Shell – How to extract the file size with du

disk-usageshelltext processing

I'm using du to get the file size of the result archive in a packager script:

> du -smh archive.zip
51M    archive.zip

I'd like to assign just the 51M part to a variable, to be able to print:

Archive size: 51M

How can I do that?

Best Answer

You can do it like so:

$ variable=$(du -smh archive.zip | awk '{print $1}')

Details

awk will parse the output breaking it up into columns. You want just the results from column #1. The $( .. ) code will run a command and return its results.

Related Solutions

Bash Scripting – How to Get the Size of a File

Your best bet if on a GNU system:

stat --printf="%s" file.any

From man stat:

%s total size, in bytes

In a bash script :

#!/bin/bash
FILENAME=/home/heiko/dummy/packages.txt
FILESIZE=$(stat -c%s "$FILENAME")
echo "Size of $FILENAME = $FILESIZE bytes."

NOTE: see @chbrown's answer for how to use stat in terminal on Mac OS X.

DD Command Output – How to Send to awk/sed/grep

The problem is your designated output from dd goes to STDERR and not STDOUT so you have to redirect STDERR as well and not only STDOUT.

For bash and zsh you can use |& instead of | which will also redirect STDERR to STDIN of the second command, e.g:

dd if=/dev/urandom of=/dev/null bs=1K count=10000 |& awk '/copied/ {print $8 " "  $9}'

The more general approach is to redirect STDERR explicitly with 2>&1, e.g:

dd if=/dev/urandom of=/dev/null bs=1K count=10000 2>&1 | awk '/copied/ {print $8 " "  $9}'

For the python part have a look at at the subprocess module and Popen in particular.

Best Answer

Details

Related Solutions

Bash Scripting – How to Get the Size of a File

DD Command Output – How to Send to awk/sed/grep

Related Question