Add include files to get prototype declarations, and fix bugs found.

[unix-history] / usr / src / lib / libc / gen / vis.c

/*-
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)vis.c       5.4 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <ctype.h>
#include <vis.h>

#define isoctal(c)      (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')

/*
* vis - visually encode characters
*/
char *
#if __STDC__
vis(register char *dst, register char c, register int flag, char nextc)
#else
vis(dst, c, flag, nextc)
       register char *dst, c;
       char nextc;
       register int flag;
#endif
{
       if (isascii(c) && isgraph(c) ||
          ((flag & VIS_SP) == 0 && c == ' ') ||
          ((flag & VIS_TAB) == 0 && c == '\t') ||
          ((flag & VIS_NL) == 0 && c == '\n') ||
          ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
               *dst++ = c;
               if (c == '\\' && (flag & VIS_NOSLASH) == 0)
                       *dst++ = '\\';
               *dst = '\0';
               return (dst);
       }

       if (flag & VIS_CSTYLE) {
               switch(c) {
               case '\n':
                       *dst++ = '\\';
                       *dst++ = 'n';
                       goto done;
               case '\r':
                       *dst++ = '\\';
                       *dst++ = 'r';
                       goto done;
               case '\b':
                       *dst++ = '\\';
                       *dst++ = 'b';
                       goto done;
#if __STDC__
               case '\a':
#else
               case '\007':
#endif
                       *dst++ = '\\';
                       *dst++ = 'a';
                       goto done;
               case '\v':
                       *dst++ = '\\';
                       *dst++ = 'v';
                       goto done;
               case '\t':
                       *dst++ = '\\';
                       *dst++ = 't';
                       goto done;
               case '\f':
                       *dst++ = '\\';
                       *dst++ = 'f';
                       goto done;
               case ' ':
                       *dst++ = '\\';
                       *dst++ = 's';
                       goto done;
               case '\0':
                       *dst++ = '\\';
                       *dst++ = '0';
                       if (isoctal(nextc)) {
                               *dst++ = '0';
                               *dst++ = '0';
                       }
                       goto done;
               }
       }
       if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) {        
               *dst++ = '\\';
               *dst++ = ((u_char)c >> 6 & 07) + '0';
               *dst++ = ((u_char)c >> 3 & 07) + '0';
               *dst++ = ((u_char)c & 07) + '0';
               goto done;
       }
       if ((flag & VIS_NOSLASH) == 0)
               *dst++ = '\\';
       if (c & 0200) {
               c &= 0177;
               *dst++ = 'M';
       }
       if (iscntrl(c)) {
               *dst++ = '^';
               if (c == 0177)
                       *dst++ = '?';
               else
                       *dst++ = c + '@';
       } else {
               *dst++ = '-';
               *dst++ = c;
       }
done:
       *dst = '\0';
       return (dst);
}

/*
* strvis, strvisx - visually encode characters from src into dst
*      
*      Dst must be 4 times the size of src to account for possible
*      expansion.  The length of dst, not including the trailing NULL,
*      is returned. 
*
*      Strvisx encodes exactly len bytes from src into dst.
*      This is useful for encoding a block of data.
*/
int
strvis(dst, src, flag)
       register char *dst;
       register const char *src;
       int flag;
{
       register char c;
       char *start = dst;

       for (;c = *src; src++)
               dst = vis(dst, c, flag, *(src+1));

       return (dst - start);
}

int
strvisx(dst, src, len, flag)
       register char *dst;
       register const char *src;
       register size_t len;
       int flag;
{
       char *start = dst;

       while (len > 1) {
               dst = vis(dst, *src, flag, *(src+1));
               len--;
       }
       if (len)
               dst = vis(dst, *src, flag, '\0');

       return (dst - start);
}