git.maemo.org Git - busybox4maemo/blob - coreutils/printf.c

   1 /* vi: set sw=4 ts=4: */
   2 /* printf - format and print data
   3
   4    Copyright 1999 Dave Cinege
   5    Portions copyright (C) 1990-1996 Free Software Foundation, Inc.
   6
   7    Licensed under GPL v2 or later, see file LICENSE in this tarball for details.
   8 */
   9
  10 /* Usage: printf format [argument...]
  11
  12    A front end to the printf function that lets it be used from the shell.
  13
  14    Backslash escapes:
  15
  16    \" = double quote
  17    \\ = backslash
  18    \a = alert (bell)
  19    \b = backspace
  20    \c = produce no further output
  21    \f = form feed
  22    \n = new line
  23    \r = carriage return
  24    \t = horizontal tab
  25    \v = vertical tab
  26    \0ooo = octal number (ooo is 0 to 3 digits)
  27    \xhhh = hexadecimal number (hhh is 1 to 3 digits)
  28
  29    Additional directive:
  30
  31    %b = print an argument string, interpreting backslash escapes
  32
  33    The 'format' argument is re-used as many times as necessary
  34    to convert all of the given arguments.
  35
  36    David MacKenzie <djm@gnu.ai.mit.edu> */
  37
  38
  39 //   19990508 Busy Boxed! Dave Cinege
  40
  41 #include "libbb.h"
  42
  43 typedef void (*converter)(const char *arg, void *result);
  44
  45 static void multiconvert(const char *arg, void *result, converter convert)
  46 {
  47         char s[sizeof(int)*3 + 2];
  48
  49         if (*arg == '"' || *arg == '\'') {
  50                 sprintf(s, "%d", (unsigned char)arg[1]);
  51                 arg = s;
  52         }
  53         convert(arg, result);
  54         /* if there was conversion error, print unconverted string */
  55         if (errno)
  56                 fputs(arg, stderr);
  57 }
  58
  59 static void conv_strtoul(const char *arg, void *result)
  60 {
  61         *(unsigned long*)result = bb_strtoul(arg, NULL, 0);
  62 }
  63 static void conv_strtol(const char *arg, void *result)
  64 {
  65         *(long*)result = bb_strtol(arg, NULL, 0);
  66 }
  67 static void conv_strtod(const char *arg, void *result)
  68 {
  69         char *end;
  70         /* Well, this one allows leading whitespace... so what */
  71         /* What I like much less is that "-" is accepted too! :( */
  72         *(double*)result = strtod(arg, &end);
  73         if (end[0]) errno = ERANGE;
  74 }
  75
  76 static unsigned long my_xstrtoul(const char *arg)
  77 {
  78         unsigned long result;
  79         multiconvert(arg, &result, conv_strtoul);
  80         return result;
  81 }
  82
  83 static long my_xstrtol(const char *arg)
  84 {
  85         long result;
  86         multiconvert(arg, &result, conv_strtol);
  87         return result;
  88 }
  89
  90 static double my_xstrtod(const char *arg)
  91 {
  92         double result;
  93         multiconvert(arg, &result, conv_strtod);
  94         return result;
  95 }
  96
  97 static void print_esc_string(char *str)
  98 {
  99         for (; *str; str++) {
 100                 if (*str == '\\') {
 101                         str++;
 102                         bb_putchar(bb_process_escape_sequence((const char **)&str));
 103                 } else {
 104                         bb_putchar(*str);
 105                 }
 106
 107         }
 108 }
 109
 110 static void print_direc(char *start, size_t length, int field_width, int precision,
 111                 const char *argument)
 112 {
 113         char *p;                /* Null-terminated copy of % directive. */
 114
 115         p = xmalloc((unsigned) (length + 1));
 116         strncpy(p, start, length);
 117         p[length] = 0;
 118
 119         switch (p[length - 1]) {
 120         case 'd':
 121         case 'i':
 122                 if (field_width < 0) {
 123                         if (precision < 0)
 124                                 printf(p, my_xstrtol(argument));
 125                         else
 126                                 printf(p, precision, my_xstrtol(argument));
 127                 } else {
 128                         if (precision < 0)
 129                                 printf(p, field_width, my_xstrtol(argument));
 130                         else
 131                                 printf(p, field_width, precision, my_xstrtol(argument));
 132                 }
 133                 break;
 134         case 'o':
 135         case 'u':
 136         case 'x':
 137         case 'X':
 138                 if (field_width < 0) {
 139                         if (precision < 0)
 140                                 printf(p, my_xstrtoul(argument));
 141                         else
 142                                 printf(p, precision, my_xstrtoul(argument));
 143                 } else {
 144                         if (precision < 0)
 145                                 printf(p, field_width, my_xstrtoul(argument));
 146                         else
 147                                 printf(p, field_width, precision, my_xstrtoul(argument));
 148                 }
 149                 break;
 150         case 'f':
 151         case 'e':
 152         case 'E':
 153         case 'g':
 154         case 'G':
 155                 if (field_width < 0) {
 156                         if (precision < 0)
 157                                 printf(p, my_xstrtod(argument));
 158                         else
 159                                 printf(p, precision, my_xstrtod(argument));
 160                 } else {
 161                         if (precision < 0)
 162                                 printf(p, field_width, my_xstrtod(argument));
 163                         else
 164                                 printf(p, field_width, precision, my_xstrtod(argument));
 165                 }
 166                 break;
 167         case 'c':
 168                 printf(p, *argument);
 169                 break;
 170         case 's':
 171                 if (field_width < 0) {
 172                         if (precision < 0)
 173                                 printf(p, argument);
 174                         else
 175                                 printf(p, precision, argument);
 176                 } else {
 177                         if (precision < 0)
 178                                 printf(p, field_width, argument);
 179                         else
 180                                 printf(p, field_width, precision, argument);
 181                 }
 182                 break;
 183         }
 184
 185         free(p);
 186 }
 187
 188 /* Print the text in FORMAT, using ARGV (with ARGC elements) for
 189    arguments to any '%' directives.
 190    Return the number of elements of ARGV used.  */
 191
 192 static int print_formatted(char *format, int argc, char **argv)
 193 {
 194         int save_argc = argc;   /* Preserve original value.  */
 195         char *f;                /* Pointer into 'format'.  */
 196         char *direc_start;      /* Start of % directive.  */
 197         size_t direc_length;    /* Length of % directive.  */
 198         int field_width;        /* Arg to first '*', or -1 if none.  */
 199         int precision;          /* Arg to second '*', or -1 if none.  */
 200
 201         for (f = format; *f; ++f) {
 202                 switch (*f) {
 203                 case '%':
 204                         direc_start = f++;
 205                         direc_length = 1;
 206                         field_width = precision = -1;
 207                         if (*f == '%') {
 208                                 bb_putchar('%');
 209                                 break;
 210                         }
 211                         if (*f == 'b') {
 212                                 if (argc > 0) {
 213                                         print_esc_string(*argv);
 214                                         ++argv;
 215                                         --argc;
 216                                 }
 217                                 break;
 218                         }
 219                         if (strchr("-+ #", *f)) {
 220                                 ++f;
 221                                 ++direc_length;
 222                         }
 223                         if (*f == '*') {
 224                                 ++f;
 225                                 ++direc_length;
 226                                 if (argc > 0) {
 227                                         field_width = my_xstrtoul(*argv);
 228                                         ++argv;
 229                                         --argc;
 230                                 } else
 231                                         field_width = 0;
 232                         } else {
 233                                 while (isdigit(*f)) {
 234                                         ++f;
 235                                         ++direc_length;
 236                                 }
 237                         }
 238                         if (*f == '.') {
 239                                 ++f;
 240                                 ++direc_length;
 241                                 if (*f == '*') {
 242                                         ++f;
 243                                         ++direc_length;
 244                                         if (argc > 0) {
 245                                                 precision = my_xstrtoul(*argv);
 246                                                 ++argv;
 247                                                 --argc;
 248                                         } else
 249                                                 precision = 0;
 250                                 } else
 251                                         while (isdigit(*f)) {
 252                                                 ++f;
 253                                                 ++direc_length;
 254                                         }
 255                         }
 256                         if (*f == 'l' || *f == 'L' || *f == 'h') {
 257                                 ++f;
 258                                 ++direc_length;
 259                         }
 260                         /*
 261                         if (!strchr ("diouxXfeEgGcs", *f))
 262                         fprintf(stderr, "%%%c: invalid directive", *f);
 263                         */
 264                         ++direc_length;
 265                         if (argc > 0) {
 266                                 print_direc(direc_start, direc_length, field_width,
 267                                                         precision, *argv);
 268                                 ++argv;
 269                                 --argc;
 270                         } else
 271                                 print_direc(direc_start, direc_length, field_width,
 272                                                         precision, "");
 273                         break;
 274                 case '\\':
 275                         if (*++f == 'c')
 276                                 exit(0);
 277                         bb_putchar(bb_process_escape_sequence((const char **)&f));
 278                         f--;
 279                         break;
 280                 default:
 281                         bb_putchar(*f);
 282                 }
 283         }
 284
 285         return save_argc - argc;
 286 }
 287
 288 int printf_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 289 int printf_main(int argc, char **argv)
 290 {
 291         char *format;
 292         int args_used;
 293
 294         if (argc <= 1 || argv[1][0] == '-') {
 295                 bb_show_usage();
 296         }
 297
 298         format = argv[1];
 299         argc -= 2;
 300         argv += 2;
 301
 302         do {
 303                 args_used = print_formatted(format, argc, argv);
 304                 argc -= args_used;
 305                 argv += args_used;
 306         } while (args_used > 0 && argc > 0);
 307
 308 /*      if (argc > 0)
 309                 fprintf(stderr, "excess args ignored");
 310 */
 311
 312         return EXIT_SUCCESS;
 313 }