rswatch

A program for monitoring files and directories and executing command on change

Use cases

• Print modified, added, or removed files from directory structure
• Execute command for changed files

Examples

rswatch src -e cat {} Checks for changes in src directory and run cat with the changed files

rswatch src -p Print changed files to stdout

rswatch src -ke compile_and_run.sh Run compile_and_run.sh on any change to src directory. If the process is still running, e.g; program is in a loop, kill instead of wait (-k --kill flag)

This is useful if you're making an interactive application that runs in a loop or waits for used input. -k flag will kill the process and restart it rather than waiting for it to complete.

Setting up this script in a terminal can be used to automatically rebuild and run tests on save

Exiting

Using Ctrl-C (SIGINT) in terminal will terminate child process if running, if child process isn't running, it will prompt to confirm exit, simply enter y or enter to exit

This is to prevent accidental exit from rswatch when terminating child process

Usage

Accessible with rswatch --help

-, --(unnamed) [required]
    Specify which files and/or directories to watch

-h, --help 
    Show usage

-p, --print 
    Print modified files and directories to stdout

-v, --verbose 
    Verbose output

-i, --interval 
    Time in milliseconds between checks (default 100)

-k, --kill 
    Specifies to kill the child process `exec` rather than wait for it

-c, --clear 
    Clears the screen before restarting childprocess `exec`

-s, --start 
    Start the process `exec` on startup instead of waiting for a file to change before doing so

-e, --exec 
    Command to execute when files change
    All following arguments are given to the specified command
    {} is to be replaced by the changed files, to run command for each changed file separately
    Watch is not blocked during execution when process is spawned but will wait until previous finished before rerunning next check
    To kill and restart process rather than waiting, use option --kill