new version from Kevin Fall -- only lightly tested!

[unix-history] / usr / src / bin / cat / cat.c

/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kevin Fall.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1989 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)cat.c       5.4 (Berkeley) %G%";
#endif /* not lint */

#include <stdio.h>
#include <ctype.h>

int bflag, eflag, nflag, sflag, tflag, vflag;
int rval;
char *filename;

main(argc, argv)
       int argc;
       char **argv;
{
       extern int errno, optind;
       register FILE *fp;
       int ch;
       char *strerror();

       while ((ch = getopt(argc, argv, "-benstuv")) != EOF)
               switch (ch) {
               case '-':
                       --optind;
                       goto done;
               case 'b':
                       bflag = nflag = 1;      /* -b implies -n */
                       break;
               case 'e':
                       eflag = vflag = 1;      /* -e implies -v */
                       break;
               case 'n':
                       nflag = 1;
                       break;
               case 's':
                       sflag = 1;
                       break;
               case 't':
                       tflag = vflag = 1;      /* -t implies -v */
                       break;
               case 'u':
                       setbuf(stdout, (char *)NULL);
                       break;
               case 'v':
                       vflag = 1;
                       break;
               case '?':
                       (void)fprintf(stderr,
                           "usage: cat [-benstuv] [-] [file ...]\n");
                       exit(1);
               }
done:   argv += optind;

       fp = stdin;
       filename = "-";
       do {
               if (*argv) {
                       if (!strcmp(*argv, "-")) {
                               fp = stdin;
                               filename = "-";
                       }
                       else if (!(fp = fopen(filename = *argv, "r"))) {
                               (void)fprintf(stderr, 
                                   "cat: %s: %s\n", *argv, strerror(errno));
                               ++argv;
                               continue;
                       }
                       ++argv;
               }
               if (bflag || eflag || nflag || sflag || tflag || vflag)
                       process_buf(fp);
               else
                       rawcat(fileno(fp));
               if (fp != stdin)
                       (void)fclose(fp);
       } while (*argv);
       exit(rval);
}

process_buf(fp)
       register FILE *fp;
{
       register int ch, gobble, line, prev;

       line = gobble = 0;
       for (prev = '\n'; (ch = getc(fp)) != EOF; prev = ch) {
               if (prev == '\n') {
                       if (ch == '\n') {
                               if (sflag) {
                                       if (gobble)
                                               continue;
                                       gobble = 1;
                               }
                               if (nflag && !bflag) {
                                       (void)fprintf(stdout, "%6d\t", ++line);
                                       if (ferror(stdout))
                                               break;
                               }
                       }
                       else if (nflag) {
                               (void)fprintf(stdout, "%6d\t", ++line);
                               if (ferror(stdout))
                                       break;
                       }
               }
               if (ch == '\n') {
                       if (eflag)
                               if (putc('$', stdout) == EOF)
                                       break;
               } else if (ch == '\t') {
                       if (tflag) {
                               if (putc('^', stdout) == EOF ||
                                   putc('I', stdout) == EOF)
                                       break;
                               continue;
                       }
               } else if (vflag) {
                       if (ch > 0177) {
                               if (putc('M', stdout) == EOF ||
                                   putc('-', stdout) == EOF)
                                       break;
                               ch &= 0177;
                       }
                       if (iscntrl(ch)) {
                               if (putc('^', stdout) == EOF ||
                                   putc(ch == '\177' ? '?' :
                                   ch | 0100, stdout) == EOF)
                                       break;
                               continue;
                       }
               }
               if (putc(ch, stdout) == EOF)
                       break;
       }
       if (ferror(fp)) {
               (void)fprintf(stderr, "cat: %s: read error\n", filename);
               rval = 1;
       }
       if (ferror(stdout)) {
               clearerr(stdout);
               (void)fprintf(stderr, "cat: stdout: write error\n");
               rval = 1;
       }
}

rawcat(fd)
       register int fd;
{
       extern int errno;
       static char buf[8*1024];
       register int nr, nw, off;
       char *strerror();

       while ((nr = read(fd, buf, sizeof(buf))) > 0)
               for (off = 0; off < nr;) {
                       if ((nw = write(fileno(stdout), buf + off, nr)) < 0) {
                               perror("cat: stdout");
                               rval = 1;
                               return;
                       }
                       off += nw;
               }
       if (nr < 0) {
               (void)fprintf(stderr, "cat: %s: %s\n", filename,
                   strerror(errno));
               rval = 1;
       }
}