errno

   1 #!/usr/bin/perl
   2 ##
   3 ## Prints out error message according to name or number
   4 ## Copyright (c) 2010 by Michal Nazarewicz (mina86/AT/mina86.com)
   5 ##
   6 ## This program is free software; you can redistribute it and/or modify
   7 ## it under the terms of the GNU General Public License as published by
   8 ## the Free Software Foundation; either version 3 of the License, or
   9 ## (at your option) any later version.
  10 ##
  11 ## This program is distributed in the hope that it will be useful,
  12 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ## GNU General Public License for more details.
  15 ##
  16 ## You should have received a copy of the GNU General Public License
  17 ## along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 ##
  19 ## This is part of Tiny Applications Collection
  20 ##   -> http://tinyapps.sourceforge.net/
  21 ##
  22
  23 use warnings;
  24 use strict;
  25
  26 use POSIX qw(strerror);
  27 use FileHandle;
  28 use IPC::Open2;
  29
  30
  31 unless (@ARGV) {
  32         print "usage: errno <error> [ ... ]\n  where <error> is either an errno number or EFOO symbol.\n  Requires gcc to work.\n";
  33         exit 0;
  34 }
  35
  36
  37 my (%names, %nums);
  38
  39 open2(*IN, *OUT, "gcc -E -dM -") or die "gcc: $!\n";
  40
  41 print OUT "#include <errno.h>\n";
  42 close OUT;
  43
  44 while (<IN>) {
  45         if (/^#define\s+(E[A-Z0-9]+)\s+(\d+)\s*$/) {
  46                 my $n = int $2;
  47                 $nums{$1} = $n;
  48                 $names{$n} = $1 unless exists $names{$n};
  49         }
  50 }
  51 close IN;
  52
  53
  54 for (@ARGV) {
  55         my ($name, $num, $err);
  56
  57         if (/^-?\d+$/) {
  58                 $num = abs $_;
  59                 $name = $names{$num} // 'unknown';
  60         } elsif (/^E[A-Z0-9]+$/i) {
  61                 $name = uc $_;
  62                 $num = $nums{$name};
  63                 if (!defined $num) {
  64                         print STDERR "$name: no such error\n";
  65                         next;
  66                 }
  67         } else {
  68                 print STDERR "$_: ignoring\n";
  69                 next;
  70         }
  71
  72         $err = strerror($num);
  73         if ($err) {
  74                 print "$num: $name: $err\n";
  75         } else {
  76                 print STDERR "$num: $name: no such error\n";
  77         }
  78 }