Re: fix scope problem with variable in bash script

On Wednesday 27 July 2022, kf wrote:

#!/bin/bash

#How to declare the variable "count"??? count=0

cat $1 | while read line do      count=$((count+1))      echo -n "$count " done

echo echo File $1 has $count lines.

As other have explained, the pipe receiver runs in it's own subprocess.   If you were in a situation where you did really have to read from a pipe, you could also code it as follows: #!/bin/bash cat $1 | {     count=0     while read line     do          count=$((count+1))          echo -n "$count "     done     echo     echo File $1 has $count lines. }