modules/src/print/format.c

   1 /*
   2  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3  * See the copyright notice in the ACK home directory, in the file "Copyright".
   4  */
   5 /* $Id: format.c,v 1.9 1994/06/24 11:20:16 ceriel Exp $ */
   6
   7 #include <system.h>
   8 #include "print.h"
   9
  10 extern char *long2str();
  11
  12 static int
  13 integral(c)
  14 {
  15         switch (c) {
  16         case 'b':
  17                 return -2;
  18         case 'd':
  19                 return 10;
  20         case 'o':
  21                 return -8;
  22         case 'u':
  23                 return -10;
  24         case 'x':
  25                 return -16;
  26         }
  27         return 0;
  28 }
  29
  30 /*FORMAT1 $
  31         %s = char *
  32         %l = long
  33         %c = int
  34         %[uxbo] = unsigned int
  35         %d = int
  36 $ */
  37 int
  38 _format(buf, fmt, argp)
  39         char *buf, *fmt;
  40         register va_list argp;
  41 {
  42         register char *pf = fmt;
  43         register char *pb = buf;
  44
  45         while (*pf) {
  46                 if (*pf == '%') {
  47                         register width, base, pad, npad;
  48                         char *arg;
  49                         char cbuf[2];
  50                         char *badformat = "<bad format>";
  51
  52                         /* get padder */
  53                         if (*++pf == '0') {
  54                                 pad = '0';
  55                                 ++pf;
  56                         }
  57                         else
  58                                 pad = ' ';
  59
  60                         /* get width */
  61                         width = 0;
  62                         while (*pf >= '0' && *pf <= '9')
  63                                 width = 10 * width + *pf++ - '0';
  64
  65                         if (*pf == 's') {
  66                                 arg = va_arg(argp, char *);
  67                         }
  68                         else
  69                         if (*pf == 'c') {
  70                                 cbuf[0] = va_arg(argp, int);
  71                                 cbuf[1] = '\0';
  72                                 arg = &cbuf[0];
  73                         }
  74                         else
  75                         if (*pf == 'l') {
  76                                 /* alignment ??? */
  77                                 if (base = integral(*++pf)) {
  78                                         arg = long2str(va_arg(argp,long), base);
  79                                 }
  80                                 else {
  81                                         pf--;
  82                                         arg = badformat;
  83                                 }
  84                         }
  85                         else
  86                         if (base = integral(*pf)) {
  87                                 arg = long2str((long)va_arg(argp,int), base);
  88                         }
  89                         else
  90                         if (*pf == '%')
  91                                 arg = "%";
  92                         else
  93                                 arg = badformat;
  94
  95                         npad = width - strlen(arg);
  96
  97                         while (npad-- > 0)
  98                                 *pb++ = pad;
  99
 100                         while (*pb++ = *arg++);
 101                         pb--;
 102                         pf++;
 103                 }
 104                 else
 105                         *pb++ = *pf++;
 106         }
 107         return pb - buf;
 108 }