, out)
FILE *f, *out;
{
    int c;

    while ((c = getc(f)) != EOF)
        (void) putc(c, out);

}

static void
re_error(i)
int i;
{
    int j;
    static struct messages {
        char *message;
        int number;
        } re_errmsg[] = {
        "Pattern not found",                1,
        "Range endpoint too large",         11,
        "Bad number",                   16,
        "`\\digit' out of range",           25,
        "No remembered search string",          41,
        "\\( \\) imbalance",                42,
        "Too many \\(",                 43,
        "More than two numbers given in \\{ \\}",   44,
        "} expected after \\",              45,
        "First number exceeds second in \\{ \\}",   46,
        "[] imbalance",                 49,
        "Regular expression overflow",          50,
        "Illegal byte sequence",            67,
        "Bad regular expression",           0
        };

    for (j = 0; re_errmsg[j].number != 0; j++)
        if (re_errmsg[j].number == i)
            break;
    error(re_errmsg[j].message);
    longjmp(restore, 1);  /* restore to search() */
}

/*
 * Search for nth ocurrence of regular expression contained in buf in the file
 *  negative n implies backward search
 *  n 'guaranteed' non-zero
 */


static int
search(buf, n)
char buf[];
off_t n;
{
    int direction;
    static char *expbuf;
    char *nexpbuf;
    int END_COND;

    if (setjmp(restore) <= 0) {
        nexpbuf = compile(buf, (char *)0, (char *)0);
        if (regerrno) {
            if (regerrno != 41 || expbuf == NULL)
                re_error(regerrno);
        } else {
            if (expbuf)
                free(expbuf);
            expbuf = nexpbuf;
        }

        if (n < 0) {    /* search back */
            direction = -1;
            (void) find(0, old_ss.first_line);
            END_COND = BOF;
        } else {
            direction = 1;
            (void) find(0, old_ss.last_line);
            END_COND = EOF;
        }

        while (find(1, direction) != END_COND) {
            if (brk_hit)
                break;
            if (step(Line, expbuf))
                if ((n -= direction) == 0) {
                    switch (leave_search) {
                    case 't':
                        new_ss.first_line =
                            find(1, (off_t)0);
                        new_ss.last_line =
                            new_ss.first_line +
                            (off_t)window
                            - 1;
                        break;
                    case 'b':
                        new_ss.last_line =
                            find(1, (off_t)0);
                        new_ss.first_line =
                            new_ss.last_line -
                            (off_t)window
                            + 1;
                        break;
                    case 'm':
                        new_ss.first_line =
                            find(1, (off_t)0) -
                            ((off_t)window - 1)/2;
                        new_ss.last_line =
                            new_ss.first_line +
                            (off_t)window
                            - 1;
                        break;
                    }
                    return (1);
                }
        }
        re_error(1); /* Pattern not found */
    }
    BEEP();
    return (0);
}

/*
 *  find -- find line in file f, subject to certain constraints.
 *
 *  This is the reason for all the funny stuff with sign and nlines.
 *  We need to be able to differentiate between relative and abosolute
 *  address specifications.
 *
 *  So...there are basically three cases that this routine
 *  handles. Either line is zero, which  means there is to be
 *  no motion (because line numbers start at one), or
 *  how and line specify a number, or line itself is negative,
 *  which is the same as having how == -1 and line == abs(line).
 *
 *  Then, figure where exactly it is that we are going (an absolute
 *  line number). Find out if it is within what we have read,
 *  if so, go there without further ado. Otherwise, do some
 *  magic to get there, saving all the intervening lines,
 *  in case the user wants to see them some time later.
 *
 *  In any case, return the line number that we end up at.
 *  (This is used by search() and screen()). If we go past EOF,
 *  return EOF.
 *  This EOF will go away eventually, as pg is expanded to
 *  handle multiple files as one huge one. Then EOF will
 *  mean we have run off the file list.
 *  If the requested line number is too far back, return BOF.
 */

static off_t
find(how, line) /* find the line and seek there */
int how;
off_t line;
{
    /* no compacted memory yet */
    FILE *f = in_file;
    off_t where;

    if (how == 0)
        where = line;
    else
        if (dot == zero - 1)
            where = how * line;
        else
            where = how * line + dot->l_no;

    /* now, where is either at, before, or after dol */
    /* most likely case is after, so do it first */

    eoflag = 0;
    if (where >= dol->l_no) {
        if (doliseof) {
            dot = dol;
            eoflag++;
            return (EOF);
        }
        if (pipe_in)
            in_file = f = stdin;
        else
            (void) fseeko(f, (off_t)dol->l_addr, SEEK_SET);
        dot = dol - 1;
        while ((nchars = getline(f)) != EOF) {
            dot++;
            newdol(f);
            if (where == dot->l_no || brk_hit)
                break;
        }
        if (nchars != EOF)
            return (dot->l_no);
        else { /* EOF */
            dot = dol;
            eoflag++;
            doliseof++;
            eofl_no = dol->l_no;
            return (EOF);
        }
    } else { /* where < dol->l_no */
        if (pipe_in) {
            (void) fflush(tmp_fou);
            in_file = f = tmp_fin;
        }
        if (where < zero->l_no) {
            (void) fseeko(f, (off_t)zero->l_addr, SEEK_SET);
            dot = zero - 1;
            return (BOF);
        } else {
            dot = zero + where - 1;
            (void) fseeko(f, (off_t)dot->l_addr, SEEK_SET);
            nchars = getline(f);
            return (dot->l_no);
        }
    }
}

static FILE *fileptr;
static int (*rdchar)();

static int
mrdchar()
{
    return (rdchar(fileptr));
}

/*
 * Get a logical line
 */

static off_t
getline(f)
FILE *f;
{
    char    *p;
    int column;
    static char multic[MB_LEN_MAX];
    static int savlength;
    wchar_t c;
    int length, width;

    if (pipe_in && f == stdin)
        rdchar = fgetputc;
    else
        rdchar = (int (*)())fgetwc;

    fileptr = f;
    /* copy overlap from previous call to getline */
    if (savlength)
        (void) strncpy(Line, multic, (size_t)savlength);
    for (column = 0, p = Line + savlength; ; ) {
        if ((c = mrdchar()) <= 0) {
            clearerr(f);
            if (p > Line) { /* last line doesn't have '\n', */
                *p++ = '\n';
                *p = '\0';  /* print it any way */
                return (column);
            }
            return (EOF);
        }
        length = wctomb(multic, c);
        if (length < 0) {
            length = -length;
            c = 0;
        }
        if ((width = wcwidth(c)) < 0)
            width = 0;
        if (column + width > columns && !fflag)
            break;

        if (p + length > &Line[LINSIZ - 2] && c != '\n')
            break;
        (void) strncpy(p, multic, (size_t)length);
        p += length;
        column += width;
        /* don't have any overlap here */
        length = 0;
        switch (c) {
        case '\t': /* just a guess */
            column = 1 + (column | 7);
            break;
        case '\b':
            if (column > 0)
                column--;
            break;
        case '\r':
            column = 0;
            break;
        }
        if (c == '\n')
            break;
        if (column >= columns && !fflag)
            break;
    }
    if (c != '\n') { /* We're stopping in the middle of the line */
        if (column != columns || !auto_right_margin)
            *p++ = '\n';    /* for the display */
        /* save overlap for next call to getline */
        savlength = length;
        if (savlength == 0) {
            /*
             * check if following byte is newline and get
             * it if it is
             */
            c = fgetwc(f);
            if (c == '\n') {
                /* gobble and copy (if necessary) newline */
                (void) ungetwc(c, f);
                (void) (*rdchar)(f);
            } else if (c == EOF)
                clearerr(f);
            else
                (void) ungetwc(c, f);
        }
    } else
        savlength = 0;
    *p = 0;
    return (column);
}

static void
save_input(f)
FILE *f;
{
    if (pipe_in) {
        save_pipe();
        in_file = tmp_fin;
        pipe_in = 0;
    }
    (void) fseeko(in_file, (off_t)0, SEEK_SET);
    copy_file(in_file, f);
}

static void
save_pipe()
{
    if (!doliseof)
        while (fgetputc(stdin) != EOF)
            if (brk_hit) {
                brk_hit = 0;
                error("Piped input only partially saved");
                break;
            }
    (void) fclose(tmp_fou);
}

static int
fgetputc(f) /* copy anything read from a pipe to tmp_fou */
FILE *f;
{
    int c;

    if ((c = fgetwc(f)) != EOF)
        (void) fputwc(c, tmp_fou);
    return (c);
}

static  void
lineset(how)    /* initialize line memory */
int how;
{
    if (zero == NULL) {
        nlall = 128;
        zero = (LINE *) malloc(nlall * sizeof (LINE));
    }
    dol = contig = zero;
    zero->l_no = 1;
    zero->l_addr = 0l;
    if (how == BOF) {
        dot = zero - 1;
        eoflag = 0;
        doliseof = 0;
        eofl_no = -1;
    } else {
        dot = dol;
        eoflag = 1;
        doliseof = 1;
        eofl_no = 1;
    }
}

static void
newdol(f)   /* add address of new 'dol' */
        /* assumes that f is currently at beginning of said line */
        /* updates dol */
FILE *f;
{
    int diff;

    if ((dol - zero) + 1 >= nlall) {
        LINE *ozero = zero;

        nlall += 512;
        if ((zero = (LINE *)realloc((char *)zero,
            (unsigned)(nlall * sizeof (LINE)))) == NULL) {
            zero = ozero;
            compact();
        }
        diff = (int)((int)zero - (int)ozero);
        dot = (LINE *)((int)dot + diff);
        dol = (LINE *)((int)dol + diff);
        contig = (LINE *)((int)contig + diff);
    }
    dol++;
    if (!pipe_in)
        dol->l_addr = (off_t)ftello(f);
    else {
        (void) fflush(tmp_fou);
        dol->l_addr = (off_t)ftello(tmp_fou);
    }
    dol->l_no = (dol-1)->l_no + 1;
}

static void
compact()
{
    (void) perror("realloc");
    end_it();

}

static void
terminit()  /* set up terminal dependencies from termlib */
{
    int err_ret;
    struct termio ntty;

    for (;;) {
        gid_t my_tgid;
        my_tgid = (gid_t)tcgetpgrp(1);
        if (my_tgid < (gid_t)0 || my_tgid == my_pgid)
            break;
        (void) kill(-my_pgid, SIGTTOU);
    }

    if ((freopen("/dev/tty", "r+", stdout)) == NULL) {
        (void) perror("open");
        exit(1);
    }
    (void) ioctl(fileno(stdout), TCGETA, &otty);
    termflg = 1;

    (void) setupterm(0, fileno(stdout), &err_ret);
    (void) ioctl(fileno(stdout), TCGETA, &ntty);
    ntty.c_lflag &= ~(ECHONL | ECHO | ICANON);
    ntty.c_cc[VMIN] = 1;
    ntty.c_cc[VTIME] = 1;
    (void) ioctl(fileno(stdout), TCSETAW, &ntty);
    pg_stdin = fdopen(dup(fileno(stdout)), "r");
    (void) saveterm();
    (void) resetterm();
    if (lines <= 0 || hard_copy) {
        hard_copy = 1;
        lines = 24;
    }
    if (columns <= 0)
        columns = 80;
    if (clropt && !clear_screen)
        clropt = 0;
    if ((shell = getenv("SHELL")) == (char *)NULL)
            shell = "/usr/bin/sh";
}

static void
error(mess)
char *mess;
{
    kill_line();
    sopr(gettext(mess), 1);
    prompt((char *)NULL);
    errors++;
}

static void
prompt(filename)
char *filename;
{
    char outstr[PROMPTSIZE+6];
    int pagenum;
    if (filename != NULL) {
        /*
         * TRANSLATION_NOTE
         *  %s is a filename.
         */
        (void) sprintf(outstr, gettext("(Next file: %s)"), filename);
    } else {
        if ((pagenum = (int)((new_ss.last_line-2)/(window-1)+1))
                        > 999999)
            pagenum = 999999;
        (void) sprintf(outstr, promptstr, pagenum);
    }
    sopr(outstr, 1);
    (void) fflush(stdout);
}

/*
 *  sopr puts out the message (please no \n's) surrounded by standout
 *  begins and ends
 */

static void
sopr(m, count)
    char *m;
    int count;
{
    wchar_t wc;
    int len, n;
    char    *p;

    if (count) {
        p = m;
        for (; *p; p += len) {
            if ((len = mbtowc(&wc, p, MB_CUR_MAX)) <= 0) {
                len = 1;
                continue;
            }
            if ((n = wcwidth(wc)) > 0)
                promptlen += n;
        }
    }
    if (soflag && enter_standout_mode && exit_standout_mode) {
        (void) putp(enter_standout_mode);
        (void) fputs(m, stdout);
        (void) putp(exit_standout_mode);
    }
    else
        (void) fputs(m, stdout);
}

static void
doclear()
{
    if (clear_screen)
        (void) putp(clear_screen);
    (void) putchar('\r');  /* this resets the terminal drivers character */
            /* count in case it is trying to expand tabs  */

}

static void
kill_line()
{
    erase_line(0);
    if (!clr_eol) (void) putchar('\r');

}

/* erase from after col to end of prompt */
static void
erase_line(col)
int col;
{

    if (promptlen == 0)
        return;
    if (hard_copy)
        (void) putchar('\n');
    else {
        if (col == 0)
            (void) putchar('\r');
        if (clr_eol) {
            (void) putp(clr_eol);
            /* for the terminal driver again */
            (void) putchar('\r');
        }
        else
            for (col = promptlen - col; col > 0; col--)
                (void) putchar(' ');
    }
    promptlen = 0;
}

/*
 * Come here if a quit or interrupt signal is received
 */

static void
on_brk(sno)
    int sno;    /* signal number generated */
{
    (void) signal(sno, on_brk);
    if (!inwait) {
        BEEP();
        brk_hit = 1;
    } else {
        brk_hit = 0;
        longjmp(restore, 1);
    }
}

/*
 * Clean up terminal state and exit.
 */

void
end_it()
{

    if (out_is_tty) {
        kill_line();
        (void) resetterm();
        if (termflg)
            (void) ioctl(fileno(stdout), TCSETAW, &otty);
    }
    if (tmp_fin)
        (void) fclose(tmp_fin);
    if (tmp_fou)
        (void) fclose(tmp_fou);
    if (tmp_fou || tmp_fin)
        (void) unlink(tmp_name);
    exit(status);
}

void
onsusp()
{
    int ttou_is_dfl;

    /* ignore SIGTTOU so following resetterm and flush works */
    ttou_is_dfl = (signal(SIGTTOU, SIG_IGN) == SIG_DFL);
    (void) resetterm();
    (void) fflush(stdout);
    if (ttou_is_dfl)
        (void) signal(SIGTTOU, SIG_DFL);

    /* send SIGTSTP to stop this process group */
    (void) signal(SIGTSTP, SIG_DFL);
    (void) kill(-my_pgid, SIGTSTP);

    /* continued - reset the terminal */
#ifdef __STDC__
    (void) signal(SIGTSTP, (void (*)(int))onsusp);
#else
    (void) signal(SIGTSTP, (void (*))onsusp);
#endif
    (void) resetterm();
    if (inwait)
        longjmp(restore, -1);

}

static char *
pg_strchr(str, c)
char    *str;
wchar_t c;
{
    while (*str) {
        if (c == *str)
            return (str);
        str++;
    }
    return (0);
}

void
usage()
{
    (void) fprintf(stderr, gettext(
"Usage: pg [-number] [-p string] [-cefnrs] [+line] [+/pattern/] files\n"));
    exit(1);
}