Check if the command exists in bash
2320
Why not use "which"? What to use then?
103354
How do I test if an item is in a bash array?
43775
Checking the success of a command in a bash `if [ .. ]` statement
152213
How can I search the bash history and rerun a command?
27233
Nested If Exist statements in Batch File
102365
Using the result of a command as an argument in bash?
40229
How do I check if a variable exists?
19329
How to check if directory exists in %PATH%?
67636
How to check the extension of a filename in a bash script?
29812
How do I test if a variable is a number in Bash?
23208
How can I check if a file exists in Perl?
111721
How to check if gcc has failed, returned a warning, or succeeded in Bash?
85968
How do I find a command if I don't know its name?
91447
Check if a method exists
86165
UNIX commands - find
70866
Check command success in bash
17361
How to check if a string has spaces in Bash shell