cmd/sdiff/sdiff.c

/*
 * 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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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


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

    /*
     *  sdiff [-l] [-s] [-w #] [-o output] file1 file2
     *  does side by side diff listing
     *  -l leftside only for identical lines
     *  -s silent; only print differences
     *  -w # width of output
     *  -o output  interactive creation of new output commands:
     *      s   silent; do not print identical lines
     *      v   turn off silent
     *      l   copy left side to output
     *      r   copy right side to output
     *      e l call ed with left side
     *      e r call ed with right side
     *      e b call ed with cat of left and right
     *      e   call ed with empty file
     *      q   exit from program
     *
     *  functions:
     *  cmd decode diff commands
     *  put1    output left side
     *  put2    output right side
     *  putmid  output gutter
     *  putline output n chars to indicated file
     *  getlen  calculate length of strings with tabs
     *  cmdin   read and process interactive cmds
     *  cpp copy from file to file
     *  edit    call ed with file
     */

#include <stdio.h>
#include <ctype.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#include <locale.h>
#include <limits.h>
#include <string.h>
#include <wchar.h>

#define LMAX    BUFSIZ
#define BMAX    BUFSIZ
#define STDOUT  1
#define WGUTTER 6
#define WLEN    (WGUTTER * 2 + WGUTTER + 2)
#define PROMPT  '%'

static const char   twoblanks[3] = "  ";

static const char   *DIFF   = "diff -b ";
static char diffcmd[BMAX];
static char inbuf[10];

static int  llen = 130; /* Default maximum line length written out */
static int  hlen;       /* Half line length with space for gutter */
static int  len1;       /* Calculated length of left side */
static int  nchars;     /* Number of characters in left side - */
                    /* used for tab expansion */
static char change = ' ';
static int  leftonly = 0;   /* if set print left side only for */
                    /* identical lines */
static int  silent = 0; /* if set do not print identical lines */
static int  midflg = 0; /* set after middle was output */
static int  rcode = 0;  /* return code */


static char *file1;
static FILE *fdes1;

static char *file2;
static FILE *fdes2;

static FILE *diffdes;

static int oflag;
static char *ofile;
static FILE *odes;

static char *ltemp;
static FILE *left;

static char *rtemp;
static FILE *right;

static FILE *tempdes;
static char *temp;

/* decoded diff cmd- left side from to; right side from, to */

static int from1, to1, from2, to2;

static int num1, num2;      /* line count for left side file and right */
static int tempfd = -1;

static char *filename(char *, char *);
static char *fgetline(FILE *);
static int  put1(void);
static int  put2(void);
static void putline(FILE *, char *, int);
static int  cmd(char *);
static int  getlen(int, char *);
static void putmid(int);
static void error(char *, char *);
static void onintr(void);
static void sremove(void);
static void cmdin(void);
static void cpp(char *, FILE *, FILE *);
static void edit(char *);

int
main(int argc, char **argv)
{
    int com;
    int n1, n2, n;
    char    *bp;
    int lfd = -1;
    int rfd = -1;

    if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
        (void) signal((int)SIGHUP, (void (*)(int))onintr);
    if (signal(SIGINT, SIG_IGN) != SIG_IGN)
        (void) signal((int)SIGINT, (void (*)(int))onintr);
    if (signal(SIGPIPE, SIG_IGN) != SIG_IGN)
        (void) signal((int)SIGPIPE, (void (*)(int))onintr);
    if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
        (void) signal((int)SIGTERM, (void (*)(int))onintr);

    (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif
    (void) textdomain(TEXT_DOMAIN);

    while (--argc > 1 && **++argv == '-') {
        switch (*++*argv) {

        case 'w':
            /* -w# instead of -w # */
            if (*++*argv)
                llen = atoi(*argv);
            else {
                argc--;
                llen = atoi(*++argv);
            }
            if (llen < WLEN)
                error(gettext("Wrong line length %s"), *argv);
            if (llen > LMAX)
                llen = LMAX;
            break;

        case 'l':
            leftonly++;
            break;

        case 's':
            silent++;
            break;
        case 'o':
            oflag++;
            argc--;
            ofile = *++argv;
            break;
        default:
            error(gettext("Illegal argument: %s"), *argv);
        }
    }
    if (argc != 2) {
        (void) fprintf(stderr, gettext(
        "Usage: sdiff [-l] [-s] [-o output] [-w #] file1 file2\n"));
        return (2);
    }

    file1 = *argv++;
    file2 = *argv;
    file1 = filename(file1, file2);
    file2 = filename(file2, file1);
    hlen = (llen - WGUTTER +1)/2;

    if ((fdes1 = fopen(file1, "r")) == NULL)
        error(gettext("Cannot open: %s"), file1);

    if ((fdes2 = fopen(file2, "r")) == NULL)
        error(gettext("Cannot open: %s"), file2);

    if (oflag) {
        if (tempfd == -1) {
            temp = strdup("/tmp/sdiffXXXXXX");
            tempfd = mkstemp(temp);
            if (tempfd == -1) {
                error(gettext(
                    "Cannot open/create temp %s"), temp);
                free(temp);
                temp = 0;
            }
        }
        ltemp = strdup("/tmp/sdifflXXXXXX");
        if ((lfd = mkstemp(ltemp)) == -1 ||
            (left = fdopen(lfd, "w")) == NULL)
                error(gettext(
                    "Cannot open/create temp %s"),
                    ltemp);
        rtemp = strdup("/tmp/sdiffrXXXXXX");
        if ((rfd = mkstemp(rtemp)) == -1 ||
            (right = fdopen(rfd, "w")) == NULL)
                error(gettext(
                    "Cannot open/create temp file %s"),
                    rtemp);
        if ((odes = fopen(ofile, "w")) == NULL)
            error(gettext("Cannot open output %s"), ofile);
    }
    /* Call DIFF command */
    (void) strcpy(diffcmd, DIFF);
    (void) strcat(diffcmd, file1);
    (void) strcat(diffcmd, " ");
    (void) strcat(diffcmd, file2);
    diffdes = popen(diffcmd, "r");

    num1 = num2 = 0;

    /*
     * Read in diff output and decode commands
     * "change" is used to determine character to put in gutter
     *  num1 and num2 counts the number of lines in file1 and 2
     */

    n = 0;
    while ((bp = fgetline(diffdes)) != NULL) {
        change = ' ';
        com = cmd(bp);

    /*
     * handles all diff output that is not cmd
     * lines starting with <, >, ., ---
     */
        if (com == 0)
            continue;

    /* Catch up to from1 and from2 */
        rcode = 1;
        n1 = from1 - num1;
        n2 = from2 - num2;
        n = n1 > n2 ? n2 : n1;
        if (com == 'c' && n > 0)
            n--;
        if (silent)
            (void) fputs(bp, stdout);
        while (n-- > 0) {
            (void) put1();
            (void) put2();
            if (!silent)
                (void) putc('\n', stdout);
            midflg = 0;
        }

    /* Process diff cmd */
        switch (com) {

        case 'a':
            change = '>';
            while (num2 < to2) {
                (void) put2();
                (void) putc('\n', stdout);
                midflg = 0;
            }
            break;

        case 'd':
            change = '<';
            while (num1 < to1) {
                (void) put1();
                (void) putc('\n', stdout);
                midflg = 0;
            }
            break;

        case 'c':
            n1 = to1 - from1;
            n2 = to2 - from2;
            n = n1 > n2 ? n2 : n1;
            change = '|';
            do {
                (void) put1();
                (void) put2();
                (void) putc('\n', stdout);
                midflg = 0;
            } while (n--);

            change = '<';
            while (num1 < to1) {
                (void) put1();
                (void) putc('\n', stdout);
                midflg = 0;
            }

            change = '>';
            while (num2 < to2) {
                (void) put2();
                (void) putc('\n', stdout);
                midflg = 0;
            }
            break;

        default:
            (void) fprintf(stderr, gettext(
                "%c: cmd not found\n"), cmd);
            break;
        }

        if (oflag == 1 && com != 0) {
            cmdin();
            if ((left = fopen(ltemp, "w")) == NULL)
                error(gettext(
                    "main: Cannot open temp %s"), ltemp);
            if ((right = fopen(rtemp, "w")) == NULL)
                error(gettext(
                    "main: Cannot open temp %s"), rtemp);
        }
    }
    /* put out remainder of input files */

    while (put1()) {
        (void) put2();
        if (!silent)
            (void) putc('\n', stdout);
        midflg = 0;
    }
    if (odes)
        (void) fclose(odes);
    sremove();
    return (rcode);
}

static int
put1(void)
{
    /* len1 = length of left side */
    /* nchars = num of chars including tabs */

    char    *bp;


    if ((bp = fgetline(fdes1)) != NULL) {
        len1 = getlen(0, bp);
        if ((!silent || change != ' ') && len1 != 0)
            putline(stdout, bp, nchars);

        if (oflag) {
        /*
         * put left side either to output file
         * if identical to right
         * or left temp file if not
         */

            if (change == ' ')
                putline(odes, bp, strlen(bp));
            else
                putline(left, bp, strlen(bp));
        }
        if (change != ' ')
            putmid(1);
        num1++;
        return (1);
    } else
        return (0);
}

static int
put2(void)
{
    char    *bp;

    if ((bp = fgetline(fdes2)) != NULL) {
        (void) getlen((hlen + WGUTTER) % 8, bp);

        /*
         * if the left and right are different they are always
         * printed.
         * If the left and right are identical
         * right is only printed if leftonly is not specified
         * or silent mode is not specified
         * or the right contains other than white space (len1 !=0)
         */
        if (change != ' ') {

        /*
         * put right side to right temp file only
         * because left side was written to output for
         * identical lines
         */

            if (oflag)
                putline(right, bp, strlen(bp));

            if (midflg == 0)
                putmid(1);
            putline(stdout, bp, nchars);
        } else
            if (!silent && !leftonly && len1 != 0) {
                if (midflg == 0)
                    putmid(1);
                putline(stdout, bp, nchars);
            }
        num2++;
        len1 = 0;
        return (1);
    } else {
        len1 = 0;
        return (0);
    }
}

static void
putline(FILE *file, char *start, int num)
{
    char    *cp, *end;
    int i, len, d_col;
    wchar_t wc;

    cp = start;
    end = cp + num;
    while (cp < end) {
        if (isascii(*cp)) {
            (void) putc(*cp++, file);
            continue;
        }

        if ((len = end - cp) > MB_LEN_MAX)
            len = MB_LEN_MAX;

        if ((len = mbtowc(&wc, cp, len)) <= 0) {
            (void) putc(*cp++, file);
            continue;
        }

        if ((d_col = wcwidth(wc)) <= 0)
            d_col = len;

        if ((cp + d_col) > end)
            return;

        for (i = 0; i < len; i++)
            (void) putc(*cp++, file);
    }
}

static int
cmd(char *start)
{
    unsigned char   *cp;
    char    *cps;
    int com;

    if (*start == '>' || *start == '<' || *start == '-' || *start == '.')
        return (0);

    cp = (unsigned char *)start;
    cps = start;
    while (isdigit(*cp))
        cp++;
    from1 = atoi(cps);
    to1 = from1;
    if (*cp == ',') {
        cp++;
        cps = (char *)cp;
        while (isdigit(*cp))
            cp++;
        to1 = atoi(cps);
    }

    com = *cp++;
    cps = (char *)cp;

    while (isdigit(*cp))
        cp++;
    from2 = atoi(cps);
    to2 = from2;
    if (*cp == ',') {
        cp++;
        cps = (char *)cp;
        while (isdigit(*cp))
            cp++;
        to2 = atoi(cps);
    }
    return (com);
}

static int
getlen(int startpos, char *buffer)
{
    /*
     * get the length of the string in buffer
     *  expand tabs to next multiple of 8
     */
    unsigned char   *cp;
    int slen, tlen, len, d_col;
    int notspace;
    wchar_t wc;

    nchars = 0;
    notspace = 0;
    tlen = startpos;
    for (cp = (unsigned char *)buffer; (*cp != '\n') && (*cp); cp++) {
        if (*cp == '\t') {
            slen = tlen;
            tlen += 8 - (tlen % 8);
            if (tlen >= hlen) {
                tlen = slen;
                break;
            }
            nchars++;
            continue;
        }

        if (isascii(*cp)) {
            slen = tlen;
            tlen++;
            if (tlen >= hlen) {
                tlen = slen;
                break;
            }
            if (!isspace(*cp))
                notspace = 1;
            nchars++;
            continue;
        }

        if ((len = mbtowc(&wc, (char *)cp, MB_LEN_MAX)) <= 0) {
            slen = tlen;
            tlen++;
            if (tlen >= hlen) {
                tlen = slen;
                break;
            }
            notspace = 1;
            nchars++;
            continue;
        }

        if ((d_col = wcwidth(wc)) <= 0)
            d_col = len;

        slen = tlen;
        tlen += d_col;
        if (tlen > hlen) {
            tlen = slen;
            break;
        }
        notspace = 1;
        cp += len - 1;
        nchars += len;
    }
    return (notspace ? tlen : 0);
}

static void
putmid(int bflag)
{
    int i;

    /*
     * len1 set by getlen to the possibly truncated
     *  length of left side
     *  hlen is length of half line
     */

    midflg = 1;
    if (bflag) {
        for (i = 0; i < hlen - len1; i++)
            (void) putc(' ', stdout);
    }
    (void) fputs(twoblanks, stdout);
    (void) putc((int)change, stdout);
    (void) fputs(twoblanks, stdout);
}

static void
error(char *s1, char *s2)
{
    (void) fprintf(stderr, "sdiff: ");
    (void) fprintf(stderr, s1, s2);
    (void) putc('\n', stderr);
    sremove();
    exit(2);
}

static void
onintr(void)
{
    sremove();
    exit(rcode);
}

static void
sremove(void)
{
    if (ltemp) {
        (void) unlink(ltemp);
        free(ltemp);
    }
    if (rtemp) {
        (void) unlink(rtemp);
        free(rtemp);
    }
    if (temp) {
        (void) unlink(temp);
        free(temp);
    }
}

static void
cmdin(void)
{
    char    *cp, *ename;
    int notacc;

    (void) fclose(left);
    (void) fclose(right);
    notacc = 1;
    while (notacc) {
        (void) putc(PROMPT, stdout);
        if ((cp = fgets(inbuf, 10, stdin)) == NULL) {
            (void) putc('\n', stdout);
            break;
        }
        switch (*cp) {

        case 's':
            silent = 1;
            break;

        case 'v':
            silent = 0;
            break;

        case 'q':
            sremove();
            exit(rcode);
            /* NOTREACHED */
            break;

        case 'l':
            cpp(ltemp, left, odes);
            notacc = 0;
            break;

        case 'r':
            cpp(rtemp, right, odes);
            notacc = 0;
            break;

        case 'e':
            while (*++cp == ' ')
                ;
            switch (*cp) {
            case 'l':
            case '<':
                notacc = 0;
                ename = ltemp;
                edit(ename);
                break;

            case 'r':
            case '>':
                notacc = 0;
                ename = rtemp;
                edit(ename);
                break;

            case 'b':
            case '|':
                if ((tempdes = fopen(temp, "w")) == NULL)
                    error(gettext(
                        "Cannot open temp file %s"),
                        temp);
                cpp(ltemp, left, tempdes);
                cpp(rtemp, right, tempdes);
                (void) fclose(tempdes);
                notacc = 0;
                ename = temp;
                edit(ename);
                break;

            case '\n':
                if ((tempdes = fopen(temp, "w")) == NULL)
                    error(gettext(
                        "Cannot open temp file %s"),
                        temp);
                (void) fclose(tempdes);
                notacc = 0;
                ename = temp;
                edit(ename);
                break;
            default:
                (void) fprintf(stderr, gettext(
                    "Illegal command %s reenter\n"),
                    cp);
                break;
            }
            if (notacc == 0)
                cpp(ename, tempdes, odes);
            break;

        default:
            (void) fprintf(stderr, gettext(
                "Illegal command reenter\n"));
            break;
        }
    }
}

static void
cpp(char *from, FILE *fromdes, FILE *todes)
{
    char    tempbuf[BMAX + 1];

    if ((fromdes = fopen(from, "r")) == NULL)
        error(gettext(
            "cpp: Cannot open %s"), from);
    while ((fgets(tempbuf, BMAX, fromdes) != NULL))
        (void) fputs(tempbuf, todes);
    (void) fclose(fromdes);
}

static void
edit(char *file)
{
    int i;
    pid_t   pid;
    void (*oldintr)(int);

    switch (pid = fork()) {
    case (pid_t)-1:
        error(gettext("Cannot fork"), NULL);
        /* NOTREACHED */
        break;
    case (pid_t)0:
        (void) execl("/usr/bin/ed", "ed", file, NULL);
    }

    oldintr = signal(SIGINT, SIG_IGN);  /* ignore interrupts in ed */
    while (pid != wait(&i))
        ;
    /* restore previous interrupt proc */
    (void) signal(SIGINT, oldintr);
}

static char *
filename(char *pa1, char *pa2)
{
    int c;
    char    *a1, *b1, *a2;
    struct stat stbuf;
    a1 = pa1;
    a2 = pa2;
    if (stat(a1, &stbuf) != -1 && ((stbuf.st_mode&S_IFMT) == S_IFDIR)) {
        b1 = pa1 = (char *)malloc(strlen(a1) + strlen(a2) + 2);
        while (*b1++ = *a1++);
        b1[-1] = '/';
        a1 = b1;
        while (*a1++ = *a2++)
            if (*a2 && *a2 != '/' && a2[-1] == '/')
                a1 = b1;
    } else if (a1[0] == '-' && a1[1] == 0 && temp == 0) {
        if (fstat(fileno(stdin), &stbuf) == -1)
            error(gettext("Cannot process stdin"), NULL);
        pa1 = temp = strdup("/tmp/sdiffXXXXXX");
        if ((tempfd = mkstemp(temp)) == -1 ||
            (tempdes = fdopen(tempfd, "w")) == NULL)
                error(gettext("Cannot open/create temp %s"),
                    temp);
        while ((c = getc(stdin)) != EOF)
            (void) putc(c, tempdes);
        (void) fclose(tempdes);
    }
    return (pa1);
}

/*
 * like fgets, but reads upto and including a newline,
 * the data is stored in a reusable dynamic buffer that grows to fit
 * the largest line in the file, the buffer is NULL terminated
 * returns a pointer to the dynamic buffer.
 */
static char *
fgetline(FILE *fp)
{
    static char *bp = NULL;
    static int  blen = 0;
    int sl;

    if (bp == NULL) {
        /* allocate it for the first time */
        bp = (char *)malloc(BUFSIZ);
        if (bp == NULL)
            error(gettext("fgetline: malloc failed"), NULL);
        blen = BUFSIZ;
    }

    /* check for error or nothing read */
    if (fgets(bp, blen, fp) == NULL)
        return (NULL);

    if (feof(fp))
        return (bp);

    while ((sl = strlen(bp)) == blen-1 && *(bp+blen-2) != '\n') {
        /* still more data, grow the buffer */
        blen *= 2;
        bp = (char *)realloc(bp, blen);
        if (bp == NULL)
            error(gettext("fgetline: realloc failed"), NULL);
        /* continue reading and add to end of buffer */
        (void) fgets(bp+sl, blen-sl, fp);
    }
    return (bp);
}