robin-a-meade

Unofficial Bash Strict Mode

Sometimes a programming language has a "strict mode" to restrict unsafe constructs. E.g., Perl has use strict, Javascript has "use strict", and Visual Basic has Option Strict. But what about bash? Well, bash doesn't have a strict mode as such, but it does have an unofficial strict mode:

set -euo pipefail

set -e

tdryer

How Linux approximates memory metrics

Example

The program threads-memory.c (included below) starts 100 threads, allocates 1 MB of memory in each, and then pauses. How much memory is it using?

Let's find out by running it:

$ gcc -pthread threads-memory.c -o threads-memory

obscurerichard

slow

This bash script offers quick shortcuts to simulate slower network connections. It is useful when you need to simulate a wireless network on a Linux network server, especially when you are using a virtual machine guest on your local machine or in the cloud.

slow 3G                   # Slow network on default eth0 down to 3G wireless speeds
slow reset                # Reset connection for default eth0 to normal
slow vsat --latency=500ms # Simulate satellite internet  with a high latency
slow dsl -b 1mbps         # Simulate DSL with a slower speed than the default

slow modem-56k -d eth0 # Simulate a 56k modem on the eth1 device. eth0 is unchanged.