function::system - Linux
Overview
function::system
is a command-line tool used to execute system commands from within Bash functions. It provides a convenient way to run external commands as part of a function, enabling more complex and automated workflows.
Syntax
function::system [-h] [-v] [-e] [-i] [-s] [-f] [-p] [-l] [-c COMMAND]
Options/Flags
-h
,--help
: Display help message and exit.-v
,--verbose
: Enable verbose output, showing the executed command and its results.-e
,--exit-on-error
: Exit the function immediately if the executed command returns an error.-i
,--interactive
: Enable interactive mode, prompting the user for input before executing the command.-s
,--silent
: Suppress all output from the executed command.-f
,--filter-output
: Filter the output of the executed command using the specified regular expression.-p
,--pipe-output
: Pipe the output of the executed command to the standard output.-l
,--log-output
: Log the output of the executed command to the specified file.-c COMMAND
,--command COMMAND
: Specify the command to be executed.
Examples
Simple usage: Execute a system command and print its output:
function::system "echo Hello World!"
Verbose output: Enable verbose mode to see the executed command:
function::system -v "ls -l"
Exit on error: If the command fails, exit the function immediately:
function::system -e "rm -rf /"
Interactive mode: Prompt the user for input before executing the command:
function::system -i "read -p 'Enter a value: ' value; echo $value"
Filter output: Filter the output of the command using a regular expression:
function::system -f "grep error" "dmesg"
Pipe output: Pipe the output of the command to another command:
function::system -p "ls -l" | less -R
Log output: Log the output of the command to a file:
function::system -l /tmp/command-output.log "ls -l"
Common Issues
- Permission denied: Ensure that the current user has sufficient permissions to execute the specified command.
- Syntax error: Check the command syntax carefully for any typos or incorrect usage.
- Path not found: Verify that the specified command is available in the system’s PATH environment variable.
Integration
function::system
can be combined with other commands or tools to create complex workflows. For instance, it can be used within Bash scripts to conditionally execute commands:
if [[ $(function::system "ls -l /path/to/file") ]]; then
echo "File exists."
fi
Related Commands
sh
: Run a shell command.bash
: Run a Bash script.command
: Execute a single command.