27 авг. 2012 г. · You can test for a non-empty string in Bash like this: if [[ $(ls -A) ]]; then echo "there are files" else echo "no files found" fi If output of bash command is empty, do something bash - give default string as output if command output is empty Другие результаты с сайта stackoverflow.com

5 июл. 2021 г. · The answer to the question in the title, to "check if output is non-empty, and print it if it is", is to just print it unconditionally. Check for non-empty string in the shell (instead of ! -z) How to check if a pipe is empty and run a command on the data ... 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.

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.

Check if the length of the output is non empty ( -n ). output=$(radon cc . -nc) if [[ -n "$output" ]]; then echo 'there is output' else echo 'no output' fi ...

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) ...

11 февр. 2013 г. · Try array=('' foo); [ -z "$array" ] && echo empty , and it will print empty even though array is clearly not empty.

27 июн. 2018 г. · Since you mentioned awk , here's one way. Note this is for empty output, i.e., print the default if myCommand outputs nothing at all.

Оценка 5,0 (7) 29 июл. 2021 г. · On the other hand, if the string is empty, it won't return true. n operator to check if string is not empty. -z operator. -z is the second ...

31 окт. 2011 г. · No need for counting anything or shell globs. You can also use read in combination with find . If find 's output is empty, you'll return false :