Ruby sprintf from the command line.

.gitignore

/ronn

README.md

sprintf(1) -- reformat text a-la sprintf

SYNOPSIS

sprintf [options] FILES...

DESCRIPTION

Print files using the specified sprintf format. Reads from stdin if no files are specified. Use '-' as a file to specify stdin manually. By default the input is not changed (equivalent to -c).

OPTIONS

These options control how sprintf operates:

• -b: binary output

• -c: string output

• -d: debug mode

• -f FORMAT: custom format

• -h, --help: print this help

• -o: octal output

• -x: hex output

INSTALLATION

Add sprintf to your PATH (or execute it directly). A nice way of doing so is to clone the repo and add the bin dir to PATH. This allows easy updates via git pull and should make the manpages available via man sprintf.

git clone git://gist.github.com/2638925.git
export PATH="$PATH:$(pwd)/2638925/bin"

abc.txt

abc

links

# Code
http://bit.ly/rmr12-sprintf

# Testing shell scripts
github/thinkerbot/ts

Simon Chiang
@thinkerbot

sprintf

#!/usr/bin/env ruby
begin
require 'optparse'

format = "%c"
OptionParser.new do |opts|
  opts.banner = %{
Usage: sprintf [options] FILES...

  Print files using the specified sprintf format.  Reads from stdin if no files
  are specified.  Use '-' as a file to specify stdin manually.  By default the
  input is not changed (equivalent to -c).

Options:
}.lstrip

  opts.on("-b", "binary output") do
    format = "%b"
  end

  opts.on("-c", "string output") do
    format = "%c"
  end

  opts.on("-d", "debug mode") do
    $DEBUG = true
  end

  opts.on("-f FORMAT", "custom format") do |str|
    format = str
  end

  opts.on("-h", "--help", "print this help") do
    puts opts
    puts
    exit
  end

  opts.on("-o", "octal output") do
    format = "%o "
  end

  opts.on("-x", "hex output") do
    format = "%x "
  end
end.parse!

if ARGV.empty? 
  ARGV << '-' 
end

ARGV.each do |file|
  File.open(file == '-' ? 0 : file) do |io|
    while b = io.getbyte
      print format % b
    end
  end
end

rescue Interrupt
  exit 130

rescue Errno::EPIPE 
  exit 0

rescue
  raise if $DEBUG
  $stderr.puts $!.message
  exit 1
end

sprintf.1

.\" generated with Ronn/v0.7.3
.\" http://github.com/rtomayko/ronn/tree/0.7.3
.
.TH "SPRINTF" "1" "September 2012" "1.0.0" ""
.
.SH "NAME"
\fBsprintf\fR \- reformat text a\-la sprintf
.
.SH "SYNOPSIS"
\fBsprintf\fR \fIoptions\fR FILES\.\.\.
.
.SH "DESCRIPTION"
Print files using the specified sprintf format\. Reads from stdin if no files are specified\. Use \'\-\' as a file to specify stdin manually\. By default the input is not changed (equivalent to \-c)\.
.
.SH "OPTIONS"
These options control how \fBsprintf\fR operates:
.
.TP
\fB\-b\fR
binary output
.
.TP
\fB\-c\fR
string output
.
.TP
\fB\-d\fR
debug mode
.
.TP
\fB\-f FORMAT\fR
custom format
.
.TP
\fB\-h\fR,\fB\-\-help\fR
print this help
.
.TP
\fB\-o\fR
octal output
.
.TP
\fB\-x\fR
hex output
.
.SH "INSTALLATION"
Add \fBsprintf\fR to your PATH (or execute it directly)\. A nice way of doing so is to clone the repo and add the bin dir to PATH\. This allows easy updates via \fBgit pull\fR and should make the manpages available via \fBman sprintf\fR\.
.
.IP "" 4
.
.nf

git clone git://gist\.github\.com/2638925\.git
export PATH="$PATH:$(pwd)/2638925/bin"
.
.fi
.
.IP "" 0

sprintf_0.rb

# Step 0 - write it
#
#   ruby sprintf_0.rb
#
File.open("abc.txt") do |io|
  while b = io.getbyte
    print "%b" % b
  end
end

sprintf_1.rb

require 'optparse'

# Step 1 - write it with opts and args
#
#   ruby sprintf_1.rb -b abc.txt xyz.txt
#   ruby sprintf_1.rb abc.txt xyz.txt
#
format = "%c"
OptionParser.new do |opts|
  opts.banner = %{
Usage: #{$0} [options] FILES...

  Print files using the specified sprintf format.  Reads from stdin if no files
  are specified.  Use '-' as a file to specify stdin manually.  By default the
  input is not changed (equivalent to -c).

Options:
}.lstrip

  opts.on("-b", "binary output") do
    format = "%b"
  end

  opts.on("-c", "string output") do
    format = "%c"
  end

  opts.on("-d", "debug mode") do
    $DEBUG = true
  end

  opts.on("-f FORMAT", "custom format") do |str|
    format = str
  end

  opts.on("-h", "--help", "print this help") do
    puts opts
    puts
    exit
  end

  opts.on("-o", "octal output") do
    format = "%o "
  end

  opts.on("-x", "hex output") do
    format = "%x "
  end
end.parse!

ARGV.each do |file|
  File.open(file) do |io|
    while b = io.getbyte
      print format % b
    end
  end
end

sprintf_2

#!/usr/bin/env ruby
require 'optparse'

# Step 2 - hide the fact this is ruby
#
#   chmod +x ./sprintf_2
#   ./sprintf_2 abc.txt xyz.txt
#
format = "%c"
OptionParser.new do |opts|
  opts.banner = %{
Usage: #{$0} [options] FILES...

  Print files using the specified sprintf format.  Reads from stdin if no files
  are specified.  Use '-' as a file to specify stdin manually.  By default the
  input is not changed (equivalent to -c).

Options:
}.lstrip

  opts.on("-b", "binary output") do
    format = "%b"
  end

  opts.on("-c", "string output") do
    format = "%c"
  end

  opts.on("-d", "debug mode") do
    $DEBUG = true
  end

  opts.on("-f FORMAT", "custom format") do |str|
    format = str
  end

  opts.on("-h", "--help", "print this help") do
    puts opts
    puts
    exit
  end

  opts.on("-o", "octal output") do
    format = "%o "
  end

  opts.on("-x", "hex output") do
    format = "%x "
  end
end.parse!

ARGV.each do |file|
  File.open(file) do |io|
    while b = io.getbyte
      print format % b
    end
  end
end

sprintf_3

#!/usr/bin/env ruby
begin
require 'optparse'

format = "%c"
OptionParser.new do |opts|
  opts.banner = %{
Usage: #{$0} [options] FILES...

  Print files using the specified sprintf format.  Reads from stdin if no files
  are specified.  Use '-' as a file to specify stdin manually.  By default the
  input is not changed (equivalent to -c).

Options:
}.lstrip

  opts.on("-b", "binary output") do
    format = "%b"
  end

  opts.on("-c", "string output") do
    format = "%c"
  end

  opts.on("-d", "debug mode") do
    $DEBUG = true
  end

  opts.on("-f FORMAT", "custom format") do |str|
    format = str
  end

  opts.on("-h", "--help", "print this help") do
    puts opts
    puts
    exit
  end

  opts.on("-o", "octal output") do
    format = "%o "
  end

  opts.on("-x", "hex output") do
    format = "%x "
  end
end.parse!

ARGV.each do |file|
  File.open(file) do |io|
    while b = io.getbyte
      print format % b
    end
  end
end

# Step 3 - handle errors gracefully
#
#   ./sprintf_3 missing_file
#
rescue
  raise if $DEBUG
  $stderr.puts $!.message
  exit 1
end

sprintf_4

#!/usr/bin/env ruby
begin
require 'optparse'

format = "%c"
OptionParser.new do |opts|
  opts.banner = %{
Usage: #{$0} [options] FILES...

  Print files using the specified sprintf format.  Reads from stdin if no files
  are specified.  Use '-' as a file to specify stdin manually.  By default the
  input is not changed (equivalent to -c).

Options:
}.lstrip

  opts.on("-b", "binary output") do
    format = "%b"
  end

  opts.on("-c", "string output") do
    format = "%c"
  end

  opts.on("-d", "debug mode") do
    $DEBUG = true
  end

  opts.on("-f FORMAT", "custom format") do |str|
    format = str
  end

  opts.on("-h", "--help", "print this help") do
    puts opts
    puts
    exit
  end

  opts.on("-o", "octal output") do
    format = "%o "
  end

  opts.on("-x", "hex output") do
    format = "%x "
  end
end.parse!

# Step 4 - handle stdin as a file
#
#   cat abc.txt | ./sprintf_4 - xyz.txt
#
ARGV.each do |file|
  File.open(file == '-' ? 0 : file) do |io|
    while b = io.getbyte
      print format % b
    end
  end
end

rescue
  raise if $DEBUG
  $stderr.puts $!.message
  exit 1
end

sprintf_5

#!/usr/bin/env ruby
begin
require 'optparse'

format = "%c"
OptionParser.new do |opts|
  opts.banner = %{
Usage: #{$0} [options] FILES...

  Print files using the specified sprintf format.  Reads from stdin if no files
  are specified.  Use '-' as a file to specify stdin manually.  By default the
  input is not changed (equivalent to -c).

Options:
}.lstrip

  opts.on("-b", "binary output") do
    format = "%b"
  end

  opts.on("-c", "string output") do
    format = "%c"
  end

  opts.on("-d", "debug mode") do
    $DEBUG = true
  end

  opts.on("-f FORMAT", "custom format") do |str|
    format = str
  end

  opts.on("-h", "--help", "print this help") do
    puts opts
    puts
    exit
  end

  opts.on("-o", "octal output") do
    format = "%o "
  end

  opts.on("-x", "hex output") do
    format = "%x "
  end
end.parse!

# Step 5 - handle stdin by default
#
#   cat abc.txt xyz.txt | ./sprintf_5
#
if ARGV.empty? 
  ARGV << '-' 
end

ARGV.each do |file|
  File.open(file == '-' ? 0 : file) do |io|
    while b = io.getbyte
      print format % b
    end
  end
end

rescue
  raise if $DEBUG
  $stderr.puts $!.message
  exit 1
end

sprintf_6

#!/usr/bin/env ruby
begin
require 'optparse'

format = "%c"
OptionParser.new do |opts|
  opts.banner = %{
Usage: #{$0} [options] FILES...

  Print files using the specified sprintf format.  Reads from stdin if no files
  are specified.  Use '-' as a file to specify stdin manually.  By default the
  input is not changed (equivalent to -c).

Options:
}.lstrip

  opts.on("-b", "binary output") do
    format = "%b"
  end

  opts.on("-c", "string output") do
    format = "%c"
  end

  opts.on("-d", "debug mode") do
    $DEBUG = true
  end

  opts.on("-f FORMAT", "custom format") do |str|
    format = str
  end

  opts.on("-h", "--help", "print this help") do
    puts opts
    puts
    exit
  end

  opts.on("-o", "octal output") do
    format = "%o "
  end

  opts.on("-x", "hex output") do
    format = "%x "
  end
end.parse!

if ARGV.empty? 
  ARGV << '-' 
end

ARGV.each do |file|
  File.open(file == '-' ? 0 : file) do |io|
    while b = io.getbyte
      print format % b
    end
  end
end

# Step 6 - gracefully handle interrupt
#
#   yes | ./sprintf_6 > /dev/null # ctrl-c
#   echo $?                       # 130
#
# * [POSIX Spec](http://pubs.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html)
# * [Advanced BASH scripting guide](http://tldp.org/LDP/abs/html/exitcodes.html)
#
rescue Interrupt
  exit 130

rescue
  raise if $DEBUG
  $stderr.puts $!.message
  exit 1
end

sprintf_7

#!/usr/bin/env ruby
begin
require 'optparse'

format = "%c"
OptionParser.new do |opts|
  opts.banner = %{
Usage: #{$0} [options] FILES...

  Print files using the specified sprintf format.  Reads from stdin if no files
  are specified.  Use '-' as a file to specify stdin manually.  By default the
  input is not changed (equivalent to -c).

Options:
}.lstrip

  opts.on("-b", "binary output") do
    format = "%b"
  end

  opts.on("-c", "string output") do
    format = "%c"
  end

  opts.on("-d", "debug mode") do
    $DEBUG = true
  end

  opts.on("-f FORMAT", "custom format") do |str|
    format = str
  end

  opts.on("-h", "--help", "print this help") do
    puts opts
    puts
    exit
  end

  opts.on("-o", "octal output") do
    format = "%o "
  end

  opts.on("-x", "hex output") do
    format = "%x "
  end
end.parse!

if ARGV.empty? 
  ARGV << '-' 
end

ARGV.each do |file|
  File.open(file == '-' ? 0 : file) do |io|
    while b = io.getbyte
      print format % b
    end
  end
end

rescue Interrupt
  exit 130

# Step 7 - gracefully handle closed pipe:
#
#   yes | ./sprintf_7 | ruby -e '$stdin.close'
#   echo $? # 0
#
rescue Errno::EPIPE 
  exit 0

rescue
  raise if $DEBUG
  $stderr.puts $!.message
  exit 1
end

step_8

Step 8 - add to path

    cd ..
    which sprintf
    export PATH="$PATH:$(pwd)/bin"
    which sprintf
    sprintf -h

step_9

Step 9 - Add a man page

Use ronn:

    git clone git://github.com/rtomayko/ronn.git

Correction, use a fork of ronn:

    git clone git://github.com/thinkerbot/ronn.git
    mkdir -p man/man1
    ruby -Ironn/lib ronn/bin/ronn -r --pipe README.md > man/man1/sprintf.1

Optionally release info:

    ruby -Ironn/lib ronn/bin/ronn -r --pipe --organization="$(VERSION)" --date="$(DATE)" README.md > man/man1/sprintf.1

Now:

    man sprintf

xyz.txt

xyz