lsof not giving o/p for bash built in read

Question

When I do

find /

on a terminal and then do on another terminal

lsof -a -d 0-2 -c fin

I see o/p listed from execution of lsof command.

But when I do

echo hi ; read -t 30 hello
hi

on the same terminal ( as find) and do (on different terminal)

lsof -a -d 0-2 -c read

I don't get any output from lsof command

Why ? Is it because read is bash built in ? Whats happening here ?

This question technically belongs on [unix and linux](http://unix.stackexchange.com/) — Mike Pennington, Jun 18 '11 at 20:35

Pawel Veselov · Accepted Answer · 2011-06-18T22:52:00.497

3

You got it right. "read" is a shell built-in. The process name remains sh (or bash, or zsh, or whatever else is your shell of choice).

Moreover, though for some shell built-ins there are binary alternatives, there isn't one for read. Really because of its syntax, it takes in the name of a shell variable that gets assigned the result of reading from the stdin. If it was an external program, it could never set the variable in the calling shell.

edited Jun 18 '11 at 22:52

answered Jun 18 '11 at 20:41

Pawel Veselov

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from bash's 'help read': If no NAMEs are supplied, the line read is stored in the REPLY variable. – Pawel Veselov Jun 18 '11 at 21:00

lsof not giving o/p for bash built in read

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