shell
Small simplistic helper class for executing shell commands in Crystal:
- run command,
- exit if it fails,
- return STDOUT of the command;
- optionally
- allow to ignore failure
- return STDERR of failed command.
Installation
Add this to your application's shard.yml
:
dependencies:
shell:
github: maiha/shell.cr
version: 0.4.2
Usage
require "shell"
Output of the shell command is available through #stdout
and #stderr
methods, numeric value of the exit status returned by the function #run
.
Simplest usage of the #run
method:
puts Shell.run("ls").stdout
If command fails Shell
raises exception, but this behaviour can be
overridden by fail_on_error
variable:
puts Shell.run("command_with_non_zero_status", fail_on_error: false).stderr
Shell::Seq
Shell::Seq
accumulates shell commands and those results.
When an error occur, '#run' doesn't raise any errors and just skips latter commands.
This is similar to Try monad concatinations.
shell = Shell::Seq.new
shell.run("mkdir /tmp/shell") if !Dir.exists?("/tmp/shell")
shell.run("git clone https://github.com/maiha/shell.cr.git", chdir: "/tmp/shell")
shell.run("ls /xxxxx")
shell.run("date")
shell.success? # => false
shell.last.stderr # => "ls: cannot access '/xxxxx': No such file or directory\n"
shell.map(&.cmd.split[0]) # => ["mkdir", "git", "ls"]
shell.log # shows `cmd`, `stdout`, `stderr` of all executed commands
# % mkdir /tmp/shell
# % git clone https://github.com/maiha/shell.cr.git
# Cloning into 'shell.cr'...
# % ls /xxxxx
# ls: cannot access '/xxxxx': No such file or directory
See test for further usage: spec/seq_spec.cr
Contributing
- Fork it ( https://github.com/dmytro/shell/fork )
- Create your feature branch (git checkout -b my-new-feature)
- Commit your changes (git commit -am 'Add some feature')
- Push to the branch (git push origin my-new-feature)
- Create a new Pull Request
Contributors
- dmytro Dmytro Kovalov - creator, maintainer