Security Advisories (19)
The XSLoader::load method in XSLoader in Perl does not properly locate .so files when called in a string eval, which might allow local users to execute arbitrary code via a Trojan horse library under the current working directory.
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5RFDMASVZLFZYBB2GNTZXU6I76E4NA4V/
- https://github.com/Perl/perl5/commit/08e3451d7b3b714ad63a27f1b9c2a23ee75d15ee
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PRIPTDA6XINBVEJXI2NGLKVEINBREHTN/
- http://www.openwall.com/lists/oss-security/2016/07/07/1
- http://www.openwall.com/lists/oss-security/2016/07/08/5
- https://rt.cpan.org/Public/Bug/Display.html?id=115808
- http://www.debian.org/security/2016/dsa-3628
- http://www.securitytracker.com/id/1036260
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ITYZJXQH24X2F2LAOQEQAC5KXLYJTJ76/
- http://www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html
- http://www.securityfocus.com/bid/91685
- https://security.gentoo.org/glsa/201701-75
- https://usn.ubuntu.com/3625-2/
- https://usn.ubuntu.com/3625-1/
- https://github.com/Perl/perl5/blob/blead/pod/perl5260delta.pod
regcomp.c in Perl before 5.30.3 allows a buffer overflow via a crafted regular expression because of recursive S_study_chunk calls.
- https://github.com/Perl/perl5/compare/v5.30.2...v5.30.3
- https://github.com/Perl/perl5/blob/blead/pod/perl5303delta.pod
- https://github.com/Perl/perl5/issues/16947
- https://github.com/perl/perl5/commit/66bbb51b93253a3f87d11c2695cfb7bdb782184a
- https://github.com/Perl/perl5/issues/17743
- https://security.netapp.com/advisory/ntap-20200611-0001/
- https://security.gentoo.org/glsa/202006-03
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IN3TTBO5KSGWE5IRIKDJ5JSQRH7ANNXE/
- http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00044.html
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://www.oracle.com/security-alerts/cpujan2021.html
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://perldoc.perl.org/perl5283delta
- https://perldoc.perl.org/perl5303delta
- https://perldoc.perl.org/perl5320delta
Perl before 5.30.3 has an integer overflow related to mishandling of a "PL_regkind[OP(n)] == NOTHING" situation. A crafted regular expression could lead to malformed bytecode with a possibility of instruction injection.
- https://github.com/Perl/perl5/compare/v5.30.2...v5.30.3
- https://github.com/perl/perl5/commit/3295b48defa0f8570114877b063fe546dd348b3c
- https://github.com/perl/perl5/commit/0a320d753fe7fca03df259a4dfd8e641e51edaa8
- https://github.com/Perl/perl5/blob/blead/pod/perl5303delta.pod
- https://security.netapp.com/advisory/ntap-20200611-0001/
- https://security.gentoo.org/glsa/202006-03
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IN3TTBO5KSGWE5IRIKDJ5JSQRH7ANNXE/
- http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00044.html
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://www.oracle.com/security-alerts/cpujan2021.html
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://perldoc.perl.org/perl5283delta
- https://perldoc.perl.org/perl5303delta
- https://perldoc.perl.org/perl5320delta
Perl before 5.30.3 on 32-bit platforms allows a heap-based buffer overflow because nested regular expression quantifiers have an integer overflow.
- https://github.com/Perl/perl5/compare/v5.30.2...v5.30.3
- https://github.com/perl/perl5/commit/897d1f7fd515b828e4b198d8b8bef76c6faf03ed
- https://github.com/Perl/perl5/blob/blead/pod/perl5303delta.pod
- https://security.netapp.com/advisory/ntap-20200611-0001/
- https://security.gentoo.org/glsa/202006-03
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IN3TTBO5KSGWE5IRIKDJ5JSQRH7ANNXE/
- http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00044.html
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://www.oracle.com/security-alerts/cpujan2021.html
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://perldoc.perl.org/perl5283delta
- https://perldoc.perl.org/perl5303delta
- https://perldoc.perl.org/perl5320delta
An issue was discovered in Perl 5.22 through 5.26. Matching a crafted locale dependent regular expression can cause a heap-based buffer over-read and potentially information disclosure.
- https://www.debian.org/security/2018/dsa-4172
- https://rt.perl.org/Public/Bug/Display.html?id=132063
- http://www.securitytracker.com/id/1040681
- https://access.redhat.com/errata/RHSA-2018:1192
- https://usn.ubuntu.com/3625-1/
- https://security.gentoo.org/glsa/201909-01
- https://www.oracle.com/security-alerts/cpujul2020.html
- https://perldoc.perl.org/perl5244delta
- https://perldoc.perl.org/perl5262delta
- https://github.com/Perl/perl5/issues/16143
An issue was discovered in Perl 5.18 through 5.26. A crafted regular expression can cause a heap-based buffer overflow, with control over the bytes written.
- https://www.debian.org/security/2018/dsa-4172
- https://rt.perl.org/Public/Bug/Display.html?id=132227
- http://www.securitytracker.com/id/1040681
- https://access.redhat.com/errata/RHSA-2018:1192
- https://usn.ubuntu.com/3625-1/
- http://www.securitytracker.com/id/1042004
- https://security.gentoo.org/glsa/201909-01
- https://www.oracle.com/security-alerts/cpujul2020.html
- https://perldoc.perl.org/perl5244delta
- https://perldoc.perl.org/perl5262delta
Heap-based buffer overflow in the pack function in Perl before 5.26.2 allows context-dependent attackers to execute arbitrary code via a large item count.
- https://www.debian.org/security/2018/dsa-4172
- https://rt.perl.org/Public/Bug/Display.html?id=131844
- https://lists.debian.org/debian-lts-announce/2018/04/msg00009.html
- http://www.securitytracker.com/id/1040681
- https://usn.ubuntu.com/3625-2/
- https://usn.ubuntu.com/3625-1/
- http://www.securityfocus.com/bid/103953
- https://security.gentoo.org/glsa/201909-01
- https://www.oracle.com/security-alerts/cpujul2020.html
- https://perldoc.perl.org/perl5244delta
- https://perldoc.perl.org/perl5262delta
- https://github.com/Perl/perl5/issues/16098
Perl before 5.26.3 has a buffer overflow via a crafted regular expression that triggers invalid write operations.
- https://www.debian.org/security/2018/dsa-4347
- https://rt.perl.org/Ticket/Display.html?id=131649
- https://metacpan.org/changes/release/SHAY/perl-5.26.3
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RWQGEB543QN7SSBRKYJM6PSOC3RLYGSM/
- https://github.com/Perl/perl5/commit/19a498a461d7c81ae3507c450953d1148efecf4f
- https://bugzilla.redhat.com/show_bug.cgi?id=1646751
- http://www.securitytracker.com/id/1042181
- https://usn.ubuntu.com/3834-1/
- http://www.securityfocus.com/bid/106145
- https://access.redhat.com/errata/RHSA-2019:0010
- https://access.redhat.com/errata/RHSA-2019:0001
- https://security.netapp.com/advisory/ntap-20190221-0003/
- https://security.gentoo.org/glsa/201909-01
- https://www.oracle.com/security-alerts/cpujul2020.html
Perl before 5.26.3 has a buffer over-read via a crafted regular expression that triggers disclosure of sensitive information from process memory.
- https://www.debian.org/security/2018/dsa-4347
- https://usn.ubuntu.com/3834-2/
- https://rt.perl.org/Ticket/Display.html?id=133192
- https://metacpan.org/changes/release/SHAY/perl-5.26.3
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RWQGEB543QN7SSBRKYJM6PSOC3RLYGSM/
- https://github.com/Perl/perl5/commit/43b2f4ef399e2fd7240b4eeb0658686ad95f8e62
- https://bugzilla.redhat.com/show_bug.cgi?id=1646738
- http://www.securitytracker.com/id/1042181
- https://usn.ubuntu.com/3834-1/
- https://access.redhat.com/errata/RHSA-2019:0010
- https://access.redhat.com/errata/RHSA-2019:0001
- https://security.netapp.com/advisory/ntap-20190221-0003/
- https://support.apple.com/kb/HT209600
- https://seclists.org/bugtraq/2019/Mar/42
- http://seclists.org/fulldisclosure/2019/Mar/49
- https://security.gentoo.org/glsa/201909-01
- https://www.oracle.com/security-alerts/cpujul2020.html
Perl before 5.26.3 and 5.28.0 before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.
- https://www.debian.org/security/2018/dsa-4347
- https://rt.perl.org/Public/Bug/Display.html?id=133423
- https://metacpan.org/changes/release/SHAY/perl-5.28.1
- https://metacpan.org/changes/release/SHAY/perl-5.26.3
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RWQGEB543QN7SSBRKYJM6PSOC3RLYGSM/
- https://bugzilla.redhat.com/show_bug.cgi?id=1646734
- http://www.securitytracker.com/id/1042181
- https://usn.ubuntu.com/3834-1/
- http://www.securityfocus.com/bid/106179
- https://access.redhat.com/errata/RHSA-2019:0010
- https://access.redhat.com/errata/RHSA-2019:0001
- https://security.netapp.com/advisory/ntap-20190221-0003/
- https://security.gentoo.org/glsa/201909-01
- https://www.oracle.com/security-alerts/cpujul2020.html
- https://perldoc.perl.org/perl5281delta
- https://perldoc.perl.org/perl5263delta
Perl before 5.26.3 and 5.28.x before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.
- https://www.debian.org/security/2018/dsa-4347
- https://usn.ubuntu.com/3834-2/
- https://rt.perl.org/Ticket/Display.html?id=133204
- https://metacpan.org/changes/release/SHAY/perl-5.28.1
- https://metacpan.org/changes/release/SHAY/perl-5.26.3
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RWQGEB543QN7SSBRKYJM6PSOC3RLYGSM/
- https://lists.debian.org/debian-lts-announce/2018/11/msg00039.html
- https://github.com/Perl/perl5/commit/34716e2a6ee2af96078d62b065b7785c001194be
- https://bugzilla.redhat.com/show_bug.cgi?id=1646730
- http://www.securitytracker.com/id/1042181
- https://usn.ubuntu.com/3834-1/
- http://www.securityfocus.com/bid/106145
- https://access.redhat.com/errata/RHSA-2019:0010
- https://access.redhat.com/errata/RHSA-2019:0001
- https://access.redhat.com/errata/RHSA-2019:0109
- https://security.netapp.com/advisory/ntap-20190221-0003/
- https://support.apple.com/kb/HT209600
- https://seclists.org/bugtraq/2019/Mar/42
- http://seclists.org/fulldisclosure/2019/Mar/49
- https://kc.mcafee.com/corporate/index?page=content&id=SB10278
- https://access.redhat.com/errata/RHBA-2019:0327
- https://access.redhat.com/errata/RHSA-2019:1790
- https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html
- https://access.redhat.com/errata/RHSA-2019:1942
- https://access.redhat.com/errata/RHSA-2019:2400
- https://security.gentoo.org/glsa/201909-01
- https://www.oracle.com/security-alerts/cpuapr2020.html
- https://www.oracle.com/security-alerts/cpujul2020.html
- https://perldoc.perl.org/perl5281delta
- https://perldoc.perl.org/perl5263delta
Buffer overflow in the S_grok_bslash_N function in regcomp.c in Perl 5 before 5.24.3-RC1 and 5.26.x before 5.26.1-RC1 allows remote attackers to disclose sensitive information or cause a denial of service (application crash) via a crafted regular expression with an invalid '\\N{U+...}' escape.
- https://perl5.git.perl.org/perl.git/log/refs/tags/v5.26.1-RC1
- https://perl5.git.perl.org/perl.git/log/refs/tags/v5.24.3-RC1
- https://perl5.git.perl.org/perl.git/commitdiff/2be4edede4ae226e2eebd4eff28cedd2041f300f#patch1
- https://bugzilla.redhat.com/show_bug.cgi?id=1492093
- http://www.securityfocus.com/bid/100852
- http://mirror.cucumberlinux.com/cucumber/cucumber-1.0/source/lang-base/perl/patches/CVE-2017-12883.patch
- https://rt.perl.org/Public/Bug/Display.html?id=131598
- http://www.debian.org/security/2017/dsa-3982
- https://security.netapp.com/advisory/ntap-20180426-0001/
- https://www.oracle.com/security-alerts/cpujul2020.html
- https://github.com/Perl/perl5/issues/16025
- https://perldoc.perl.org/perl5243delta
- https://perldoc.perl.org/perl5280delta
- https://perldoc.perl.org/perl5261delta
Heap-based buffer overflow in the S_regatom function in regcomp.c in Perl 5 before 5.24.3-RC1 and 5.26.x before 5.26.1-RC1 allows remote attackers to cause a denial of service (out-of-bounds write) via a regular expression with a '\\N{}' escape and the case-insensitive modifier.
- https://perl5.git.perl.org/perl.git/log/refs/tags/v5.26.1-RC1
- https://perl5.git.perl.org/perl.git/log/refs/tags/v5.24.3-RC1
- https://perl5.git.perl.org/perl.git/commitdiff/96c83ed78aeea1a0496dd2b2d935869a822dc8a5
- https://bugzilla.redhat.com/show_bug.cgi?id=1492091
- http://www.securityfocus.com/bid/100860
- https://rt.perl.org/Public/Bug/Display.html?id=131582
- http://www.debian.org/security/2017/dsa-3982
- https://security.netapp.com/advisory/ntap-20180426-0001/
- https://www.oracle.com/security-alerts/cpujul2020.html
- https://github.com/Perl/perl5/issues/16021
- https://perldoc.perl.org/perl5243delta
- https://perldoc.perl.org/perl5261delta
- https://perldoc.perl.org/perl5280delta
The (1) S_reghop3, (2) S_reghop4, and (3) S_reghopmaybe3 functions in regexec.c in Perl before 5.24.0 allow context-dependent attackers to cause a denial of service (infinite loop) via crafted utf-8 data, as demonstrated by "a\x80."
- http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183592.html
- http://www.openwall.com/lists/oss-security/2016/04/20/7
- https://bugzilla.redhat.com/show_bug.cgi?id=1329106
- https://rt.perl.org/Public/Bug/Display.html?id=123562
- http://www.openwall.com/lists/oss-security/2016/04/20/5
- http://perl5.git.perl.org/perl.git/commitdiff/22b433eff9a1ffa2454e18405a56650f07b385b5
- https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
- http://www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html
- http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
- http://www.securityfocus.com/bid/86707
- https://security.gentoo.org/glsa/201701-75
- https://usn.ubuntu.com/3625-2/
- https://usn.ubuntu.com/3625-1/
In Perl before 5.38.2, S_parse_uniprop_string in regcomp.c can write to unallocated space because a property name associated with a \p{...} regular expression construct is mishandled. The earliest affected version is 5.30.0.
A heap buffer overflow vulnerability was discovered in Perl. When there are non-ASCII bytes in the left-hand-side of the `tr` operator, `S_do_trans_invmap` can overflow the destination pointer `d`. $ perl -e '$_ = "\x{FF}" x 1000000; tr/\xFF/\x{100}/;' Segmentation fault (core dumped) It is believed that this vulnerability can enable Denial of Service and possibly Code Execution attacks on platforms that lack sufficient defenses.
- https://github.com/Perl/perl5/commit/87f42aa0e0096e9a346c9672aa3a0bd3bef8c1dd.patch
- https://metacpan.org/release/SHAY/perl-5.38.4/changes
- https://metacpan.org/release/SHAY/perl-5.40.2/changes
- http://www.openwall.com/lists/oss-security/2025/04/13/3
- http://www.openwall.com/lists/oss-security/2025/04/13/4
Perl threads have a working directory race condition where file operations may target unintended paths. If a directory handle is open at thread creation, the process-wide current working directory is temporarily changed in order to clone that handle for the new thread, which is visible from any third (or more) thread already running. This may lead to unintended operations such as loading code or accessing files from unexpected locations, which a local attacker may be able to exploit. The bug was introduced in commit 11a11ecf4bea72b17d250cfb43c897be1341861e and released in Perl version 5.13.6
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1098226
- https://github.com/Perl/perl5/commit/11a11ecf4bea72b17d250cfb43c897be1341861e
- https://github.com/Perl/perl5/commit/918bfff86ca8d6d4e4ec5b30994451e0bd74aba9.patch
- https://github.com/Perl/perl5/issues/10387
- https://github.com/Perl/perl5/issues/23010
- https://perldoc.perl.org/5.14.0/perl5136delta#Directory-handles-not-copied-to-threads
- https://www.openwall.com/lists/oss-security/2025/05/22/2
- http://www.openwall.com/lists/oss-security/2025/05/23/1
- http://www.openwall.com/lists/oss-security/2025/05/30/4
Perl for Windows relies on the system path environment variable to find the shell (cmd.exe). When running an executable which uses Windows Perl interpreter, Perl attempts to find and execute cmd.exe within the operating system. However, due to path search order issues, Perl initially looks for cmd.exe in the current working directory. An attacker with limited privileges can exploit this behavior by placing cmd.exe in locations with weak permissions, such as C:\ProgramData. By doing so, when an administrator attempts to use this executable from these compromised locations, arbitrary code can be executed.
(1) cpan/Archive-Tar/bin/ptar, (2) cpan/Archive-Tar/bin/ptardiff, (3) cpan/Archive-Tar/bin/ptargrep, (4) cpan/CPAN/scripts/cpan, (5) cpan/Digest-SHA/shasum, (6) cpan/Encode/bin/enc2xs, (7) cpan/Encode/bin/encguess, (8) cpan/Encode/bin/piconv, (9) cpan/Encode/bin/ucmlint, (10) cpan/Encode/bin/unidump, (11) cpan/ExtUtils-MakeMaker/bin/instmodsh, (12) cpan/IO-Compress/bin/zipdetails, (13) cpan/JSON-PP/bin/json_pp, (14) cpan/Test-Harness/bin/prove, (15) dist/ExtUtils-ParseXS/lib/ExtUtils/xsubpp, (16) dist/Module-CoreList/corelist, (17) ext/Pod-Html/bin/pod2html, (18) utils/c2ph.PL, (19) utils/h2ph.PL, (20) utils/h2xs.PL, (21) utils/libnetcfg.PL, (22) utils/perlbug.PL, (23) utils/perldoc.PL, (24) utils/perlivp.PL, and (25) utils/splain.PL in Perl 5.x before 5.22.3-RC2 and 5.24 before 5.24.1-RC2 do not properly remove . (period) characters from the end of the includes directory array, which might allow local users to gain privileges via a Trojan horse module under the current working directory.
- https://perldoc.perl.org/5.24.1/perldelta
- http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00002.html
- http://perl5.git.perl.org/perl.git/commit/cee96d52c39b1e7b36e1c62d38bcd8d86e9a41ab
- http://www.debian.org/security/2016/dsa-3628
- http://www.nntp.perl.org/group/perl.perl5.porters/2016/07/msg238271.html
- http://www.securityfocus.com/bid/92136
- http://www.securitytracker.com/id/1036440
- https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
- https://lists.apache.org/thread.html/7f6a16bc0fd0fd5e67c7fd95bd655069a2ac7d1f88e42d3c853e601c%40%3Cannounce.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2018/11/msg00016.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2FBQOCV3GBAN2EYZUM3CFDJ4ECA3GZOK/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DOFRQWJRP2NQJEYEWOMECVW3HAMD5SYN/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TZBNQH3DMI7HDELJAZ4TFJJANHXOEDWH/
- https://rt.perl.org/Public/Bug/Display.html?id=127834
- https://security.gentoo.org/glsa/201701-75
- https://security.gentoo.org/glsa/201812-07
- http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00002.html
- http://perl5.git.perl.org/perl.git/commit/cee96d52c39b1e7b36e1c62d38bcd8d86e9a41ab
- http://www.debian.org/security/2016/dsa-3628
- http://www.nntp.perl.org/group/perl.perl5.porters/2016/07/msg238271.html
- http://www.securityfocus.com/bid/92136
- http://www.securitytracker.com/id/1036440
- https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
- https://lists.apache.org/thread.html/7f6a16bc0fd0fd5e67c7fd95bd655069a2ac7d1f88e42d3c853e601c%40%3Cannounce.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2018/11/msg00016.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2FBQOCV3GBAN2EYZUM3CFDJ4ECA3GZOK/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DOFRQWJRP2NQJEYEWOMECVW3HAMD5SYN/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TZBNQH3DMI7HDELJAZ4TFJJANHXOEDWH/
- https://rt.perl.org/Public/Bug/Display.html?id=127834
- https://security.gentoo.org/glsa/201701-75
- https://security.gentoo.org/glsa/201812-07
NAME
IPC::Open2 - open a process for both reading and writing using open2()
SYNOPSIS
use IPC::Open2;
$pid = open2(\*CHLD_OUT, \*CHLD_IN, 'some cmd and args');
# or without using the shell
$pid = open2(\*CHLD_OUT, \*CHLD_IN, 'some', 'cmd', 'and', 'args');
# or with handle autovivification
my($chld_out, $chld_in);
$pid = open2($chld_out, $chld_in, 'some cmd and args');
# or without using the shell
$pid = open2($chld_out, $chld_in, 'some', 'cmd', 'and', 'args');
waitpid( $pid, 0 );
my $child_exit_status = $? >> 8;
DESCRIPTION
The open2() function runs the given $cmd and connects $chld_out for reading and $chld_in for writing. It's what you think should work when you try
$pid = open(HANDLE, "|cmd args|");
The write filehandle will have autoflush turned on.
If $chld_out is a string (that is, a bareword filehandle rather than a glob or a reference) and it begins with >&, then the child will send output directly to that file handle. If $chld_in is a string that begins with <&, then $chld_in will be closed in the parent, and the child will read from it directly. In both cases, there will be a dup(2) instead of a pipe(2) made.
If either reader or writer is the null string, this will be replaced by an autogenerated filehandle. If so, you must pass a valid lvalue in the parameter slot so it can be overwritten in the caller, or an exception will be raised.
open2() returns the process ID of the child process. It doesn't return on failure: it just raises an exception matching /^open2:/. However, exec failures in the child are not detected. You'll have to trap SIGPIPE yourself.
open2() does not wait for and reap the child process after it exits. Except for short programs where it's acceptable to let the operating system take care of this, you need to do this yourself. This is normally as simple as calling waitpid $pid, 0 when you're done with the process. Failing to do this can result in an accumulation of defunct or "zombie" processes. See "waitpid" in perlfunc for more information.
This whole affair is quite dangerous, as you may block forever. It assumes it's going to talk to something like bc, both writing to it and reading from it. This is presumably safe because you "know" that commands like bc will read a line at a time and output a line at a time. Programs like sort that read their entire input stream first, however, are quite apt to cause deadlock.
The big problem with this approach is that if you don't have control over source code being run in the child process, you can't control what it does with pipe buffering. Thus you can't just open a pipe to cat -v and continually read and write a line from it.
The IO::Pty and Expect modules from CPAN can help with this, as they provide a real tty (well, a pseudo-tty, actually), which gets you back to line buffering in the invoked command again.
WARNING
The order of arguments differs from that of open3().
SEE ALSO
See IPC::Open3 for an alternative that handles STDERR as well. This function is really just a wrapper around open3().
Module Install Instructions
To install vars, copy and paste the appropriate command in to your terminal.
cpanm vars
perl -MCPAN -e shell
install vars
For more information on module installation, please visit the detailed CPAN module installation guide.