From fd977388a265b1c4e3199f0ba7880986fb9d089a Mon Sep 17 00:00:00 2001 From: Martijn Dekker Date: Tue, 1 Sep 2020 08:11:27 +0100 Subject: [PATCH] -o posix: allow invoked programs to inherit FDs > 2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If there are file descriptors > 2 opened with 'exec' or 'redirect', ksh93 has always closed them when invoking another pogram. This is contrary to POSIX which states: Utilities other than the special built-ins […] shall be invoked in a separate environment that consists of the following. The initial value of these objects shall be the same as that for the parent shell, except as noted below. * Open files inherited on invocation of the shell, open files controlled by the exec special built-in plus any modifications, and additions specified by any redirections to the utility * […] https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_12 src/cmd/ksh93/sh/io.c: sh_redirect(): - When flag==2, do not close FDs > 2 if POSIX mode is active. src/cmd/ksh93/tests/io.sh: - Regress-test inheriting FD 7 with and without POSIX mode. src/cmd/ksh93/sh.1: - Update. --- NEWS | 1 + src/cmd/ksh93/sh.1 | 4 +++- src/cmd/ksh93/sh/io.c | 2 +- src/cmd/ksh93/tests/io.sh | 8 ++++++++ 4 files changed, 13 insertions(+), 2 deletions(-) diff --git a/NEWS b/NEWS index 4c3a1caa38d0..003ea1148ffa 100644 --- a/NEWS +++ b/NEWS @@ -16,6 +16,7 @@ Any uppercase BUG_* names are modernish shell bug IDs. * disables the &> redirection shorthand * causes the 'let' arithmetic command to recognise octal numbers by leading zeros regardless of the setting of the 'letoctal' option + * causes file descriptors > 2 to be left open when invoking another program 2020-08-19: diff --git a/src/cmd/ksh93/sh.1 b/src/cmd/ksh93/sh.1 index a45891ca6316..9e5bfcd3a252 100644 --- a/src/cmd/ksh93/sh.1 +++ b/src/cmd/ksh93/sh.1 @@ -6817,7 +6817,8 @@ command. Any file descriptor numbers greater than .B 2 that are opened with this mechanism are closed when invoking another program, -unless explicitly redirected to themselves as part of that invocation. +unless they are explicitly redirected to themselves as part of that invocation +(e.g. \fb4>&4\fR) or the \fBposix\fR shell option is active. .TP \(dg \f3return\fP \*(OK \f2n\^\fP \*(CK Causes a shell @@ -7038,6 +7039,7 @@ to fail or zero if no command has failed. .B posix Enable POSIX standard compatibility mode. This option is on by default if ksh is invoked as \fBsh\fR. It +causes file descriptors > 2 to be left open when invoking another program, enables octal numbers in \fBlet\fR shell arithmetic (see \fBletoctal\fR), and disables the \fB&>\fR redirection shorthand. .TP 8 diff --git a/src/cmd/ksh93/sh/io.c b/src/cmd/ksh93/sh/io.c index 179bd3f88f29..4c7ef034d89f 100644 --- a/src/cmd/ksh93/sh/io.c +++ b/src/cmd/ksh93/sh/io.c @@ -1094,7 +1094,7 @@ int sh_redirect(Shell_t *shp,struct ionod *iop, int flag) Namval_t *np=0; int isstring = shp->subshell?(sfset(sfstdout,0,0)&SF_STRING):0; - if(flag==2) + if(flag==2 && !sh_isoption(SH_POSIX)) clexec = 1; if(iop) traceon = sh_trace(shp,NIL(char**),0); diff --git a/src/cmd/ksh93/tests/io.sh b/src/cmd/ksh93/tests/io.sh index f2c53ee14dbd..f703e2c4a059 100755 --- a/src/cmd/ksh93/tests/io.sh +++ b/src/cmd/ksh93/tests/io.sh @@ -616,5 +616,13 @@ then set -o posix [[ $(< aha2.txt) == ok2 ]] || err_exit '&> does not redirect stderr' fi +# In POSIX mode, file descriptors > 2 should remain open when invoking another proram +if [[ -o ?posix ]] +then (set -o posix; exec 7>ok.txt; "$SHELL" -c 'print ok >&7' 2>/dev/null) + [[ $( 2 not inherited in POSIX mode' +fi +(exec 7>bad.txt; "$SHELL" -c 'print bad >&7' 2>/dev/null) +[[ $( 2 inherited without POSIX mode' "(got $actual)" + # ====== exit $((Errors<125?Errors:125))