lib/support/cstring.c

   1 /*
   2  * cstring.c -- parse and print strings using the C escape sequences
   3  */
   4
   5 #include "config.h"
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <ctype.h>
   9 #ifdef HAVE_GETOPT_H
  10 #include <getopt.h>
  11 #endif
  12 #include <string.h>
  13
  14 #include "cstring.h"
  15
  16 int parse_c_string(char *str)
  17 {
  18         char *to, *from, ch;
  19         int v;
  20
  21         to = from = str;
  22
  23         for (to = from = (char *) str;
  24              *from && *from != '"'; to++, from++) {
  25                 if (*from == '\\') {
  26                         ch = *(++from);
  27                         switch (ch) {
  28                         case 'a':
  29                                 *to = '\a';
  30                                 break;
  31                         case 'b':
  32                                 *to = '\b';
  33                                 break;
  34                         case 'f':
  35                                 *to = '\f';
  36                                 break;
  37                         case 'n':
  38                                 *to = '\n';
  39                                 break;
  40                         case 't':
  41                                 *to = '\t';
  42                                 break;
  43                         case 'v':
  44                                 *to = '\v';
  45                                 break;
  46                         case 'x':
  47                                 ch = *(from + 1);
  48                                 if (ch >= 'a' && ch <= 'f')
  49                                         ch = ch - 'a' + 'A';
  50                                 if (ch >= '0' && ch <= '9')
  51                                         v = ch - '0';
  52                                 else if (ch >= 'A' && ch <= 'F')
  53                                         v = ch + 10 - 'A';
  54                                 else {
  55                                         *to = 'x';
  56                                         break;
  57                                 }
  58                                 from++;
  59                                 ch = *(from + 1);
  60                                 if (ch >= 'a' && ch <= 'f')
  61                                         ch = ch - 'a' + 'A';
  62                                 if (ch >= '0' && ch <= '9')
  63                                         v = (v * 16) + (ch - '0');
  64                                 else if (ch >= 'A' && ch <= 'F')
  65                                         v = (v * 16) + (ch + 10 - 'A');
  66                                 else {
  67                                         *to = 'x';
  68                                         from--;
  69                                         break;
  70                                 }
  71                                 from++;
  72                                 *to = v;
  73                                 break;
  74                         default:
  75                                 if (ch >= '0' && ch <= '9') {
  76                                         v = ch - '0';
  77                                         ch = *(from + 1);
  78                                         if (ch >= '0' && ch <= '9') {
  79                                                 from++;
  80                                                 v = (8 * v) + (ch - '0');
  81                                                 ch = *(from + 1);
  82                                                 if (ch >= '0' && ch <= '9') {
  83                                                         from++;
  84                                                         v = (8 * v) + (ch - '0');
  85                                                 }
  86                                         }
  87                                         ch = v;
  88                                 }
  89                                 *to = ch;
  90                         }
  91                         continue;
  92                 }
  93                 *to = *from;
  94         }
  95         *to = '\0';
  96         return to - (char *) str;
  97 }
  98
  99 void print_c_string(FILE *f, const char *cp, int len)
 100 {
 101         unsigned char   ch;
 102
 103         if (len < 0)
 104                 len = strlen(cp);
 105
 106         while (len--) {
 107                 ch = *cp++;
 108                 if (ch == '\a')
 109                         fputs("\\a", f);
 110                 else if (ch == '\b')
 111                         fputs("\\b", f);
 112                 else if (ch == '\f')
 113                         fputs("\\f", f);
 114                 else if (ch == '\n')
 115                         fputs("\\n", f);
 116                 else if (ch == '\t')
 117                         fputs("\\t", f);
 118                 else if (ch == '\v')
 119                         fputs("\\v", f);
 120                 else if (ch == '\\')
 121                         fputs("\\\\", f);
 122                 else if (ch == '\'')
 123                         fputs("\\\'", f);
 124                 else if (ch == '\"')
 125                         fputs("\\\"", f);
 126                 else if ((ch < 32) || (ch > 126))
 127                         fprintf(f, "\\%03o", ch);
 128                 else
 129                         fputc(ch, f);
 130         }
 131 }
 132
 133 #ifdef DEBUG_PROGRAM
 134 int main(int argc, char **argv)
 135 {
 136         char buf[4096];
 137         int c, raw = 0;
 138
 139         while ((c = getopt(argc, argv, "r")) != EOF) {
 140                 switch (c) {
 141                 case 'r':
 142                         raw++;
 143                         break;
 144                 default:
 145                         fprintf(stderr, "Usage: %s [-r]\n", argv[0]);
 146                         exit(1);
 147                 }
 148         }
 149
 150         while (!feof(stdin)) {
 151                 if (fgets(buf, sizeof(buf), stdin) == NULL)
 152                         break;
 153                 c = parse_c_string(buf);
 154                 if (raw)
 155                         fputs(buf, stdout);
 156                 else {
 157                         print_c_string(stdout, buf, c);
 158                         printf(" <%d>\n", c);
 159                 }
 160         }
 161 }
 162 #endif