BSD 3 release

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

/*
*
* ul - General underline filter. Converts underlines by
* the standard backspacing method to the code used by the
* particular terminal to underline.
*
*/
#include <stdio.h>
char buf[BUFSIZ];
char isul[BUFSIZ];
char termcap[1024];
char ulbuf[BUFSIZ];
char *stul, *endul, *chul;
char *backspace;
char *termtype;
int outc();
char *tgetstr();
char *getenv();

main(argc,argv) char **argv; {
       register int i;
       char *cp;
       FILE *f;

       /* Figure out kind of terminal and set up special strings. */
       termtype = getenv("TERM");
       if (termtype == NULL)
               termtype = "dumb";
       while (argc >= 2 && argv[1][0] == '-') {
               switch(argv[1][1]) {
               case 't':
               case 'T': /* for nroff compatibility */
                       if (argv[1][2])
                               termtype = &argv[1][2];
                       else {
                               termtype = argv[2];
                               argc--;
                               argv++;
                       }
                       break;
               default:
                       printf("Bad switch: %s\n",argv[1]);
                       exit(1);
               }
       }
       switch(tgetent(termcap, termtype)) {
               case 1: /* All is well */
                       /* Terminals that don't need any help. */
                       if (tgetflag("ul") || tgetflag("os"))
                               execv("/bin/cat",argv);
                       cp = ulbuf;
                       if ((backspace = tgetstr("bc",&cp)) == NULL)
                               backspace = "\b";
                       /*
                        * Handle terminals that have start underline/stop
                        * underline sequences, as well as those with
                        * underline char sequences (we assume the sequence
                        * moves the cursor forward one character).
                        * If we can't find underline sequences, we
                        * settle for standout sequences.
                        */
                       if (    (chul=tgetstr("uc",&cp)) == NULL)
                                       chul = "";
                       if (    (stul=tgetstr("us",&cp)) == NULL &&
                               (!*chul) && (stul=tgetstr("so",&cp)) == NULL)
                                       stul = "";
                       if (    (endul=tgetstr("ue",&cp)) == NULL &&
                               (!*chul) && (endul=tgetstr("se",&cp)) == NULL)
                                       endul = "";
                       break;
               default:/* error opening/reading termcap */
                       fprintf(stderr,"trouble reading termcap");
                       /* fall through to ... */
               case 0: /* No such terminal type - assume dumb */
                       stul = endul = chul = "";
                       break;
       }
       if (argc < 2) filter(stdin);
       else for (i=1; i<argc; i++) {
               f = fopen(argv[i],"r");
               if (f == NULL) {
                       printf("Can't open %s\n",argv[i]);
                       exit(1);
               } else filter(f);
       }
       exit(0);
}

filter(f)
FILE *f;
{
       register int p, n;
       register char c;
       int state;

       n = 0;
       for (;;) {
               p = 0;
               for (p=0; p<n; p++) {
                       buf[p] = '\0';
                       isul[p] = 0;
               }
               p = n = 0;

               for (;;) {
                       c = getc(f);
                       if (c==EOF) break;
                       if (c=='\b') {
                               if (p > 0) {
                                       p--;
                               }
                       } else if (c=='_' && isul[p]==0 && buf[p]) {
                               isul[p] = 1;
                               p++;
                       } else {
                               if (buf[p] == '_') {
                                       isul[p] = 1;
                               }
                               buf[p] = c;
                               p++;
                               if (n < p) n = p;
                       }
                       if (c=='\n') break;
               }

               state = 0;
               for (p=0; p<n; p++) {
                       if (isul[p] != state)
                               tputs(isul[p] ? stul : endul, 1, outc);
                       state = isul[p];
                       outc(buf[p]);
                       if (isul[p] && *chul) {
                               printf("%s",backspace);
                               tputs(chul, 1, outc);
                       }
               }
               if (c==EOF) break;
       }
}

outc(c)
char c;
{
       putchar(c);
}