BSD 4 release

[unix-history] / usr / src / cmd / unexpand.c

static char *sccsid = "@(#)unexpand.c   4.1 (Berkeley) 10/1/80";
/*
* unexpand - put tabs into a file replacing blanks
*/
#include <stdio.h>

char    genbuf[BUFSIZ];
char    linebuf[BUFSIZ];
int     all;

main(argc, argv)
       int argc;
       char *argv[];
{
       register char *cp;

       argc--, argv++;
       if (argv[0][0] == '-') {
               if (strcmp(argv[0], "-a") != 0) {
                       fprintf(stderr, "usage: unexpand [ -a ] file ...\n");
                       exit(1);
               }
               all++;
               argc--, argv++;
       }
       do {
               if (argc > 0) {
                       if (freopen(argv[0], "r", stdin) == NULL) {
                               perror(argv[0]);
                               exit(1);
                       }
                       argc--, argv++;
               }
               while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
                       for (cp = linebuf; *cp; cp++)
                               continue;
                       if (cp > linebuf)
                               cp[-1] = 0;
                       tabify(all);
                       printf("%s", linebuf);
               }
       } while (argc > 0);
       exit(0);
}

tabify(c)
       char c;
{
       register char *cp, *dp;
       register int dcol;
       int ocol;

       ocol = 0;
       dcol = 0;
       cp = genbuf, dp = linebuf;
       for (;;) {
               switch (*cp) {

               case ' ':
                       dcol++;
                       break;

               case '\t':
                       dcol =+ 8;
                       dcol =& ~07;
                       break;

               default:
                       while (((ocol + 8) &~ 07) <= dcol) {
                               if (ocol + 1 == dcol)
                                       break;
                               *dp++ = '\t';
                               ocol =+ 8;
                               ocol =& ~07;
                       }
                       while (ocol < dcol) {
                               *dp++ = ' ';
                               ocol++;
                       }
                       if (*cp == 0 || c == 0) {
                               strcpy(dp, cp);
                               return;
                       }
                       *dp++ = *cp;
                       ocol++, dcol++;
               }
               cp++;
       }
}