BSD 4 release

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

static char *sccsid = "@(#)tr.c 4.1 (Berkeley) 10/1/80";
#include <stdio.h>

/* tr - transliterate data stream */
int     dflag   = 0;
int     sflag   = 0;
int     cflag = 0;
int     save    = 0;
char    code[256];
char    squeez[256];
char    vect[256];
struct string { int last, max; char *p; } string1, string2;

main(argc,argv)
char **argv;
{
       register i;
       int j;
       register c, d;
       char *compl;
       int lastd;

       string1.last = string2.last = 0;
       string1.max = string2.max = 0;
       string1.p = string2.p = "";

       if(--argc>0) {
               argv++;
               if(*argv[0]=='-'&&argv[0][1]!=0) {
                       while(*++argv[0])
                               switch(*argv[0]) {
                               case 'c':
                                       cflag++;
                                       continue;
                               case 'd':
                                       dflag++;
                                       continue;
                               case 's':
                                       sflag++;
                                       continue;
                               }
                       argc--;
                       argv++;
               }
       }
       if(argc>0) string1.p = argv[0];
       if(argc>1) string2.p = argv[1];
       for(i=0; i<256; i++)
               code[i] = vect[i] = 0;
       if(cflag) {
               while(c = next(&string1))
                       vect[c&0377] = 1;
               j = 0;
               for(i=1; i<256; i++)
                       if(vect[i]==0) vect[j++] = i;
               vect[j] = 0;
               compl = vect;
       }
       for(i=0; i<256; i++)
               squeez[i] = 0;
       lastd = 0;
       for(;;){
               if(cflag) c = *compl++;
               else c = next(&string1);
               if(c==0) break;
               d = next(&string2);
               if(d==0) d = lastd;
               else lastd = d;
               squeez[d&0377] = 1;
               code[c&0377] = dflag?1:d;
       }
       while(d = next(&string2))
               squeez[d&0377] = 1;
       squeez[0] = 1;
       for(i=0;i<256;i++) {
               if(code[i]==0) code[i] = i;
               else if(dflag) code[i] = 0;
       }

       while((c=getc(stdin)) != EOF ) {
               if(c == 0) continue;
               if(c = code[c&0377]&0377)
                       if(!sflag || c!=save || !squeez[c&0377])
                               putchar(save = c);
       }
       exit(0);
}

next(s)
struct string *s;
{

again:
       if(s->max) {
               if(s->last++ < s->max)
                       return(s->last);
               s->max = s->last = 0;
       }
       if(s->last && *s->p=='-') {
               nextc(s);
               s->max = nextc(s);
               if(s->max==0) {
                       s->p--;
                       return('-');
               }
               if(s->max < s->last)  {
                       s->last = s->max-1;
                       return('-');
               }
               goto again;
       }
       return(s->last = nextc(s));
}

nextc(s)
struct string *s;
{
       register c, i, n;

       c = *s->p++;
       if(c=='\\') {
               i = n = 0;
               while(i<3 && (c = *s->p)>='0' && c<='7') {
                       n = n*8 + c - '0';
                       i++;
                       s->p++;
               }
               if(i>0) c = n;
               else c = *s->p++;
       }
       if(c==0) *--s->p = 0;
       return(c&0377);
}