https://perl5.git.perl.org / perl5.git / blame
| Commit | Line | Data |
|---|---|---|
| 93a17b20 LW |
1 | # &open3: Marc Horowitz <marc@mit.edu> |
| 2 | # derived mostly from &open2 by tom christiansen, <tchrist@convex.com> | |
| 3 | # | |
| 4 | # usage: $pid = open3('wtr', 'rdr', 'err' 'some cmd and args', 'optarg', ...); | |
| 5 | # | |
| 6 | # spawn the given $cmd and connect rdr for | |
| 7 | # reading, wtr for writing, and err for errors. | |
| 8 | # if err is '', or the same as rdr, then stdout and | |
| 9 | # stderr of the child are on the same fh. returns pid | |
| 10 | # of child, or 0 on failure. | |
| 11 | ||
| 12 | ||
| 13 | # if wtr begins with '>&', then wtr will be closed in the parent, and | |
| 14 | # the child will read from it directly. if rdr or err begins with | |
| 15 | # '>&', then the child will send output directly to that fd. In both | |
| 16 | # cases, there will be a dup() instead of a pipe() made. | |
| 17 | ||
| 18 | ||
| 19 | # WARNING: this is dangerous, as you may block forever | |
| 20 | # unless you are very careful. | |
| 21 | # | |
| 22 | # $wtr is left unbuffered. | |
| 23 | # | |
| 24 | # abort program if | |
| 25 | # rdr or wtr are null | |
| 26 | # pipe or fork or exec fails | |
| 27 | ||
| 28 | package open3; | |
| 29 | ||
| 30 | $fh = 'FHOPEN000'; # package static in case called more than once | |
| 31 | ||
| 32 | sub main'open3 { | |
| 33 | local($kidpid); | |
| 34 | local($dad_wtr, $dad_rdr, $dad_err, @cmd) = @_; | |
| 35 | local($dup_wtr, $dup_rdr, $dup_err); | |
| 36 | ||
| 37 | $dad_wtr || die "open3: wtr should not be null"; | |
| 38 | $dad_rdr || die "open3: rdr should not be null"; | |
| 39 | $dad_err = $dad_rdr if ($dad_err eq ''); | |
| 40 | ||
| 41 | $dup_wtr = ($dad_wtr =~ s/^\>\&//); | |
| 42 | $dup_rdr = ($dad_rdr =~ s/^\>\&//); | |
| 43 | $dup_err = ($dad_err =~ s/^\>\&//); | |
| 44 | ||
| 45 | # force unqualified filehandles into callers' package | |
| 46 | local($package) = caller; | |
| 47 | $dad_wtr =~ s/^[^']+$/$package'$&/; | |
| 48 | $dad_rdr =~ s/^[^']+$/$package'$&/; | |
| 49 | $dad_err =~ s/^[^']+$/$package'$&/; | |
| 50 | ||
| 51 | local($kid_rdr) = ++$fh; | |
| 52 | local($kid_wtr) = ++$fh; | |
| 53 | local($kid_err) = ++$fh; | |
| 54 | ||
| 55 | if (!$dup_wtr) { | |
| 56 | pipe($kid_rdr, $dad_wtr) || die "open3: pipe 1 (stdin) failed: $!"; | |
| 57 | } | |
| 58 | if (!$dup_rdr) { | |
| 59 | pipe($dad_rdr, $kid_wtr) || die "open3: pipe 2 (stdout) failed: $!"; | |
| 60 | } | |
| 61 | if ($dad_err ne $dad_rdr && !$dup_err) { | |
| 62 | pipe($dad_err, $kid_err) || die "open3: pipe 3 (stderr) failed: $!"; | |
| 63 | } | |
| 64 | ||
| 65 | if (($kidpid = fork) < 0) { | |
| 66 | die "open2: fork failed: $!"; | |
| 67 | } elsif ($kidpid == 0) { | |
| 68 | if ($dup_wtr) { | |
| 69 | open(STDIN, ">&$dad_wtr") if (fileno(STDIN) != fileno($dad_wtr)); | |
| 70 | } else { | |
| 71 | close($dad_wtr); | |
| 72 | open(STDIN, ">&$kid_rdr"); | |
| 73 | } | |
| 74 | if ($dup_rdr) { | |
| 75 | open(STDOUT, ">&$dad_rdr") if (fileno(STDOUT) != fileno($dad_rdr)); | |
| 76 | } else { | |
| 77 | close($dad_rdr); | |
| 78 | open(STDOUT, ">&$kid_wtr"); | |
| 79 | } | |
| 80 | if ($dad_rdr ne $dad_err) { | |
| 81 | if ($dup_err) { | |
| 82 | open(STDERR, ">&$dad_err") | |
| 83 | if (fileno(STDERR) != fileno($dad_err)); | |
| 84 | } else { | |
| 85 | close($dad_err); | |
| 86 | open(STDERR, ">&$kid_err"); | |
| 87 | } | |
| 88 | } else { | |
| 89 | open(STDERR, ">&STDOUT") if (fileno(STDERR) != fileno(STDOUT)); | |
| 90 | } | |
| 91 | exec @cmd; | |
| 92 | ||
| 93 | local($")=(" "); | |
| 94 | die "open2: exec of @cmd failed"; | |
| 95 | } | |
| 96 | ||
| 97 | close $kid_rdr; close $kid_wtr; close $kid_err; | |
| 98 | if ($dup_wtr) { | |
| 99 | close($dad_wtr); | |
| 100 | } | |
| 101 | ||
| 102 | select((select($dad_wtr), $| = 1)[0]); # unbuffer pipe | |
| 103 | $kidpid; | |
| 104 | } | |
| 105 | 1; # so require is happy |