Limits of length for the expansion of * in Bash?

Question

In Bash

echo *

is almost equivalent to ls.

You can do things like

echo */*-out/*.html > all-my-html-files-on-one-line

Since * is a command line argument then there should be a limit on the length.

What is that limit?

Is the limit different between echo the Bash command and /bin/echo the program?

score 9 · Accepted Answer · edited Sep 26 '18 at 20:18

9

The shell does not limit this

You can see the limit for your system with (run on my 64bit linux:)

$ getconf ARG_MAX
2097152

edited Sep 26 '18 at 20:18

codeforester

answered Jun 23 '11 at 22:22

sehe

score 3 · Answer 2 · answered Jun 23 '11 at 22:21

3

I believe the command line limit is the value of ARG_MAX which you can see with

getconf ARG_MAX

This is not a bash variable, which would suggest that the limit is the same for echo in bash and /bin/echo.

answered Jun 23 '11 at 22:21

borrible

7

`echo` doesn't execute any external commands, so it's not affected by ARG_MAX. Try it out `/bin/echo $(seq $(getconf ARG_MAX))` will fail but `echo $(seq $(getconf ARG_MAX))` will probably succeed. – Piotr Praszmo Jun 23 '11 at 22:35

2 Answers2