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      1 /*strings.c - print the strings of printable characters in files.
      2  *
      3  * Copyright 2014 Kyung-su Kim <kaspyx (at) gmail.com>
      4  * Copyright 2014 Kyungwan Han <asura321 (at) gmail.com>
      5  *
      6  * No Standard
      7  * TODO: utf8 strings
      8  * TODO: posix -t
      9 
     10 USE_STRINGS(NEWTOY(strings, "an#=4<1fo", TOYFLAG_USR|TOYFLAG_BIN))
     11 
     12 config STRINGS
     13   bool "strings"
     14   default y
     15   help
     16     usage: strings [-fo] [-n LEN] [FILE...]
     17 
     18     Display printable strings in a binary file
     19 
     20     -f	Precede strings with filenames
     21     -n	At least LEN characters form a string (default 4)
     22     -o	Precede strings with decimal offsets
     23 */
     24 
     25 #define FOR_strings
     26 #include "toys.h"
     27 
     28 GLOBALS(
     29   long num;
     30 )
     31 
     32 static void do_strings(int fd, char *filename)
     33 {
     34   int nread, i, wlen = TT.num, count = 0;
     35   off_t offset = 0;
     36   char *string = xzalloc(wlen + 1);
     37 
     38   for (;;) {
     39     nread = read(fd, toybuf, sizeof(toybuf));
     40     if (nread < 0) perror_msg_raw(filename);
     41     if (nread < 1) break;
     42     for (i = 0; i < nread; i++, offset++) {
     43       if (((toybuf[i] >= 32) && (toybuf[i] <= 126)) || (toybuf[i] == '\t')) {
     44         if (count == wlen) fputc(toybuf[i], stdout);
     45         else {
     46           string[count++] = toybuf[i];
     47           if (count == wlen) {
     48             if (toys.optflags & FLAG_f) printf("%s: ", filename);
     49             if (toys.optflags & FLAG_o)
     50               printf("%7lld ",(long long)(offset - wlen));
     51             printf("%s", string);
     52           }
     53         }
     54       } else {
     55         if (count == wlen) xputc('\n');
     56         count = 0;
     57       }
     58     }
     59   }
     60   xclose(fd);
     61   free(string);
     62 }
     63 
     64 void strings_main(void)
     65 {
     66   loopfiles(toys.optargs, do_strings);
     67 }
     68