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 *format, unsigned fmt_length,
 111                 int field_width, int precision,
 112                 const char *argument)
 113 {
 114         char saved;
 115
 116         saved = format[fmt_length];
 117         format[fmt_length] = '\0';
 118
 119         switch (p[fmt_length - 1]) {
 120         case 'd':
 121         case 'i':
 122                 if (field_width < 0) {
 123                         if (precision < 0)
 124                                 printf(format, my_xstrtol(argument));
 125                         else
 126                                 printf(format, precision, my_xstrtol(argument));
 127                 } else {
 128                         if (precision < 0)
 129                                 printf(format, field_width, my_xstrtol(argument));
 130                         else
 131                                 printf(format, 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(format, my_xstrtoul(argument));
 141                         else
 142                                 printf(format, precision, my_xstrtoul(argument));
 143                 } else {
 144                         if (precision < 0)
 145                                 printf(format, field_width, my_xstrtoul(argument));
 146                         else
 147                                 printf(format, 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(format, my_xstrtod(argument));
 158                         else
 159                                 printf(format, precision, my_xstrtod(argument));
 160                 } else {
 161                         if (precision < 0)
 162                                 printf(format, field_width, my_xstrtod(argument));
 163                         else
 164                                 printf(format, field_width, precision, my_xstrtod(argument));
 165                 }
 166                 break;
 167         case 'c':
 168                 printf(format, *argument);
 169                 break;
 170         case 's':
 171                 if (field_width < 0) {
 172                         if (precision < 0)
 173                                 printf(format, argument);
 174                         else
 175                                 printf(format, precision, argument);
 176                 } else {
 177                         if (precision < 0)
 178                                 printf(format, field_width, argument);
 179                         else
 180                                 printf(format, field_width, precision, argument);
 181                 }
 182                 break;
 183         }
 184
 185         format[fmt_length] = saved;
 186 }
 187
 188 /* Print the text in FORMAT, using ARGV for arguments to any '%' directives.
 189    Return advanced ARGV.  */
 190 static char **print_formatted(char *f, char **argv)
 191 {
 192         char *direc_start;      /* Start of % directive.  */
 193         unsigned direc_length;  /* Length of % directive.  */
 194         int field_width;        /* Arg to first '*', or -1 if none.  */
 195         int precision;          /* Arg to second '*', or -1 if none.  */
 196
 197         for (; *f; ++f) {
 198                 switch (*f) {
 199                 case '%':
 200                         direc_start = f++;
 201                         direc_length = 1;
 202                         field_width = precision = -1;
 203                         if (*f == '%') {
 204                                 bb_putchar('%');
 205                                 break;
 206                         }
 207                         if (*f == 'b') {
 208                                 if (*argv) {
 209                                         print_esc_string(*argv);
 210                                         ++argv;
 211                                 }
 212                                 break;
 213                         }
 214                         if (strchr("-+ #", *f)) {
 215                                 ++f;
 216                                 ++direc_length;
 217                         }
 218                         if (*f == '*') {
 219                                 ++f;
 220                                 ++direc_length;
 221                                 if (*argv) {
 222                                         field_width = my_xstrtoul(*argv);
 223                                         ++argv;
 224                                 } else
 225                                         field_width = 0;
 226                         } else {
 227                                 while (isdigit(*f)) {
 228                                         ++f;
 229                                         ++direc_length;
 230                                 }
 231                         }
 232                         if (*f == '.') {
 233                                 ++f;
 234                                 ++direc_length;
 235                                 if (*f == '*') {
 236                                         ++f;
 237                                         ++direc_length;
 238                                         if (*argv) {
 239                                                 precision = my_xstrtoul(*argv);
 240                                                 ++argv;
 241                                         } else
 242                                                 precision = 0;
 243                                 } else
 244                                         while (isdigit(*f)) {
 245                                                 ++f;
 246                                                 ++direc_length;
 247                                         }
 248                         }
 249                         if (*f == 'l' || *f == 'L' || *f == 'h') {
 250                                 ++f;
 251                                 ++direc_length;
 252                         }
 253                         /*
 254                         if (!strchr ("diouxXfeEgGcs", *f))
 255                         fprintf(stderr, "%%%c: invalid directive", *f);
 256                         */
 257                         ++direc_length;
 258                         if (*argv) {
 259                                 print_direc(direc_start, direc_length, field_width,
 260                                                         precision, *argv);
 261                                 ++argv;
 262                         } else
 263                                 print_direc(direc_start, direc_length, field_width,
 264                                                         precision, "");
 265                         break;
 266                 case '\\':
 267                         if (*++f == 'c')
 268                                 exit(EXIT_SUCCESS);
 269                         bb_putchar(bb_process_escape_sequence((const char **)&f));
 270                         f--;
 271                         break;
 272                 default:
 273                         bb_putchar(*f);
 274                 }
 275         }
 276
 277         return argv;
 278 }
 279
 280 int printf_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 281 int printf_main(int argc ATTRIBUTE_UNUSED, char **argv)
 282 {
 283         char *format;
 284         char **argv2;
 285
 286         /* bash builtin errors out on "printf '-%s-\n' foo",
 287          * coreutils-6.9 works. Both work with "printf -- '-%s-\n' foo".
 288          * We will mimic coreutils. */
 289         if (argv[1] && argv[1][0] == '-' && argv[1][1] == '-' && argv[1][2] == '\0')
 290                 argv++;
 291         if (!argv[1])
 292                 bb_show_usage();
 293
 294         format = argv[1];
 295         argv2 = argv + 2;
 296
 297         do {
 298                 argv = argv2;
 299                 argv2 = print_formatted(format, argv);
 300         } while (argv2 != argv && *argv2);
 301
 302         /* coreutils compat (bash doesn't do this):
 303         if (*argv)
 304                 fprintf(stderr, "excess args ignored");
 305         */
 306
 307         return EXIT_SUCCESS;
 308 }