BASH - never execute unless environment variable is defined and certain value
58433
What's a concise way to check that environment variables are set in a Unix shell script?
53110
Is there a way to write a Bash function which aborts the whole execution, no matter how it is called?
139705
Setting or modifying a (system wide) environment variable in cmd.exe
82577
How to stop a script from running if it's not root (and echo "Not running as root! Exiting...")
92426
Execute a script when the output of a command has a specific string
147454
Why does bash set $? (exit status) to non-zero on Ctrl-C or Ctrl-Z?
56072
How do I compare two string variables in an 'if' statement in Bash?
29812
How do I test if a variable is a number in Bash?
37703
How can I check if a directory exists in a Bash shell script?
254
Setting environment variables on OS X
70899
BASH script to set environment variables not working
152015
Can a script modify an environment variable of its calling shell?
6958
How can I check if a program exists from a Bash script?
158457
Using | pipe character from a $variable makes it treat as just another argument in bash; how to escape it?
60776
What's the best distro/shell-agnostic way to set environment variables?
57604
Set variable conditionally on command line
85255
Detecting failure of a Bash "export" value