Running a command through /usr/bin/env has the benefit of looking for whatever the default version of the program is in your current environment. This way, you don’t have to look for it in a specific place on the system, as those paths may be in different locations on different systems. As long as it’s in your path, it … Read more
[ -z “${DEPLOY_ENV}” ] checks whether DEPLOY_ENV has length equal to zero. So you could run:
Is there a TRY CATCH command in Bash? No. Bash doesn’t have as many luxuries as one can find in many programming languages. There is no try/catch in bash; however, one can achieve similar behavior using && or ||. Using ||: if command1 fails then command2 runs as follows Similarly, using &&, command2 will run if command1 is successful The closest approximation of try/catch is as follows Also bash contains some error … Read more
$? is used to find the return value of the last executed command. Try the following in the shell: If somefile exists (regardless whether it is a file or directory), you will get the return value thrown by the ls command, which should be 0 (default “success” return value). If it doesn’t exist, you should get a number other then 0. The … Read more
To fix, open your script with vi or vim and enter in vi command mode (key Esc), then type this: Finally save it :x! or :wq!
This happens because you may have done a sudo su user_name and then fired the screen command. There are 2 ways to fix this. Login directly to “user_name” via ssh. Take ownership of the shell by typing script /dev/null as the user user_name and then type screen
This is the exit status of the last executed command. For example the command true always returns a status of 0 and false always returns a status of 1: From the manual: (acessible by calling man bash in your shell) $? Expands to the exit status of the most recently executed foreground pipeline. By convention an exit status of 0 means success, and non-zero return status … Read more
Use subprocess.Popen: Note that communicate blocks until the process terminates. You could use process.stdout.readline() if you need the output before it terminates. For more information see the documentation.
In addition to backticks `command`, command substitution can be done with $(command) or “$(command)”, which I find easier to read, and allows for nesting. Quoting (“) does matter to preserve multi-line variable values; it is optional on the right-hand side of an assignment, as word splitting is not performed, so OUTPUT=$(ls -1) would work fine.
I figured it out now. When you need to run two commands in exec in a find you need to actually have two separate execs. This finally worked for me.