Extracting all JavaScript filenames from a log file using bash script


I have 4 different named log files, all with txt extensions. I need to write a bash script file that extracts JavaScript file names from any of these log files regardless of their names. The output of the script should not include the path, have to be unique, and sorted

After some research I came up with this:

cat logfile1.txt | grep '[^.(]*\.js' | awk -F " " '{print $7}' | sort | uniq -c| sort -nr

This code does only haft the job;

  • PRO: It does extract any JS, sorts it, and gives unique results.
  • CON: I need this in a file.sh not a command line as, it is now. Also, I’m getting the entire path to the JS file. I only need the file name jquery.js

I tried adding grep -v "*/name-of-path-before-JS" to block the result from giving me the full path but that isn’t working.

I found someone who made something kind of similar using python;

filenames = set()

with open(r"/home/filelog.txt") as f:
    for line in f:
        end = line.rfind(".js") + 3 # 3 = len(".js")
        start = line.rfind("/", 0, end) + 1 # 1 = len("/")
        filename = line[start:end]
        if filename.endswith(".js"):

for filename in sorted(filenames, key=str.lower):

Although is missing the sort and uniq options when giving the output it does give the results by only putting out filename.js and not the whole path as the command line I made. Also, I to add the path to the log.txt file while running the script and not just appended it as in the python script below.

$./LogReaderScript.sh File-log.txt


Would you please try the shell script LogReaderScript.sh:


if [[ $# -eq 0 ]]; then                 # if no filenames are given
    echo "usage: $0 logfile .."         # then show the usage and abort
    exit 1

grep -hoE "[^/]+\.js" "[email protected]" | sort | uniq -c | sort -nr

By setting the file as executable with chmod +x LogReaderScript.sh,
you can invoke:

./LogReaderScript.sh File-log.txt

If you want to process multiple files at a time, you can also say something

./LogReaderScript.sh *.txt
  • -o option to grep tells grep to print the matched substrings only,
    instead of printing the matched line.
  • -E option specifies extended regex as a pettern.
  • -h option suppresses the prefixed filenames on the output if multiple
    files are given.
  • The pattern (regex) [^/]+\.js matches a sequence of any characters
    other than a slash, and followed by a extention .js. It will match
    the target filenames.
  • "[email protected]" is expanded to the filename(s) passed as arguments to the script.

Answered By – tshiono

This Answer collected from stackoverflow, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0

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