What means echo"{@@##}"? We got a script that we need to understand, and at some point, we got this syntax: if [ "$PASS_CHAINE" = "TRUE" ] then echo "Launching DEGAGEMENT" | SLog cd $INTERFACE_D/bin_cm/deg $INTERFACE_D/bin_cm/deg/lance_deg 2>&1 ; echo "{@@##}RETURN_REAL_STATUS_SCRIPT=${?}" | SLog EXIT_CODE=$? if [ $EXIT_CODE -ne 0 ] then echo "Error in DEGAGEMENT" | SLog exit_script fi fi I'm confused about the `echo "{@@##}"` part, I don't really understand it. I know the scripts tries to test the return code of the `lance_deg` function, but it won't work because it's gonna get the return code of the echo command. I can remove the echo part to solve my problem, but the point is really to understand what the `{@@##}` part means.

That part:


echo "{@@##}RETURN_REAL_STATUS_SCRIPT=${?}"


Just prints:


{@@##}RETURN_REAL_STATUS_SCRIPT=x


where the last `x` is replaces by the value of variable `$?`. From the bash manpage:


? Expands to the exit status of the most recently executed foreground pipeline.


That means that `$?` contains the exit code of the previously executed command: `$INTERFACE_D/bin_cm/deg/lance_deg`, which can be a digit from `0`; for success and `1` or geather for an error.

See this:


$ ls file
file
$ echo $? # 0 indicates success
0
$ ls file_not_exist
ls: cannot access file_not_exist: No such file or directory
$ echo $? # >0 is an error
2