Using CAT command read all file content recursively for paths file-CodePudding

So I've a file called allTextFiles.txt in which it has paths of a all regular text file.

eg:
./test/file1.txt
./test/file2.txt
./test/file3.txt

My task is to formulate shell command such that command CAT will go through all of these paths and display content of each file.
Is it possible ?

CodePudding user response：

Using xargs with the allTextFiles.txt

You can use the command cat to list the content and xargs (Xargs command documentation) to process every line of the file. For example:

cat allTextFiles.txt | xargs cat
kk #./test/file1.txt
jj #./test/file2.txt
yy #./test/file3.txt

Using find command without allTextFiles.txt

You can use the command find (find command documentation) to go trough the main folder and search recursively. Once you find a file, to use the cat command.

You achieve the purpose of showing all the content of txt files recursively with only one command.

find . -type f -name "*.txt" -exec cat {} \;
kk #./test/file1.txt
jj #./test/file2.txt
yy #./test/file3.txt

Where the . means current directory. -type f only filters files. -name "*.txt" filters only files ending with .txt extension and the -exec part is where you process all the files found.

Does it cover your need?

CodePudding user response：

You can use a loop; something like

while IFS= read -r file; do
    cat "$file"
done < allTextFiles.txt

See Bash FAQ 001 for more discussion on reading a file a line at a time (Much of the content applies to all shells, not just bash).

If you are using bash:

readarray -t files < allTextFiles.txt
cat "${files[@]}"

is an alternative that avoids the explicit loop.