/bin/sh shell set
August 11, 2016
The Bourne shell (sh) is a shell, or command-line interpreter, for computer operating systems.
The Bourne shell was the default shell for Unix Version 7. Most Unix-like systems continue to have /bin/sh—which will be the Bourne shell, or a symbolic link or hard link to a compatible shell even when other shells are used by most users. https://en.wikipedia.org/wiki/Bourne_shell
🔗set options
In sh, the set built-in command has the following options:
| option | Description |
|---|---|
| -- | An option of a double-dash ("--") signifies the end of an option list. This is primarily useful when values listed after the options will start with a dash themselves. |
| -a | Mark variables which are modified or created for "export"; environment variables set in this way will be passed on to the environments of any subsequent commands. |
| -e | Exit immediately if a command exits with a non-zero exit status. |
| -f | Disable file name generation (globbing). |
| -h | Locate and remember function commands as functions are defined (function commands are normally located when the function is executed). |
| -n | Read commands but do not execute them. |
| -t | Exit after reading and executing one command. |
| -u | Treat unset variables as an error when substituting. |
| -v | Print shell input lines as they are read. |
| -x | Print commands and their arguments as they are executed. |
Using + rather than - causes these flags to be turned off.
Example:
#!/bin/sh
set -e
set -x
test 1 -eq 0
echo "never printed"