| Commit | Line | Data |
|---|
| a0d0e21e |
1 | package IPC::Open2; |
| 2 | require 5.000; |
| 3 | require Exporter; |
| 4 | use Carp; |
| 5 | |
| 6 | @ISA = qw(Exporter); |
| 7 | @EXPORT = qw(open2); |
| 8 | |
| 9 | # &open2: tom christiansen, <tchrist@convex.com> |
| 10 | # |
| 11 | # usage: $pid = open2('rdr', 'wtr', 'some cmd and args'); |
| 12 | # or $pid = open2('rdr', 'wtr', 'some', 'cmd', 'and', 'args'); |
| 13 | # |
| 14 | # spawn the given $cmd and connect $rdr for |
| 15 | # reading and $wtr for writing. return pid |
| 16 | # of child, or 0 on failure. |
| 17 | # |
| 18 | # WARNING: this is dangerous, as you may block forever |
| 19 | # unless you are very careful. |
| 20 | # |
| 21 | # $wtr is left unbuffered. |
| 22 | # |
| 23 | # abort program if |
| 24 | # rdr or wtr are null |
| 25 | # pipe or fork or exec fails |
| 26 | |
| 27 | $fh = 'FHOPEN000'; # package static in case called more than once |
| 28 | |
| 29 | sub open2 { |
| 30 | local($kidpid); |
| 31 | local($dad_rdr, $dad_wtr, @cmd) = @_; |
| 32 | |
| 33 | $dad_rdr ne '' || croak "open2: rdr should not be null"; |
| 34 | $dad_wtr ne '' || croak "open2: wtr should not be null"; |
| 35 | |
| 36 | # force unqualified filehandles into callers' package |
| 37 | local($package) = caller; |
| 38 | $dad_rdr =~ s/^[^']+$/$package'$&/; |
| 39 | $dad_wtr =~ s/^[^']+$/$package'$&/; |
| 40 | |
| 41 | local($kid_rdr) = ++$fh; |
| 42 | local($kid_wtr) = ++$fh; |
| 43 | |
| 44 | pipe($dad_rdr, $kid_wtr) || croak "open2: pipe 1 failed: $!"; |
| 45 | pipe($kid_rdr, $dad_wtr) || croak "open2: pipe 2 failed: $!"; |
| 46 | |
| 47 | if (($kidpid = fork) < 0) { |
| 48 | croak "open2: fork failed: $!"; |
| 49 | } elsif ($kidpid == 0) { |
| 50 | close $dad_rdr; close $dad_wtr; |
| 51 | open(STDIN, "<&$kid_rdr"); |
| 52 | open(STDOUT, ">&$kid_wtr"); |
| 53 | warn "execing @cmd\n" if $debug; |
| 54 | exec @cmd; |
| 55 | croak "open2: exec of @cmd failed"; |
| 56 | } |
| 57 | close $kid_rdr; close $kid_wtr; |
| 58 | select((select($dad_wtr), $| = 1)[0]); # unbuffer pipe |
| 59 | $kidpid; |
| 60 | } |
| 61 | 1; # so require is happy |
| 62 | |
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