26 окт. 2012 г. · A safer way to check is to enclose both sides in double quotes, ie if [ "$depth" -eq "0" ] ; this way, an unset variable ( $depth ) evaluates to "". Bash `if $variable; then` returns `0: command not found` Bash: Why does [[ zero -eq 0 ]] evaluate to true? - Stack Overflow Bash - Check which variable is not equal to zero - Stack Overflow 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. bash script if variable equals - Unix & Linux Stack Exchange Bash variable ${0##*/} - Unix & Linux Stack Exchange Другие результаты с сайта unix.stackexchange.com

16 дек. 2013 г. · As David points out below, you must use "-eq" to test numeric values. You might also want to check for a blank variable to avoid errors; if [ !

3 дек. 2013 г. · Curiously, var=0; ((var++)) returns an error code while var=0; ((var++)); ((var++)) does not. Any idea why? – phunehehe. Commented Mar 26, 2014 ...

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.

15 дек. 2010 г. · A number is assigned to a variable and I wanted to check if it is a zero or non zero. Example of my numbers are below:

30 апр. 2009 г. · Here's a 100% fool-proof (and well-readable) line for you: [[ $1 =~ "^[0-9]+$" ]] && { echo "number"; exit 0; } || { echo "not a number"; exit 1; }

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

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.

1 июн. 2018 г. · Here's a quick explanation: gt - greater than; ge - greater or equal than; $( ... ) becomes the output of the command inside the parentheses.