[How To] Redirect Text to a File Using sudo

In Ubuntu Linux (and a number of other systems) it is customary to use sudo to obtain root privileges, and often there is the task of writing (for example, via echo) any value to a file owned by the root user.

Many do it intuitively and incorrectly:

sudo echo Value > /path

This example does not work for the reason that using sudo you get root privileges, but the redirection to bsh (“>”) already works from your regular account.

Correctly, you can do this:

echo Value | sudo tee /path

Here is example that changes the processor’s operation scheme to “conservative” and sets starting frequency to 1.15 GHz:

echo conservative | sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo 1150000 | sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq

Test Environment

Ubuntu 19.10 (Eoan Ermine)

VMware Workstation 15.1.0



Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.