PDL in abinitio

There is command like this on the graph's parameter. I could not figure it out. It prints nothing.In abinitio help page, I could not find what -f means as well, thats why I am here.Could you please help me to understand it

$([ -f $FILE_PATH/$SUBJECT_AREA_X/`echo "$FILE_PATTERN_X" | awk -v RUNDATE=$RUN_DATE -F'_' '{for(i=1; i<=NF-1;i++) { printf "%s%s",$i, FS} { printf "%s%s\n", RUNDATE, substr($NF,length(RUNDATE)+1,length($NF)) }}'` ]


  • ([ -f ... ]): This is a conditional expression that checks if a file exists. The -f flag is used to test whether the given path corresponds to a regular file.

    $FILE_PATH/$SUBJECT_AREA_X/...: This part of the command is constructing the path to the file. It seems to involve variables like $FILE_PATH and $SUBJECT_AREA_X to define the directory structure.

    echo "$FILE_PATTERN_X" | awk -v RUNDATE=$RUN_DATE -F'_' '...awk command...': This part uses the awk command to process the contents of $FILE_PATTERN_X. It splits the input on underscores (-F'_'), and then it reconstructs the filename by appending the $RUN_DATE variable to the second-to-last field (excluding the last field, assumed to be a date-related part).

    The entire awk command is encapsulated in backticks (``), which means the output of this awk command is substituted into the overall command.

    The resulting constructed file path and name are used as an argument to the -f test in the [ ] conditional expression.