Find the line number where an echo appear in a bash script

Question

It is possible to make the following bash script to work as I said in the title?

#!/bin/bash echo_report() { echo "echo on line $1" } trap 'echo_report $LINENO' [sigspec] #same code here echo "hi" #more code here

I don't know what should I use for [sigspec]...

If using trap is not possible, what other options do I have?

Trap doesn't work that way. It reacts on signals emitted by the OS or an external program. You can, however, do something like kill -SIGUSR1 $$ and your trap would be trap 'echo_report $LINENO' SIGUSR1 — thom
– thom, Commented Nov 7, 2013 at 15:19
You can use the DEBUG signal, but that is non-selective; it is triggered by (just about) every command, not just, say, echo commands. — chepner
– chepner, Commented Nov 7, 2013 at 15:30

Aron Griffis · Accepted Answer · 2013-11-07 15:21:17Z

6

Wrap echo in a function, then use caller to display the line number:

#!/bin/bash echo() { caller command echo "$@" } echo "hi"

Result:

$ bash foo.bash 8 foo.bash hi

answered Nov 7, 2013 at 15:21

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2 Comments

Why command echo and not builtin echo or even use printf? Do you really like the external command echo?

command doesn't force external. It just ignores functions. See gnu.org/software/bash/manual/bashref.html#Bash-Builtins