仅当非交互式运行bash脚本时，出现错误“猫：写入错误：管道损坏”

Question

I wrote a bash script where I define a variable like this:

var=$(cat $file_path | head -n $var2 | tail -n 1 | cut -f1)

Where $file_path simply contains the path to a file and $var2 is an int, eg, 1 or 2. The variable is therefore assigned the value of the first field of line number var2 of the file.

It works perfectly fine when I run this from the command line. However, when running the script containing this command, I get the error

cat: write error: Broken pipe

Any idea why that is?

Answer 1

There's no need to use cat , since head takes a filename argument.

var=$(head -n $var2 $file_path | tail -n 1 | cut -f1)

Actually, there's no need to use any of those commands.

var=$(awk -v line=$var2 'NR == line { print $1; exit }' $file_path)