Shell Programming and Scripting

Try this and remove echowhen happy:

Code:

for FN in $(grep -Eli "can.t|cannot|cancelled" *.txt); do NFN=$(grep id $FN); echo mv $FN ${NFN#id*:*}.can.txt;  done
mv a1.txt 73254.can.txt
mv c3.txt 3467.can.txt

I thought I had something ready a lot sooner, until I noticed with your new data that the input file format had changed. (There were no spaces in the id line in your first sample file; but in message #7 in this thread there is a space before the colon and sometimes a space after the colon.) These possible solutions might not be optimal. They were originally designed to create a list of files as you requested in message #4 in this thread.

Your specification still isn't clear as to whether all of the files to be processed are in a single directory or if they are somewhere in the file hierarchy rooted in a given directory. Both of these assume that you only want to process files with names ending in .txt in the current working directory. (If you want to work on all files in the file hierarchy rooted in the current directory we can simplify the find proposal to do that.) Depending on what system you're using and the lengths of the names you're processing the suggestion using just grep may fail by exceeding ARG_MAX limitations. So, if the grep proposal fails, you can use the find proposal instead:

Code:

#!/bin/bash
printf "Proposal using just grep:\n"
grep -Eil "can't|cannot|cancelled" *.txt | while read -r file
do      new=$(sed -n 's/^id *: *//p' "$file")
        if [ -n "$new" ]
        then    echo mv "$file" "$new.can.txt"
        fi
done

printf "\nProposal using find and grep:\n"
find . \( ! -name . -type d -prune \) -o \
       \( -name '*.txt' -exec grep -Eil "can't|cannot|cancelled" {} + \) |
while read -r file
do      new="$(sed -n 's/^id *: *//p' "$file")"
        if [ -n "$new" ]
        then    echo mv "$file" "${file%/*}/$new.can.txt"
        fi
done

There are simpler way to make some versions of the find utility only report on files in the current directory. The proposal here should work on any system that supports the find features specified by the POSIX Standards and the Single UNIX Specifications.

Note that RudiC's proposal is a simpler way to do this, but will fail if the length of the list of filenames exceeds ARG_MAX or if a file contains one of the grepped for strings but does not contain a line starting with id followed by zero or more spaces followed by a colon. All of our proposals may fail in unspecified ways if one or your input files contains more than one line starting with id followed by zero or more spaces and a colon (for either of my proposals) and if one of your input files contains more than one line containing id anywhere (for RudiC's proposal).