26 окт. 2012 г. · This means that the expression [ $depth -eq $zero ] becomes [ -eq 0 ] after bash substitutes the values of the variables into the expression. How to check if $? is not equal to zero in unix shell scripting? Bash `if $variable; then` returns `0: command not found` Bash: Why does [[ zero -eq 0 ]] evaluate to true? - Stack Overflow Linux Bash, Test command, why [ 0 -ne 0 ] is false instead of true? Другие результаты с сайта stackoverflow.com

19 сент. 2022 г. · The common idiom for that is to check if the variable's value consists of nothing but numbers. With newer bash shells, you can use =~ and a regular expression. Check for non-empty string in the shell (instead of ! -z) bash - True if the length of string is (non)zero? [duplicate] Другие результаты с сайта unix.stackexchange.com

19 мар. 2022 г. · You can pass the -z option to the if command or conditional expression. If the length of STRING is zero, variable ($var) is empty.

13 мар. 2013 г. · It is a command that evaluates expressions. The [ 0 ] returns true because the form [ Expression ] always evaluates to 0.

11 февр. 2013 г. · Supposing your array is $errors , just check to see if the count of elements is zero. if [ ${#errors[@]} -eq 0 ]; then echo "No errors, ...

23 окт. 2021 г. · To check if a string is empty in a Bash script, use the -z conditional which returns 0 (true) if the length of the string is 0 and 1 (false) if it is greater ...

16 дек. 2013 г. · [ "$Server_Name" -eq 1 ] checks is the $Server_Name is equal to the number 1 , ie, it does a numeric comparison instead of a string comparison.

12 мая 2009 г. · You can test to see if a variable is specifically unset (as distinct from an empty string): if [[ -z ${variable+x} ]] where the "x" is arbitrary.

25 сент. 2023 г. · Thing #4. True means zero. In Bash True means a return status of zero, while False means a return status different from zero.

This tutorial aims to help the reader understanding conditions in bash, and provides a comprehensive list of the possibilities.