Check for non-empty string in the shell (instead of ! -z)
53269
bash - True if the length of string is (non)zero?
70881
Make bash exit != 0 when called by AWK and interrupted with ^C
147454
Why does bash set $? (exit status) to non-zero on Ctrl-C or Ctrl-Z?
85255
Detecting failure of a Bash "export" value
81489
How to use a special character as a normal one in Unix shells?
157168
How do I use a file grep comparison inside a bash if/else statement?
69530
Equivalent of (foo &>/dev/null &) in Windows shell
19908
How can I compare numbers in Bash?
124479
Check if a String contains a special character
12822
GNU find and masking the {} for some shells - which?
29812
How do I test if a variable is a number in Bash?
65304
How can I have a newline in a string in sh?
57228
Check for whitespace at beginning of string
63349
How to string-compare for a single space
69991
How do I use grep to search for the string "-1"
5085
Conditional trailing space with bash programmable completion
89873
PHP: a short cut for isset and !empty?