[SOLVED] Inline unix command as filename

Issue

I have the following bash script test.sh (with execution permissions):

#!/bin/sh
CAT_BIN="cat"
"$CAT_BIN"  <(tail -n +2 test.sh)

It gives me that error when I run it:

$ ./test.sh 
./test.sh: line 4: syntax error near unexpected token `('
./test.sh: line 4: `"$CAT_BIN"  <(tail -n +2 test.sh)'

However, when I source the following commands it executes alright.

$ CAT_BIN="cat"
$ "$CAT_BIN"  <(tail -n +2 test.sh)

How can this work in a script? (Use <(tail -n +2 test.sh) inline as a filename argument)

Solution

The <(tail -n +2 test.sh) construct is a bash feature, so you need to run your script in the bash shell,

Replace your top line

#!/bin/sh

with

#!/bin/bash

(Or the proper path to the bash executable if it is not /bin/bash on your system)

Note, even if /bin/sh is e.g. a symlink to bash, it will start bash in posix compatibility mode when you run it as /bin/sh , and many bash specific features will not be available)

Answered By - nos