grep (or something else) for a string with a subdirectory?-CodePudding

I'm contending with messy system that employs a lot of bash scripts for most of its functions, and we found a bug I need to work around.

I figured that I can make it work by changing a variable, VAR1 that is set to A depending from where it loads files, but in order to do this, I need to make the system aware of when certain process has opened a file that is within a subdirectory, and then change the variable, since it has only two ways to load those files, either from a directory /var/system/folder/file.ext or from a subdirectory /var/system/folder/subfolder/file.ext.

so my assumption was, whatever, just do something like ....

if [ ps -aux | grep /var/system/folder/*/*.*]; then
VAR1=B

for example, or something to that effect, and that will make it display an output with the pathname from its command line arguments whenever it opens a file within that subfolder, and thus make it change the variable. But... for some reason, grep doesn't seem to work with wildcards, and I've been trying for a while but I couldn't figure out how to make this work. I'd really appreciate some help.

CodePudding user response：

I'm assuming you want to get the path depth, and the reason for wildcards was because the exact names are unknown in advance (otherwise just use them).

if
    LC_ALL=POSIX ps -fo args= aux |
    grep -E '[[:blank:]]/var/system/folder/[^/] /[^/] \.[^.] $' >/dev/null 2>&1
then
    VAR1=B
fi

. matches any character and must be escaped to be used literally.

You could change [[:blank:]] to cmd-name[[:blank:]] or similar (but allow for command line options etc). ^cmd-name.*/var/system..etc$ will match the start and end of a commandline. Commands may sometimes be invoked with a full path /path/cmd or ./cmd.

If you're on Linux, look at the inofify-tools package (inotifywait(1), inotifywatch(1)). You can use these to trigger commands when events such as access or modify happen for a file or files in a directory.

CodePudding user response：

Finally got it working! a version of what Jerry said was the effective solution.

function checksubdir {
ps -aux | grep " /var/system/folder/[^/]*/" | grep process
}

if checksubdir;
then
VAR1=B

made it produce an output whenever the process was opening a file from a subpath in /var/system/folder, with the second piping making it display ONLY this process and no additional outputs that would confuse the function. and then it changed the variable correctly.