LXR toybox/toys/posix/cat.c

   1/* cat.c - copy inputs to stdout.
   2 *
   3 * Copyright 2006 Rob Landley <rob@landley.net>
   4 *
   5 * See http://opengroup.org/onlinepubs/9699919799/utilities/cat.html
   6
   7USE_CAT(NEWTOY(cat, "uvte", TOYFLAG_BIN))
   8
   9config CAT
  10  bool "cat"
  11  default y
  12  help
  13    usage: cat [-etuv] [FILE...]
  14
  15    Copy (concatenate) files to stdout.  If no files listed, copy from stdin.
  16    Filename "-" is a synonym for stdin.
  17
  18    -e  Mark each newline with $
  19    -t  Show tabs as ^I
  20    -u  Copy one byte at a time (slow)
  21    -v  Display nonprinting characters as escape sequences with M-x for
  22        high ascii characters (>127), and ^x for other nonprinting chars
  23*/
  24
  25#define FOR_cat
  26#define FORCE_FLAGS
  27#include "toys.h"
  28
  29static void do_cat(int fd, char *name)
  30{
  31  int i, len, size=FLAG(u) ? 1 : sizeof(toybuf);
  32
  33  for(;;) {
  34    len = read(fd, toybuf, size);
  35    if (len<0) perror_msg_raw(name);
  36    if (len<1) break;
  37    if (toys.optflags&~FLAG_u) {
  38      for (i = 0; i<len; i++) {
  39        char c = toybuf[i];
  40
  41        if (c>126 && FLAG(v)) {
  42          if (c>127) {
  43            printf("M-");
  44            c -= 128;
  45          }
  46          if (c == 127) {
  47            printf("^?");
  48            continue;
  49          }
  50        }
  51        if (c<32) {
  52          if (c == 10) {
  53            if (FLAG(e)) xputc('$');
  54          } else if (toys.optflags & (c==9 ? FLAG_t : FLAG_v)) {
  55            printf("^%c", c+'@');
  56            continue;
  57          }
  58        }
  59        xputc(c);
  60      }
  61    } else xwrite(1, toybuf, len);
  62  }
  63}
  64
  65void cat_main(void)
  66{
  67  loopfiles(toys.optargs, do_cat);
  68}
  69