Bash Script - Command not recognized in while loop when getting input from file and parsing in it-CodePudding

I'm getting input from file and parsing it into 2 variable. But when I run the command, I guess something is wrong with space or smt else. The command works when when I run it manually.

I have checked so many entries but couldn't find the way to do. What could be the issue.

while read p; do
    echo "$p"
    CRT= echo -n "$p" | awk -F '/' '{print $6}'
    echo -n "$CRT"
    kubectl cp ns-mv/gen-0:$p /tmp/$CRT
done < test.txt

Here is the text.txt

[master]$ cat test.txt
/opt/gen/AughGEN/OutCSY/CRT-1154.trt
[master]$

So basically what I want is

kubectl cp ns-mv/gen-0:/opt/gen/AughGEN/OutCSY/CRT-1154.trt /tmp/CRT-1154.trt as a command

output

[master]$ bash test.sh
/opt/gen/AughGEN/OutCSY/CRT-1154.trt
CRT-1154.trt
tar: /opt/gen/AughGEN/OutCSY/CRT-1154.trt\r: Cannot stat: No such file or directory
tar: Exiting with failure status due to previous errors

CodePudding user response：

The problem is that your file has Windows-style CRLF line ends, and Bash does not recognize those on Linux.

This error message:

tar: /opt/gen/AughGEN/OutCSY/CRT-1154.trt\r: Cannot stat: No such file or directory

is the hint you have to catch: it's looking for a file that ends with .trt\r, not .trt.

You can convert your test.txt file to contain Linux-style LF newlines to fix the problem, or else filter the CR's as you read the file, as @vmicrobio says in a comment to another answer.

By the way, if you use Git Bash on Windows, you might notice that it can read files with CRLF and process them correctly. That's because a patch was applied just to Git Bash to allow that very common situation. But on Linux, it's treating that CR as part of the command.

CodePudding user response：

A while loop and BASH parameter expansion should be all that you need:

while read -r p ; do crt="${p##*/}"; echo kubectl cp ns-mv/gen-0:$p /tmp/$crt ; echo "/tmp/$crt" ; done <test.txt
kubectl cp ns-mv/gen-0:/opt/gen/AughGEN/OutCSY/CRT-1154.trt /tmp/CRT-1154.trt
/tmp/CRT-1154.trt

Remove the echo from echo ubectl cp ns-mv/gen-0:$p /tmp/$crt to execute the kubectl commands:

while read -r p ; do crt="${p##*/}"; kubectl cp ns-mv/gen-0:$p /tmp/$crt ; echo "/tmp/$crt" ; done <test.txt

Further, as a first step in debugging, you can add a suitable shebang to your code and paste your code into shellcheck.net and implement any recommended changes.

CodePudding user response：

The command is not recognizing the space, you may use double quotes instead of single quotes to enclose the awk command, such as:

while read p; do
    echo "$p"
    CRT=$(echo -n "$p" | awk -F '/' '{print $6}')
    echo -n "$CRT"
    kubectl cp ns-mv/gen-0:$p /tmp/$CRT
done < test.txt