is my crontab syntax invalid?

Question

simple question:

10 4 * * * rm -rf ~/code/rehlds/build/ && ~/code/rehlds/build.sh --compiler=gcc --jobs=4 > /dev/null 2>&1

I checked an there is no /build folder which indicates that the build.sh did not execute.

crontab -e

10 4 * * * rm -rf ~/code/rehlds/build/ && ~/code/rehlds/build.sh --compiler=gcc --jobs=4 > /dev/null 2>&1

pgrep cron 658 1232359

so here I can see it was run sudo grep CRON /var/log/syslog Dec 8 04:10:01 xxxx CRON[1190963]: (xxx) CMD (rm -rf ~/code/rehlds/build/ && ~/code/rehlds/build.sh --compiler=gcc --jobs=4 > /dev/null 2>&1)

my job ran, but no compiling, that cronlog file is empty.

CMD (./code/rehlds/build.sh --compiler=gcc --jobs=4 &> ./cronlog)

With all output redirected to/dev/null there most probably are no logs. — Gerald Schneider, Dec 08 '22 at 11:53
10 4 * * * rm -rf ~/code/rehlds/build/ && ~/code/rehlds/build.sh --compiler=gcc --jobs=4 > ~somelog like this? will it create this somelog if not existing? — eetzt, Dec 08 '22 at 11:59
No, use something like: >/full/path/log 2> /full/path/err to generate log for STDOUT and for STDERR. And use absolute paths — Romeo Ninov, Dec 08 '22 at 12:08
not even this works for 5min * * * * * touch ./testfile &> ./testlog — eetzt, Dec 08 '22 at 12:32
ok now i found out that if you are working with 2 bash sessions and save in nano, then the file is not written, only if you close it... — eetzt, Dec 08 '22 at 12:44
Does this answer your question? Why is my crontab not working, and how can I troubleshoot it? — diya, Dec 08 '22 at 12:50
why does this log output not work? somecmd > ~/rehldslog 2>&1. in the logs i can see (CRON) info (No MTA installed, discarding output) and somecmd did not run — eetzt, Dec 10 '22 at 12:31

eetzt · Answer 1 · 2022-12-08T13:14:05.383

if you work with 2 bash session, you must not only save the file with nano, but close it, only then is the crontab added.
when executing the build.sh I must first cd into that directory otherwise error:

$ ./code/rehlds/build.sh --compiler=gcc --jobs=4 CMake Error: The source directory "/home/cs2" does not appear to contain CMakeLists.txt. Specify --help for usage, or press the help button on the CMake GUI. make: *** No targets specified and no makefile found. Stop.

I found that out by manually executing this command

correct command:

10 4 * * * cd ./code/rehlds && rm -rf ./build && ./build.sh --compiler=gcc --jobs=4 > /dev/null 2>&1

is my crontab syntax invalid?

1 Answers1