I wasn't entirely sure if the output in 'env --debug' should be
quoted, so I left it out of this patch. Certainly it would look a bit
strange with the messages for 'env --split-string'.
-- 8< --
* doc/coreutils.texi (printenvAlwaysQuoted): New macro.
(printenv invocation): Use it.
(env invocation): Use it.
* src/printenv.h: New file.
* src/local.mk (noinst_HEADERS): Add it.
(src_env_SOURCES): Likewise. Group with src_printenv_SOURCES.
(src_printenv_SOURCES): New variable.
* src/printenv.c: Include argmatch.h and printenv.h.
(main): Quote printed variable names and values.
* src/env.c: Include argmatch.h and printenv.h.
(main): Quote printed variable names and values.
* tests/misc/printenv.sh: Add test cases.
* tests/env/env.sh: Likewise. Adjust invalid UTF-8 test cases.
* NEWS: Mention the improvement.
---
NEWS | 4 ++++
doc/coreutils.texi | 11 ++++++++++
src/env.c | 25 ++++++++++++++++++----
src/local.mk | 5 ++++-
src/printenv.c | 28 ++++++++++++++++++------
src/printenv.h | 48 ++++++++++++++++++++++++++++++++++++++++++
tests/env/env.sh | 42 ++++++++++++++++++++++++++++++------
tests/misc/printenv.sh | 34 ++++++++++++++++++++++++++++++
8 files changed, 180 insertions(+), 17 deletions(-)
create mode 100644 src/printenv.h
diff --git a/NEWS b/NEWS
index a85b0ada9..ac6184481 100644
--- a/NEWS
+++ b/NEWS
@@ -81,6 +81,10 @@ GNU coreutils NEWS -*-
outline -*-
'df', 'du', 'ls', 'od', 'pr', and 'sort' now escape invalid arguments in
error
messages for options expecting an integer.
+ 'env' and 'printenv' now quote printed environment variables in shell-escape
+ style. This avoids printing arbitrary data to the terminal and allows the
+ output to be sourced by a POSIX shell.
+
'install -C' will now avoid updating file metadata when the destination
already has the appropriate ownership and permissions.
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 939b0ccae..769f1930c 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -15514,6 +15514,15 @@ @node printenv invocation
@end table
+@macro printenvAlwaysQuoted
+The printed environment variables and their values are quoted using the
+@samp{shell-escape} style. The environment variable
+@env{QUOTING_STYLE} specifies the quoting style. Valid quoting styles
+are:
+@quotingStyles
+@end macro
+@printenvAlwaysQuoted
+
@cindex exit status of @command{printenv}
Exit status:
@@ -17477,6 +17486,8 @@ @node env invocation
specifications, the resulting environment is printed. This is like
specifying the @command{printenv} program.
+@printenvAlwaysQuoted
+
For some examples, suppose the environment passed to @command{env}
contains @samp{LOGNAME=rms}, @samp{EDITOR=emacs}, and
@samp{PATH=.:/gnubin:/hacks}:
diff --git a/src/env.c b/src/env.c
index ea7ff7067..3433db83b 100644
--- a/src/env.c
+++ b/src/env.c
@@ -23,8 +23,10 @@
#include <c-ctype.h>
#include <signal.h>
+#include "argmatch.h" /* argmatch($QUOTING_STYLE). */
#include "system.h"
#include "operand2sig.h"
+#include "printenv.h"
#include "quote.h"
#include "sig2str.h"
@@ -842,6 +844,22 @@ main (int argc, char **argv)
++optind;
}
+ bool quote_output = false;
+
+ /* Get the value from QUOTING_STYLE before unsetting environment
+ variables. */
+ if (!opt_nul_terminate_output)
+ {
+ int qs = getenv_quoting_style ();
+ if (qs < 0)
+ qs = shell_escape_quoting_style;
+ if (qs != literal_quoting_style)
+ {
+ set_quoting_style (NULL, qs);
+ quote_output = true;
+ }
+ }
+
if (ignore_environment)
{
devmsg ("cleaning environ\n");
@@ -887,12 +905,11 @@ main (int argc, char **argv)
if (! program_specified)
{
+ char const terminator = opt_nul_terminate_output ? '\0' : '\n';
+
/* Print the environment and exit. */
for (char *const *e = environ; *e; ++e)
- {
- fputs (*e, stdout);
- putchar (opt_nul_terminate_output ? '\0' : '\n');
- }
+ print_envvar (*e, terminator, quote_output);
return EXIT_SUCCESS;
}
diff --git a/src/local.mk b/src/local.mk
index db86cb5ea..cf13f1339 100644
--- a/src/local.mk
+++ b/src/local.mk
@@ -58,6 +58,7 @@ noinst_HEADERS = \
src/ls.h \
src/octhexdigits.h \
src/operand2sig.h \
+ src/printenv.h \
src/prog-fprintf.h \
src/remove.h \
src/set-fields.h \
@@ -398,7 +399,6 @@ src_cp_SOURCES = src/cp.c $(copy_sources) $(selinux_sources)
src_date_SOURCES = src/date.c src/show-date.c
src_dir_SOURCES = src/ls.c src/ls-dir.c
src_du_SOURCES = src/du.c src/show-date.c
-src_env_SOURCES = src/env.c src/operand2sig.c
src_vdir_SOURCES = src/ls.c src/ls-vdir.c
src_id_SOURCES = src/id.c src/group-list.c
src_groups_SOURCES = src/groups.c src/group-list.c
@@ -421,6 +421,9 @@ src_rmdir_SOURCES = src/rmdir.c src/prog-fprintf.c
src_mkfifo_SOURCES = src/mkfifo.c $(selinux_sources)
src_mknod_SOURCES = src/mknod.c $(selinux_sources)
+src_env_SOURCES = src/env.c src/operand2sig.c src/printenv.h
+src_printenv_SOURCES = src/printenv.c src/printenv.h
+
src_df_SOURCES = src/df.c src/find-mount-point.c
src_stat_SOURCES = src/stat.c src/find-mount-point.c
diff --git a/src/printenv.c b/src/printenv.c
index c2b1c69cd..fbe35d5a6 100644
--- a/src/printenv.c
+++ b/src/printenv.c
@@ -32,7 +32,9 @@
#include <sys/types.h>
#include <getopt.h>
+#include "argmatch.h" /* argmatch($QUOTING_STYLE). */
#include "system.h"
+#include "printenv.h"
/* Exit status for syntax errors, etc. */
enum { PRINTENV_FAILURE = 2 };
@@ -107,14 +109,27 @@ main (int argc, char **argv)
}
}
+ bool quote_output = false;
+
+ if (!opt_nul_terminate_output)
+ {
+ int qs = getenv_quoting_style ();
+ if (qs < 0)
+ qs = shell_escape_quoting_style;
+ if (qs != literal_quoting_style)
+ {
+ set_quoting_style (NULL, qs);
+ quote_output = true;
+ }
+ }
+
bool ok;
+ char const terminator = opt_nul_terminate_output ? '\0' : '\n';
+
if (optind >= argc)
{
for (char **env = environ; *env != NULL; ++env)
- {
- fputs (*env, stdout);
- putchar (opt_nul_terminate_output ? '\0' : '\n');
- }
+ print_envvar (*env, terminator, quote_output);
ok = true;
}
else
@@ -137,8 +152,9 @@ main (int argc, char **argv)
{
if (*ep == '=' && *ap == '\0')
{
- fputs (ep + 1, stdout);
- putchar (opt_nul_terminate_output ? '\0' : '\n');
+ char const *val = ep + 1;
+ fputs (quote_output ? quoteN (val) : val, stdout);
+ putchar (terminator);
matched = true;
break;
}
diff --git a/src/printenv.h b/src/printenv.h
new file mode 100644
index 000000000..ce12ef44a
--- /dev/null
+++ b/src/printenv.h
@@ -0,0 +1,48 @@
+/* Common definitions for 'printenv' and 'env'
+ Copyright (C) 2026 Free Software Foundation, Inc.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+#ifndef PRINTENV_H
+# define PRINTENV_H 1
+
+static inline void
+print_envvar (char const *entry, char terminator, bool quoted)
+{
+ if (! quoted)
+ fputs (entry, stdout);
+ else
+ {
+ idx_t const entry_len = strlen (entry);
+ char const *equal = memchr (entry, '=', entry_len);
+
+ /* If the parent process manipulates ENVIRON directly, it is possible
+ that an entry does not contain an equal sign. */
+ idx_t const var_len = equal ? equal - entry : entry_len;
+ fputs (quoteN_mem (entry, var_len), stdout);
+
+ if (equal)
+ {
+ putchar ('=');
+ char const *val = equal + 1;
+ idx_t const val_len = entry_len - (val - entry);
+ /* Prefer "VAR=" over "VAR=''". */
+ if (0 < val_len)
+ fputs (quoteN_mem (val, val_len), stdout);
+ }
+ }
+ putchar (terminator);
+}
+
+#endif
diff --git a/tests/env/env.sh b/tests/env/env.sh
index 425a82724..a4cc00598 100755
--- a/tests/env/env.sh
+++ b/tests/env/env.sh
@@ -91,12 +91,19 @@ EOF
compare exp out || fail=1
# env shouldn't care what encoding name or value is
-for nv in 'NON_UTF8_TEST=\240' 'NON_UTF8_TEST\240=1'; do
- env $(printf "$nv") env > all || fail=1
- grep '^NON_UTF8_TEST' all | LC_ALL=C sort > out || framework_failure_
- printf "$nv\\n" > exp || framework_failure_
- compare exp out || fail=1
-done
+cat <<\EOF >exp || framework_failure_
+NON_UTF8_TEST=''$'\240'
+EOF
+env $(printf 'NON_UTF8_TEST=\240') env > all || fail=1
+grep '^NON_UTF8_TEST' all | LC_ALL=C sort > out || framework_failure_
+compare exp out || fail=1
+
+cat <<\EOF >exp || framework_failure_
+'NON_UTF8_TEST'$'\240'=1
+EOF
+env $(printf 'NON_UTF8_TEST\240=1') env > all || fail=1
+grep "^'NON_UTF8_TEST" all | LC_ALL=C sort > out || framework_failure_
+compare exp out || fail=1
# PATH modifications affect exec.
mkdir unlikely_name || framework_failure_
@@ -186,4 +193,27 @@ EOF
compare err_exp err || fail=1
done
+# QUOTING_STYLE affects redirected output.
+cat <<\EOF >exp-noargs-literal || framework_failure_
+a b=c d
+EOF
+cat <<\EOF >exp-noargs-shell || framework_failure_
+'a b'='c d'
+EOF
+tr "'" '"' <exp-noargs-shell >exp-noargs-c || framework_failure_
+for qs in literal shell c; do
+ env -i PATH="$PATH" QUOTING_STYLE=$qs 'a b'='c d' \
+ env >out-t 2>err || fail=1
+ grep -vE 'QUOTING_STYLE|PATH' out-t > out || framework_failure_
+ compare exp-noargs-$qs out || fail=1
+ compare /dev/null err || fail=1
+done
+
+# Check the behavior with an invalid value for QUOTING_STYLE.
+printf 'env: ignoring invalid value of environment variable %s\n' \
+ "QUOTING_STYLE: 'invalid'" >exp || framework_failure_
+env QUOTING_STYLE=invalid env >out 2>err || fail=1
+grep '^QUOTING_STYLE=invalid$' out || fail=1
+compare exp err || fail=1
+
Exit $fail
diff --git a/tests/misc/printenv.sh b/tests/misc/printenv.sh
index f146d46b2..0cb90681e 100755
--- a/tests/misc/printenv.sh
+++ b/tests/misc/printenv.sh
@@ -80,4 +80,38 @@ compare exp out || fail=1
returns_ 1 env a=b=c printenv a=b > out || fail=1
compare /dev/null out || fail=1
+# QUOTING_STYLE affects redirected output.
+cat <<\EOF >exp-noargs-literal || framework_failure_
+a b=c d
+EOF
+cat <<\EOF >exp-args-literal || framework_failure_
+c d
+EOF
+cat <<\EOF >exp-noargs-shell || framework_failure_
+'a b'='c d'
+EOF
+cat <<\EOF >exp-args-shell || framework_failure_
+'c d'
+EOF
+tr "'" '"' <exp-noargs-shell >exp-noargs-c || framework_failure_
+tr "'" '"' <exp-args-shell >exp-args-c || framework_failure_
+for qs in literal shell c; do
+ env -i PATH="$PATH" QUOTING_STYLE=$qs 'a b'='c d' \
+ printenv >out-t 2>err || fail=1
+ grep -vE 'QUOTING_STYLE|PATH' out-t > out || framework_failure_
+ compare exp-noargs-$qs out || fail=1
+ compare /dev/null err || fail=1
+ env -i PATH="$PATH" QUOTING_STYLE=$qs 'a b'='c d' \
+ printenv 'a b' >out 2>err || fail=1
+ compare exp-args-$qs out || fail=1
+ compare /dev/null err || fail=1
+done
+
+# Check the behavior with an invalid value for QUOTING_STYLE.
+printf 'printenv: ignoring invalid value of environment variable %s\n' \
+ "QUOTING_STYLE: 'invalid'" >exp || framework_failure_
+env QUOTING_STYLE=invalid printenv >out 2>err || fail=1
+grep '^QUOTING_STYLE=invalid$' out || fail=1
+compare exp err || fail=1
+
Exit $fail
--
2.55.0
