• sf – script framework
• Usage
  • 1. sf-variables
    • sfargs
    • sfexamples
  • 2. Including sf
  • 3. Write your script
    • Output functions
    • Text formatting variables
• Example

sf – script framework

script framework can be used to simplify and beautify bash scripts. It provides:

• Argument parsing
• Usage output
• Output functions
• Text formatting variables

All just by declaring some variables and sourcing a file or adding an oneliner.

The usage is pretty self-explanatory once you have seen it. Head directly to the example to see it in action.

---

Here is the oneliner which was created with this tool:

  # sf -- script framework (https://github.com/Deleh/sf)
  sftrst=`echo -e "\e[0m"`;sftbf=`echo -e "\e[1m"`;sftdim=`echo -e "\e[2m"`;sftul=`echo -e "\e[4m"`;sftblink=`echo -e "\e[5m"`;sftinv=`echo -e "\e[7m"`;sfthide=`echo -e "\e[8m"`;sftk=`echo -e "\e[30m"`;sftr=`echo -e "\e[31m"`;sftg=`echo -e "\e[32m"`;sfty=`echo -e "\e[33m"`;sftb=`echo -e "\e[34m"`;sftm=`echo -e "\e[35m"`;sftc=`echo -e "\e[36m"`;sftw=`echo -e "\e[97m"`;function _sferr { echo -e "${sftbf}${sftr}SF PARSE ERROR${sftrst} $1";exit 1;};function sferr { echo -e "${sftbf}${sftr}ERROR${sftrst} $1";if [ -z "$2" ];then exit 1;fi;};function sfwarn { echo -e "${sftbf}${sfty}WARNING${sftrst} $1";};OLDIFS=$IFS;IFS=";";_sfphead="";_sfpdesc="";_sfodesc="";_sfexamples="";_sfpargs=();declare -A _sfflags;declare -A _sfargs;for a in "${sfargs[@]}";do subst=${a//";"};count="$(((${#a} - ${#subst})))";if [ $count -eq 1 ];then read -r -a _sfparsearr<<<"${a}";_sfpargs+=("${_sfparsearr[0]}");_sfphead="$_sfphead ${_sfparsearr[0]}";_sfpdesc="$_sfpdesc  ${_sfparsearr[0]};${_sfparsearr[1]}\n";elif [ $count -eq 2 ];then read -r -a _sfparsearr<<<"${a}";_sfflags["-${_sfparsearr[1]}"]="${_sfparsearr[0]}";_sfflags["--${_sfparsearr[0]}"]="${_sfparsearr[0]}";declare ${_sfparsearr[0]}=false;_sfodesc="$_sfodesc  -${_sfparsearr[1]}, --${_sfparsearr[0]};${_sfparsearr[2]}\n";elif [ $count -eq 4 ];then read -r -a _sfparsearr<<<"${a}";_sfargs["-${_sfparsearr[1]}"]="${_sfparsearr[0]}";_sfargs["--${_sfparsearr[0]}"]="${_sfparsearr[0]}";declare ${_sfparsearr[0]}="${_sfparsearr[3]}";_sfodesc="$_sfodesc  -${_sfparsearr[1]}, --${_sfparsearr[0]} ${_sfparsearr[2]};${_sfparsearr[4]} (default: ${_sfparsearr[3]})\n";else _sferr "Wrong argument declaration: $a";fi;done;for e in "${sfexamples[@]}";do subst=${e//";"};count="$(((${#e} - ${#subst})))";if [ $count -eq 1 ];then read -r -a _sfparsearr<<<"${e}";_sfexamples="$_sfexamples  ${_sfparsearr[0]};${_sfparsearr[1]}\n";else _sferr "Wrong example declaration: $e";fi;done;IFS=$OLDIFS;function sfusage { if [ -z ${sfname+x} ];then sfname=$(basename "$0");else echo -n "Usage: $sfname";fi;if [ "$_sfodesc" != "" ];then echo -n " OPTIONS";fi;echo -e "$_sfphead";if [ ! -z ${sfdesc+x} ];then echo -e "\n$sfdesc";fi;if [ "$_sfpdesc" != "" ];then echo -e "\nPOSITIONAL ARGUMENTS";echo -e "$_sfpdesc"|column -c 80 -s ";" -t -W 2;fi;if [ "$_sfodesc" != "" ];then echo -e "\nOPTIONS";echo -e "$_sfodesc"|column -c 80 -s ";" -t -W 2;fi;if [ "$_sfexamples" != "" ];then echo -e "\nEXAMPLES";echo -e "$_sfexamples"|column -c 80 -s ";" -t -W 2;fi;if [ ! -z ${sfextra+x} ];then echo -e "\n$sfextra";fi;exit 0;};for a in "$@";do if [ "$a" == "-h" ]||[ "$a" == "--help" ];then sfusage;fi;done;while(("$#"));do if [ ! -z ${_sfflags["$1"]} ];then declare ${_sfflags["$1"]}=true;elif [ ! -z ${_sfargs["$1"]} ];then if [ -n "$2" ]&&[ "${2:0:1}" != "-" ];then declare ${_sfargs["$1"]}="$2";shift;else sferr "Argument for '$1' missing";fi;else if [ "${1:0:1}" == "-" ];then sferr "Unsupported argument: $1";else if [ "${#_sfpargs[@]}" != 0 ];then declare ${_sfpargs[0]}="$1";_sfpargs=("${_sfpargs[@]:1}");else sferr "Too many positional arguments";fi;fi;fi;shift;done;if [ ${#_sfpargs[@]} != 0 ];then for p in "${_sfpargs[@]}";do sferr "Positional argument '$p' missing" 0;done;exit 1;fi

Usage

The general usage is:

1. Declare sf-variables at the top of your script
2. Include sf
3. Write your script

1. sf-variables

This is the list of variables which can be set before including sf. Every variable is optional.

sfname	Name of the script in usage output (default: filename)
sfdesc	Description of the script
sfargs	Array for declaration of arguments, positional arguments and flags. Look below for more information
sfexamples	Array for declaration of examples for the usage output. Look below for more information
sfextra	Additional usage output

A complete example which uses every variable can be found below.

sfargs

This is an array of strings. Every string defines an argument, a flag or an positional argument of the script. The type is defined by the amount of semicolons in the string.

Positional argument	<name>;<description>
Flag	<name>;<shorthand>;<description>
Argument	<name>;<shorthand>;<value_name>;<default_value>;<description>

The order of declaration defines the order in the usage output.

sfexamples

This is also an array of strings. Examples can be declared like this: <command>;<description>

2. Including sf

Grab the sf file from the repo and place it next to your script. Then source the file with

  source sh

Or just copy and paste the oneliner from above.

3. Write your script

sf deals with missing inputs and handles the parsing of arguments. This means that after sf was included you can be sure that all variables have assigned values. Flags are either false or true, arguments have the provided value or the default value and positional arguments have the provided value.

The values are stored in variables with the name $<name>. If you declared for example a flag like this:

  sfargs+=("verbose:v:Enable verbose output")

Then the variable $verbose exists with a value of either false or true.

Output functions

sf provides two output functions which can be used to throw warnings and errors.

sfwarn	Takes a string as input and prints a warning
sferr	Takes a string as input, prints an error and exits with result code 1. If an additional argument is passed (doesn't matter what), it will just throw an error and don't exit

Text formatting variables

The following text formatting variables can be used to modify the output:

sftrst	Reset formatting
sftbf	Bold
sftdim	Dim
sftul	Underline
sftblink	Blinking
sftinv	Invert foreground/background
sfthide	Hidden
sftk	Black
sftr	Red
sftg	Green
sfty	Yellow
sftb	Blue
sftm	Magenta
sftc	Cyan
sftw	White

The variables can be used directly in echo, no -e needed. To echo the word "framework" bold and red use the variables for example like this:

  echo "${sftbf}${sftr}framework${sftrst}"

Example

Here is an example script which uses sf:

  #!/usr/bin/env bash

  # ----------------
  # sf header
  # ----------------

  # Set sf-variables
  sfname="calc"
  sfdesc="A simple calculator which can add and subtract."

  sfargs+=("A;First number")
  sfargs+=("B;Second number")
  sfargs+=("substract;s;Substract B from A")
  sfargs+=("multiply;m;MULTIPLICATOR;1;Multiply the result with MULTIPLICATOR")

  sfexamples+=("calc 3 5;Prints the result of 3 + 5")
  sfexamples+=("calc -s 2 1;Prints the result of 2 - 1")
  sfexamples+=("calc -m 3 -s 2 1;Prints the result of (2 - 1) * 3")

  sfextra="No copyright at all."

  # Source sf
  source sf

  # ----------------
  # Actual script
  # ----------------
  
  res=0
  if [ "$substract" == true ]; then
      res=`expr $A - $B`
  else
      res=`expr $A + $B`
  fi

  if [ "$multiply" -ge 1 ]; then
      res=`expr $res \* $multiply`
  fi

  echo "The result is $sftbf$res$sftrst."

The usage output of the above script:

  Usage: calc OPTIONS A B

  A simple calculator which can add and subtract.

  POSITIONAL ARGUMENTS
    A  First number
    B  Second number

  OPTIONS
    -s, --substract               Substract B from A
    -m, --multiply MULTIPLICATOR  Multiply the result with MULTIPLICATOR (default:
                                   1)

  EXAMPLES
    calc 3 5          Prints the result of 3 + 5
    calc -s 2 1       Prints the result of 2 - 1
    calc -m 3 -s 2 1  Prints the result of (2 - 1) * 3

  No copyright at all.