Linked Questions

At this question in the answer from Kyle Brandt the [[ ]] construct is described as a "bash built-in test command". The following is shown as an example. if [[ ( $a -gt 2 ) && ( $a -lt 5 )...

I have a problem with bash, I'm trying to detect strings in a file with bash with the file looking like cnlog "Hello World!" When i try the [ $variable = *" ] in bash it doesn't work ...

Assume a user fed time : read -p "Enter the start time you want to start(hh:mm:ss) " user_start_time and the regex : timePattern="[0-2][0-3]:[0-5][0-9]:[0-5][0-9]" if i do : if [ "$user_start_time"...

I was trying to use a bash script to validate some strings. No matter what I've tried, the script ends up matching every string provided as input and it's printing yes in the terminal. For example, ...

I am trying some simple input validation in bash. Basically this part of my script outputs "press [index] to select [array element]." However I cannot seem to get it to stop and exit ...

I have a simple for-loop that iterates over a glob-pattern and enters an if condition, for when the directory path is not equal to */venv then print the file. How can I get this working in the if ...

How do I iterate over a range of numbers in Bash when the range is given by a variable? I know I can do this (called "sequence expression" in the Bash documentation): for i in {1..5}; do ...

When writing shell programs, we often use /bin/sh and /bin/bash. I usually use bash, but I don't know what's the difference between them. What's the main difference between Bash and sh? What do we ...

I'm trying to learn shell scripting, and I need to understand someone else's code. What is the $? variable hold? I can't Google search the answer because they block punctuation characters.

What does echo $? mean in shell programming?

I've seen Bash scripts test for a non-zero length string in two different ways. Most scripts use the -n option: #!/bin/bash # With the -n option if [ -n "$var" ]; then # Do something when var is ...

My whole script is currently this: #!/bin/sh clear; blanko=""; # Dummy-Variablen variable=Testvariable; if [[$variable == $blanko]]; then echo "Nichts da!" else ...

In Bash, is there a simple way to test if one string is lexicographically less than or equal to another? I know you can do: if [[ "a" < "b" ]] for testing strict inequality, or if [[ 1 -le 1 ]] ...

I see here that testing whether $? is zero (success) or something else (failure) is an anti-pattern, but I have not been able to find this anywhere else. Sticking to the definition of anti-pattern of ...

So yes I am doing this for school but I have most of the script written. I don't know what's going on with it, maybe a syntax error but it keeps messing up(or I do). The first issue is that it keeps ...