#2966 Issue `closed`: STDOUT_STDERR_FILE used but never defined - /rear.help.stdout_stderr file shouldn't be there¶

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schlomo opened issue at 2023-04-04 13:46:¶

I tried running fakeroot reat because I just wanted to check the help output and was surprised by the many error messages:

$ fakeroot usr/sbin/rear 
usr/sbin/rear: line 554: /rear.help.stdout_stderr: Permission denied
chmod: cannot access '/rear.help.stdout_stderr': No such file or directory
usr/sbin/rear: line 559: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
OS_VENDOR=Ubuntu
OS_VERSION=22.04
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
/home/schlomo/src/rear/usr/share/rear/lib/framework-functions.sh: line 45: /rear.help.stdout_stderr: Permission denied
Usage: rear [-h|--help] [-V|--version] [-dsSv] [-D|--debugscripts SET] [-c DIR] [-C CONFIG] [-r KERNEL] [--] COMMAND [ARGS...]

Relax-and-Recover comes with ABSOLUTELY NO WARRANTY; for details see
the GNU General Public License at: http://www.gnu.org/licenses/gpl.html

Available options:
 -h --help           usage information (this text)

It turns out that we use STDOUT_STDERR_FILE but it seems like we never set this variable
https://github.com/rear/rear/blob/ae9c64597d3b73112e8845e96ad1cb2ca40fac25/usr/share/rear/lib/framework-functions.sh#L45

Also, on my test system I find this file in /

[root@rear-ol8u7 ~]# ll /
total 32
lrwxrwxrwx.   1 root root    7  9. Okt 2021  bin -> usr/bin
dr-xr-xr-x.   5 root root 4096  5. Mär 03:26 boot
drwxr-xr-x.  19 root root 3320  3. Apr 14:17 dev
drwxr-xr-x. 150 root root 8192  3. Apr 20:49 etc
drwxr-xr-x.   3 root root   21 20. Feb 19:54 home
lrwxrwxrwx.   1 root root    7  9. Okt 2021  lib -> usr/lib
lrwxrwxrwx.   1 root root    9  9. Okt 2021  lib64 -> usr/lib64
drwxr-xr-x.   2 root root    6  9. Okt 2021  media
drwxr-xr-x.   2 root root    6  9. Okt 2021  mnt
drwxr-xr-x.   4 root root   49 20. Feb 20:18 opt
dr-xr-xr-x. 207 root root    0  3. Apr 14:17 proc
-rw-------.   1 root root  624  2. Apr 15:39 rear.help.stdout_stderr
drwxr-xr-x.   3 root root   17  5. Mär 21:38 rear-local
dr-xr-x---.   7 root root 4096  4. Apr 15:43 root
drwxr-xr-x.  39 root root 1220  3. Apr 14:19 run
lrwxrwxrwx.   1 root root    8  9. Okt 2021  sbin -> usr/sbin
drwxr-xr-x.   3 root root   18  3. Apr 20:56 src
drwxr-xr-x.   2 root root    6  9. Okt 2021  srv
dr-xr-xr-x.  13 root root    0  3. Apr 14:17 sys
drwxrwxrwt.  11 root root 4096  4. Apr 15:43 tmp
drwxr-xr-x.  13 root root  158 20. Feb 19:29 usr
drwxr-xr-x.  21 root root 4096 20. Feb 19:48 var

@jsmeix it seems like you worked on this in #2633, can you please have another look? Maybe some change broke that without anybody noticing it.

jsmeix commented at 2023-04-05 07:13:¶

With current GitHub master code I get

# find usr/sbin/rear usr/share/rear -type f | xargs grep 'STDOUT_STDERR_FILE='

usr/sbin/rear:
STDOUT_STDERR_FILE="/dev/null"
STDOUT_STDERR_FILE="$TMP_DIR/$PROGRAM.$WORKFLOW.stdout_stderr"

usr/share/rear/lib/_input-output-functions.sh:
# In non-debug modes stdout and stderr are redirected to STDOUT_STDERR_FILE="$TMP_DIR/rear.$WORKFLOW.stdout_stderr" if possible
# but in certain cases (e.g. for the 'help' workflow where no $TMP_DIR exists) STDOUT_STDERR_FILE=/dev/null

@schlomo
it seems in your special case $TMP_DIR is not set?

schlomo commented at 2023-04-05 16:55:¶

You are right and I failed to use my IDE... nevertheless we need to solve the problem of creating this file in /.

Yes, if TMP_DIR is not set then the following line silently gives a false positive:
https://github.com/rear/rear/blob/0093828651efe64407d51d4801aaba6fe4dee835/usr/sbin/rear#L549

because of this behaviour:

[root@rear-ol8u7 ~]# test -d $sfdkjashdkfjahfdjk && echo yes
yes
[root@rear-ol8u7 ~]#

And this is a case where quoting the variable (or checking it) would have helped:

[root@rear-ol8u7 ~]# test -d "$sfdkjashdkfjahfdjk" && echo yes
[root@rear-ol8u7 ~]#

The problem is actually specific to the help workflow because of this:
https://github.com/rear/rear/blob/0093828651efe64407d51d4801aaba6fe4dee835/usr/sbin/rear#L498-L513

I guess that we should do this basic setup also for the help workflow as the other ReaR code heavily relies on it.

jsmeix commented at 2023-04-06 10:56:¶

Via
https://github.com/rear/rear/commit/99110661fc75e243ccac308f0b12b11142999834
I fixed the test -d $TMP_DIR issue.

By the way:
The root cause of my buggy code was
that 'test' behaves inconsistent

# test && echo y || echo n
n
# test '' && echo y || echo n
n

# test -d && echo y || echo n
y
# test -d '' && echo y || echo n
n
#  test -e && echo y || echo n
y
#  test -e '' && echo y || echo n
n

depending on whether or not an operator is used and
it behaves "very inconsistent" when the '-a' and '-o'
operators are used as file operator versus as
so called (according to 'help test') "other operator":

# test -a '' -a -a '' && echo y || echo n
n
# test -a -a -a && echo y || echo n
y

# test -o '' -o -o '' && echo y || echo n
n
# test -o -o -o && echo y || echo n
y

jsmeix commented at 2023-04-06 11:08:¶

Regarding test "$WORKFLOW" != "help":

We have that four times in sbin/rear
in current GitHub master code at

# cat -n usr/sbin/rear | grep 'test.*WORKFLOW.*help'
   498  if test "$WORKFLOW" != "help" ; then
   575  if test "$WORKFLOW" != "help" ; then
   723          test "$WORKFLOW" != "help" && LogPrint "Saving $RUNTIME_LOGFILE as $LOGFILE"
   735  if test "$WORKFLOW" != "help" ; then

In the past I already had "a lot of (not so) fun"
with the special behaviour of the 'help' workflow.
The special behaviour of the 'help' workflow was
already there when I encountered ReaR for the first time.
In general I would appreciate it if we could make
the 'help' workflow behave more like the other workflows.

schlomo commented at 2023-04-08 19:09:¶

Yes, totally agree with you. What would happen if we simply remove the special treatment? Maybe it's not so bad?

schlomo commented at 2023-04-23 09:23:¶

@rear/contributors any thoughts on completely removing the special handling for the help workflow to simplify things?

github-actions commented at 2023-06-23 02:48:¶

Stale issue message

github-actions commented at 2023-08-24 02:00:¶