#223 One-liners
All about one-liners with ruby.
Notes
The Ruby one-liners cookbook has it all!
Command Line Options
Using a ruby one-liner to format the ruby command line options as markdown for the table below…
ruby -h | ruby -F' ' -ane 'puts $F[0].include?("Usage") ? "| Option | Description |\n|---|---|\n" : "| `#{$F[1]}` | #{$_.chomp.gsub($F[1],"").strip} |"'
| Option | Description |
|---|---|
-0[octal] |
specify record separator (\0, if no argument) |
-a |
autosplit mode with -n or -p (splits $_ into $F) |
-c |
check syntax only |
-Cdirectory |
cd to directory before executing your script |
-d |
set debugging flags (set $DEBUG to true) |
-e 'command' |
one line of script. Several -e’s allowed. Omit [programfile] |
-Eex[:in] |
specify the default external and internal character encodings |
-Fpattern |
split() pattern for autosplit (-a) |
-i[extension] |
edit ARGV files in place (make backup if extension supplied) |
-Idirectory |
specify $LOAD_PATH directory (may be used more than once) |
-l |
enable line ending processing |
-n |
assume ‘while gets(); … end’ loop around your script |
-p |
assume loop like -n but print line also like sed |
-rlibrary |
require the library before executing your script |
-s |
enable some switch parsing for switches after script name |
-S |
look for the script using PATH environment variable |
-v |
print the version number, then turn on verbose mode |
-w |
turn warnings on for your script |
-W[level=2|:category] |
set warning level; 0=silence, 1=medium, 2=verbose |
-x[directory] |
strip off text before #!ruby line and perhaps cd to directory |
--jit |
enable JIT with default options (experimental) |
--jit-[option] |
enable JIT with an option (experimental) |
-h |
show this message, -elp for more info |
Examples
See the Ruby one-liners GitHub source for a full suite of examples.
$ ./examples.sh
Regexp based filtering - should match /foo/a/
/foo/a/report.log
Credits and References
- Ruby one-liners cookbook
- Ruby one-liners cookbook - GitHub sources