Re: fix scope problem with variable in bash script

27 Jul 2022


      On 7/26/22 5:56 PM, Michael Hamilton wrote:
...
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.
}
Nice.  Thanks.  It's always good to have options.