contrib/tcp_wrappers/vfprintf.c

   1  /*
   2   * vfprintf() and vprintf() clones. They will produce unexpected results
   3   * when excessive dynamic ("*") field widths are specified. To be used for
   4   * testing purposes only.
   5   *
   6   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
   7   */
   8
   9 #ifndef lint
  10 static char sccsid[] = "@(#) vfprintf.c 1.2 94/03/23 17:44:46";
  11 #endif
  12
  13 #include <stdio.h>
  14 #include <ctype.h>
  15 #ifdef __STDC__
  16 #include <stdarg.h>
  17 #else
  18 #include <varargs.h>
  19 #endif
  20
  21 /* vfprintf - print variable-length argument list to stream */
  22
  23 int     vfprintf(fp, format, ap)
  24 FILE   *fp;
  25 char   *format;
  26 va_list ap;
  27 {
  28     char    fmt[BUFSIZ];                /* format specifier */
  29     register char *fmtp;
  30     register char *cp;
  31     int     count = 0;
  32
  33     /*
  34      * Iterate over characters in the format string, picking up arguments
  35      * when format specifiers are found.
  36      */
  37
  38     for (cp = format; *cp; cp++) {
  39         if (*cp != '%') {
  40             putc(*cp, fp);                      /* ordinary character */
  41             count++;
  42         } else {
  43
  44             /*
  45              * Format specifiers are handled one at a time, since we can only
  46              * deal with arguments one at a time. Try to determine the end of
  47              * the format specifier. We do not attempt to fully parse format
  48              * strings, since we are ging to let fprintf() do the hard work.
  49              * In regular expression notation, we recognize:
  50              *
  51              * %-?0?([0-9]+|\*)?\.?([0-9]+|\*)?l?[a-z]
  52              *
  53              * which includes some combinations that do not make sense.
  54              */
  55
  56             fmtp = fmt;
  57             *fmtp++ = *cp++;
  58             if (*cp == '-')                     /* left-adjusted field? */
  59                 *fmtp++ = *cp++;
  60             if (*cp == '0')                     /* zero-padded field? */
  61                 *fmtp++ = *cp++;
  62             if (*cp == '*') {                   /* dynamic field witdh */
  63                 sprintf(fmtp, "%d", va_arg(ap, int));
  64                 fmtp += strlen(fmtp);
  65                 cp++;
  66             } else {
  67                 while (isdigit(*cp))            /* hard-coded field width */
  68                     *fmtp++ = *cp++;
  69             }
  70             if (*cp == '.')                     /* width/precision separator */
  71                 *fmtp++ = *cp++;
  72             if (*cp == '*') {                   /* dynamic precision */
  73                 sprintf(fmtp, "%d", va_arg(ap, int));
  74                 fmtp += strlen(fmtp);
  75                 cp++;
  76             } else {
  77                 while (isdigit(*cp))            /* hard-coded precision */
  78                     *fmtp++ = *cp++;
  79             }
  80             if (*cp == 'l')                     /* long whatever */
  81                 *fmtp++ = *cp++;
  82             if (*cp == 0)                       /* premature end, punt */
  83                 break;
  84             *fmtp++ = *cp;                      /* type (checked below) */
  85             *fmtp = 0;
  86
  87             /* Execute the format string - let fprintf() do the hard work. */
  88
  89             switch (fmtp[-1]) {
  90             case 's':                           /* string-valued argument */
  91                 count += fprintf(fp, fmt, va_arg(ap, char *));
  92                 break;
  93             case 'c':                           /* integral-valued argument */
  94             case 'd':
  95             case 'u':
  96             case 'o':
  97             case 'x':
  98                 if (fmtp[-2] == 'l')
  99                     count += fprintf(fp, fmt, va_arg(ap, long));
 100                 else
 101                     count += fprintf(fp, fmt, va_arg(ap, int));
 102                 break;
 103             case 'e':                           /* float-valued argument */
 104             case 'f':
 105             case 'g':
 106                 count += fprintf(fp, fmt, va_arg(ap, double));
 107                 break;
 108             default:                            /* anything else */
 109                 putc(fmtp[-1], fp);
 110                 count++;
 111                 break;
 112             }
 113         }
 114     }
 115     return (count);
 116 }
 117
 118 /* vprintf - print variable-length argument list to stdout */
 119
 120 vprintf(format, ap)
 121 char   *format;
 122 va_list ap;
 123 {
 124     return (vfprintf(stdout, format, ap));
 125 }