Bash For Loop Array: Iterate Through Array Values
#!/bin/bash
# declare an array called array and define 3 vales
array=( one two three )
for i in "${array[@]}"
do
echo "$i"
done
Running Bash commands in Python
To somewhat expand on the earlier answers here, there are a number of details which are commonly overlooked.
- Prefer
subprocess.run()oversubprocess.check_call()and friends oversubprocess.call()oversubprocess.Popen()overos.system()overos.popen() - Understand and probably use
text=True, akauniversal_newlines=True. - Understand the meaning of
shell=Trueorshell=Falseand how it changes quoting and the availability of shell conveniences. - Understand differences between
shand Bash - Understand how a subprocess is separate from its parent, and generally cannot change the parent.
- Avoid running the Python interpreter as a subprocess of Python.
Push-button installer of macOS Catalina, Mojave, and High Sierra guests in Virtualbox
macos-guest-virtualbox.sh is a Bash script that creates a macOS virtual machine guest on VirtualBox with unmodified macOS installation files downloaded directly from Apple servers.
A default install only requires the user to sit patiently and, less than ten times, press enter when prompted by the script, without interacting with the virtual machine.
Tested on bash and zsh on Cygwin. Works on macOS, CentOS 7, and Windows on x86 CPUs with VT-x or AMD-V. Should work on most modern Linux distros.
macOS Catalina (10.15), Mojave (10.14), and High Sierra (10.13) currently supported.
git – getting ALL previous version of a specific file/folder
The script would:
– extract all file versions to /tmp/all_versions_exported
– take 1 argument – relative path to the file inside git repo
– give result filenames numeric prefix (sortable)
– mention inspected filename in result files (to tell apples apart from oranges:)
– mention commit date in the result filename (see output example below)
– not create empty result files
Linux Bash Scripting Part3 – Parameters and Options
To pass data to your shell script, you should use command line parameters.
Options are single letters with a dash before it.
How to Make Simple Graphical Shell Scripts with Zenity on Linux
Zenity adds graphical interfaces to shell scripts with a single command.
Shell parameter expansion: bash native regular expresssion for replacements
The ‘$’ character introduces parameter expansion, command substitution, or arithmetic expansion. The parameter name or symbol to be expanded may be enclosed in braces, which are optional but serve to protect the variable to be expanded from characters immediately following it which could be interpreted as part of the name.
When braces are used, the matching ending brace is the first ‘}’ not escaped by a backslash or within a quoted string, and not within an embedded arithmetic expansion, command substitution, or parameter expansion.
Create User Accounts with Random Password with a bash script
#!/bin/bash #### # This script automatically creates user accounts with random passwords. # # Author: Russ Sanderlin # Date: 01/21/15 # ### if [ $# -lt 1 ]; then echo "Please supply a user name" echo "Example: " $0 "jsmith" exit fi # Declare local variables, generate random password. newuser=$1 randompw=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 8 | head -n 1) # Create new user and assign random password. useradd $newuser echo $newuser:$randompw | chpasswd echo "UserID:" $newuser "has been created with the following password:" $randompw