Run a binary with arguments using absolute path

Question

This is a embedded Linux system so things are a little different. I am trying to run an binary with arguments using absolute path but it doesn't work. If I run the binary from the folder it works e.g. if the binary is in /home/root/test folder and I run

root@user:~/test# ./mybinary 1 2 

it works with no issue. But below will not work, seems it is not able to understand the arguments

root@user:~# /home/root/test/mybinary 1 2 

In the end I want to run this binary using crontab where I would use the absolute path to call it.

Answer 1

If your program needs to be started from a certain directory, maybe because it is reading some files from there with relative paths, just change the directory first:

cd /home/root/test && mybinary 1 2 

(where mybinary is looked up in $PATH), or:

cd /home/root/test && ./mybinary 1 2 

To run the mybinary executable in that directory, or another relative or absolute path to that file such as /home/root/test/mybinary.

You may add another cd to change back after finishing:

if cd /home/root/test; then ./mybinary 1 2; cd -; fi 

The latter is superfluous if running from crontab. A better general approach to have only one (or a set of) command run in a separate directory is to use a subshell:

(cd /home/root/test && ./mybinary 1 2) 

The GNU, NetBSD and FreeBSD implementations of env (but not those of toybox or busybox as more commonly found on embedded systems) also have a -C option to change the working directory the command is run in:

env -C /home/root/test ./mybinary 1 2 

Creating a separate script for this purpose seems over-engineering.

Don't forget a comment in the crontab. If you are the author of said program, you should read from fixed config file like ~/.mybinaryrc or ~/.mybinary.conf or the like, or provide a directory switch, where to look for the files, so you can call it like that:

 mybinary --startdir ~/home/root/test 1 2