如何使脚本独立于执行位置

Question

I am running into the problem of commands failing because I expect them to be executed at some directory and that is not the case.

For example I want to do:

pdfcrop --margins '0 0 -390 0' $pag "$pag"_1stCol.pdf

to create a new pdf document, and then

mv `\ls /home/dir | grep '_1stCol'` /home/gmanglano/dir/columns

The problem is that the mv command is failing because it finds the document, it is trying to move that file found FROM the directory where I executed the script, not from where it was found.

This is happening to me somewhat often and I feel there is a concept I am missing or I am thinking this the wrong way arround.

The error I get is:

mv: cannot stat '1stCol.pdf': No such file or directory

When there is, in fact, said fail, it just is not in the directory I launched the script.

Answer 1

Instead of monkeying with ls and backticks and all that, just use the find command. It's built for to find files and then execute a command based on the results of that find:

 find /home/dir -name "*_1stCol.pdf" -exec mv {} /home/gmanglano/dir/columns \;

This is finding files in /home/dir that match the name *_1stCol.pdf and then moves them. The {} is the token for the found file.

Answer 2

Don't parse the output of ls : if you simplify the mv command to

mv /home/dir/*_1stCol.pdf /home/gmanglano/dir/columns

then you won't have an issue with being in the wrong directory.