sf/README.org
2022-01-15 09:58:27 +01:00

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* sf -- script framework
#+begin_center
#+caption: Logo
[[./images/logo.png]]
#+end_center
/script framework/ can be used to simplify and beautify bash scripts.
It provides:
- Argument parsing
- Usage output
- Input functions
- Output functions
- Text formatting variables
All just by declaring some variables and sourcing it.
Or keep your scripts self-contained and include it as an oneliner.
The usage is pretty self-explanatory once you have seen it.
If you're curious and don't want to read through the documentation, head directly to the [[#examples][examples]].
-----
Here is the oneliner version of /sf/ which was created with [[https://github.com/precious/bash_minifier][this]] tool:
#+begin_src sh
# sf -- script framework (https://github.com/Deleh/sf)
sftrs=$'\e[0m';sftbf=$'\e[1m';sftdim=$'\e[2m';sftul=$'\e[4m';sftblk=$'\e[5m';sftinv=$'\e[7m';sfthd=$'\e[8m';sftclr=$'\e[1A\e[K';sftk=$'\e[30m';sftr=$'\e[31m';sftg=$'\e[32m';sfty=$'\e[33m';sftb=$'\e[34m';sftm=$'\e[35m';sftc=$'\e[36m';sftw=$'\e[97m';function sferr { echo "${sftbf}${sftr}ERROR${sftrs} $1";[ -z "$2" ]&&exit 1;};function sfwarn { echo "${sftbf}${sfty}WARNING${sftrs} $1";};function sfask { if [ "$2" == "" ];then read -p "$1? [${sftbf}Y${sftrs}/${sftbf}n${sftrs}] " sfin;[[ "$sfin" =~ y|Y|^$ ]]&&sfin=true||sfin=false;else read -p "$1? [${sftbf}y${sftrs}/${sftbf}N${sftrs}] " sfin;[[ "$sfin" =~ n|N|^$ ]]&&sfin=false||sfin=true;fi;};function sfget { [ "$2" != "" ]&&read -p "$1 [${sftbf}$2${sftrs}]: " sfin||read -p "$1: " sfin;[ "$sfin" == "" ]&&[ "$2" != "" ]&&sfin="$2";};function _sferr { echo "${sftbf}${sftr}SF PARSE ERROR${sftrs} $1";exit 1;};OLDIFS=$IFS;IFS=";";_sfphead="";_sfpdesc="";_sfodesc="";_sfexamples="";_sfpargs=();declare -A _sfflags;declare -A _sfargs;for a in "${sfargs[@]}";do _sfsubst=${a//";"};_sfcount="$(((${#a} - ${#_sfsubst})))";if [ $_sfcount -eq 1 ];then read -r -a _sfparsearr<<<"${a}";_sfpargs+=("${_sfparsearr[0]}");_sfphead="$_sfphead ${_sfparsearr[0]}";_sfpdesc="$_sfpdesc ${_sfparsearr[0]};${_sfparsearr[1]}\n";elif [ $_sfcount -eq 2 ];then read -r -a _sfparsearr<<<"${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 [ $_sfcount -eq 4 ];then read -r -a _sfparsearr<<<"${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: $a";fi;done;[ "$sfparr" == true ]&&[ "${#_sfpargs[@]}" == 0 ]&&_sferr "At least one positional argument must be used with 'sfparr'";for e in "${sfexamples[@]}";do _sfsubst=${e//";"};_sfcount="$(((${#e} - ${#_sfsubst})))";if [ $_sfcount -eq 1 ];then read -r -a _sfparsearr<<<"${e}";_sfexamples="$_sfexamples ${_sfparsearr[0]};${_sfparsearr[1]}\n";else _sferr "Wrong example declaration: $e";fi;done;IFS=$OLDIFS;function _sfusage { echo -n "Usage: $(basename $0)";[ "$_sfodesc" != "" ]&&echo -n " [OPTIONS]";echo -ne "$_sfphead";[ "$sfparr" == true ]&&echo -n " ...";echo;[ ! -z ${sfdesc+x} ]&&echo -e "\n$sfdesc";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 "$@";do [ "$a" == "-h" ]||[ "$a" == "--help" ]&&_sfusage;done;while(("$#"));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]}="$1";[ "$sfparr" == true ]&&_sfplast="${_sfpargs[0]}"&&_sfparr=("$1");_sfpargs=("${_sfpargs[@]:1}");elif [ "$sfparr" == true ];then _sfparr+=("$1");else sferr "Too many positional arguments";fi;fi;fi;shift;done;[ "$sfparr" == true ]&&[ "${#_sfparr[@]}" -ge 1 ]&&read -r -a ${_sfplast}<<<"${_sfparr[@]}";if [ "$sfparr" != true ]&&[ ${#_sfpargs[@]} != 0 ];then for p in "${_sfpargs[@]}";do sferr "Positional argument '$p' missing" 0;done;exit 1;fi;unset a e _sfargs _sferr _sfexamples _sfflags _sfodesc _sfpargs _sfparr _sfpdesc _sfphead _sfplast _sfusage
#+end_src
** Requirements
- At least *Bash 4.x*
** Usage
The general usage for writing a script with /sf/ is:
1. Declare /sf/-variables at the top of your script
2. Include /sf/
3. Write your script with already parsed arguments, input functions, output functions and text formatting variables
*** 1. /sf/-variables
This is the list of variables which can be set *before* including /sf/.
Everything is optional.
| Name | Description | Example |
|--------------+-----------------------------------------------------------------------------------------------------+----------------------------------------|
| =sfdesc= | Description of the script | ~ sfdesc="This script does nothing." ~ |
| =sfargs= | Array for declaration of arguments, positional arguments and flags. Look below for more information | See [[#sfargs][below]] |
| =sfparr= | Flag which indicates if the last declared positional argument should be treated as array | ~ sfparr=true ~ |
| =sfexamples= | Array for declaration of examples for the usage output. Look below for more information | See also [[#sfexamples][below]] |
| =sfextra= | Additional usage output | ~ sfextra="No copyright." ~ |
Examples which show the usage of all variables can be found [[#examples][below]] and in the =examples= directory.
**** =sfargs=
:properties:
:custom_id: sfargs
:end:
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.
| Type | Declaration order | Example |
|---------------------+-----------------------------------------------------------------+---------------------------------------------------------|
| Positional argument | =<name>;<description>= | ~sfargs+=("FILE;File to read")~ |
| Flag | =<name>;<shorthand>;<description>= | ~sfargs+=("verbose;v;Enable verbose output")~ |
| Argument | =<name>;<shorthand>;<value_name>;<default_value>;<description>= | ~sfargs+=("text;t;TEXT;done;Print TEXT when finished")~ |
The order of declaration defines the order in the usage output.
**** =sfexamples=
:properties:
:custom_id: sfexamples
:end:
This is also an array of strings.
Examples are of the form =<command>;<description>= and can be added to /sf/ like this:
: sfexamples+=("count 8;Count to eight")
*** 2. Include /sf/
Grab the =sf= file from the repo, place it next to your script and source it with
#+begin_src sh
source "$(dirname $0)/sf"
#+end_src
*Or* just copy and paste the oneliner from above.
*** 3. Write your script
/sf/ deals with missing inputs and handles the parsing of arguments.
This means that after /sf/ was included *you can be sure that all variables have assigned values*.
Flags are either =false= or =true=, arguments have a provided value or the default value and positional arguments have a provided value.
The values are stored in variables with the name =$<name>=.
If you declared for example a flag like this:
#+begin_src sh
sfargs+=("verbose;v;Enable verbose output")
#+end_src
Then the variable =$verbose= exists with a value of either =false= or =true=.
**** Input functions
User input can be requested with two functions.
After calling a function, the user input is provided in the variable =$sfin=.
| =sfask= | Takes a string as input and asks for /yes/ or /no/. If an additional argument is provided (doesn't matter what), /no/ will be default. =$sfin= is either =true= or =false= |
| =sfget= | Takes a string as input and asks for user input. If a second argument is provided, this will be the default if no user input was entered |
Here is a small snippet to show the usage:
#+begin_src bash
sfget "Please enter your name" "John"
echo "Hello $sfin"
sfask "Do you want to proceed"
if [ "$sfin" == true ]; then
sfask "Are you sure" "no"
[ "$sfin" == true ] && echo "Please continue..." || echo "Bye"
else
echo "Bye"
fi
#+end_src
And the execution:
#+begin_example
Please enter your name [John]: Jane
Hello Jane!
Do you want to proceed? [Y/n]
Are you sure? [y/N] y
Please continue...
#+end_example
*Note* that the colon and question marks get added by the functions.
**** Output functions
Two output functions are provided which can be used to throw warnings and errors.
| =sfwarn= | Takes a string as input and prints a warning |
| =sferr= | Takes a string as input, prints an error and exits with code 1. If an additional argument is passed (doesn't matter what), it will just throw an error and don't exit |
**** Text formatting variables
The following text formatting variables can be used to modify the output:
| =sftrs= | Reset formatting |
| =sftbf= | Bold |
| =sftdim= | Dim |
| =sftul= | Underline |
| =sftblk= | Blinking |
| =sftinv= | Invert foreground/background |
| =sfthd= | Hidden |
| =sftclr= | Clear the previous line |
| =sftk= | Black |
| =sftr= | Red |
| =sftg= | Green |
| =sfty= | Yellow |
| =sftb= | Blue |
| =sftm= | Magenta |
| =sftc= | Cyan |
| =sftw= | White |
The variables can be used directly in =echo=, no =-e= needed.
To echo the word "framework" bold and red use the variables for example like this:
#+begin_src sh
echo "${sftbf}${sftr}framework${sftrs}"
#+end_src
** Examples
:properties:
:custom_id: examples
:end:
All examples can also be found in the =examples= directory.
Play around with the /sf/-variables and see what happens.
*** Count
This example script counts from/to a number:
#+begin_src sh
#!/usr/bin/env bash
# ----------------------
# sf -- script framework
# ----------------------
# Declare sf variables
sfdesc="A simple counter."
sfargs+=("N;Number to count")
sfargs+=("reverse;r;Count reverse")
sfargs+=("text;t;TEXT;done;Print TEXT when finished counting")
sfexamples+=("count 8;Count to eight")
sfexamples+=("count -r -t go 3;Count reverse from 3 and print 'go'")
sfextra="No copyright at all."
# Include sf, this could be replaced with a long oneliner
source "$(dirname $0)/sf"
# ----------------------
# Actual script
# ----------------------
if [ "$N" -ge 11 ]; then # Use parsed positional argument
sferr "I can only count to/from 10" # Throw an error and exit
fi
counter="$N" # Use parsed positional argument
echo -n "$sftbf" # Print everyting from here bold
while [ "$counter" -ge 1 ]; do
if [ "$reverse" == true ]; then # Use parsed flag
echo " $counter"
else
echo " $(expr $N - $counter + 1)" # Use parsed positional argument
fi
counter=$(expr $counter - 1)
sleep 1
done
echo -n "$sftrs" # Reset text formatting
echo "$text" # Use parsed argument
#+end_src
The usage output of the counter script is:
#+begin_example
Usage: count [OPTIONS] N
A simple counter.
POSITIONAL ARGUMENTS
N Number to count
OPTIONS
-r, --reverse Count reverse
-t, --text TEXT Print TEXT when finished counting (default: done)
EXAMPLES
count 8 Count to eight
count -r -t go 3 Count reverse from 3 and print 'go'
No copyright at all.
#+end_example
*** Add
This script adds numbers and shows the usage of =sfparr=:
#+begin_src sh
#!/usr/bin/env bash
# ----------------------
# sf -- script framework
# ----------------------
# Declare sf variables
sfdesc="Calculate the sum of multiple numbers."
sfargs+=("NUMBERS;Numbers which will be added")
sfargs+=("verbose;v;Enable verbose output")
sfparr=true # Treat the last declared positional argument as array
# Include sf, this could be replaced with a long oneliner
source "$(dirname $0)/sf"
# ----------------------
# Actual script
# ----------------------
sum=0
for n in "${NUMBERS[@]}"; do # Use parsed positional argument array
if [ "$verbose" == true ]; then # Use parsed flag
echo -n "$sum + $n = "
fi
sum="$(expr $sum + $n)"
if [ "$verbose" == true ]; then # Use parsed flag
echo "$sftbf$sum$sftrs" # Use text formatting variables
fi
done
echo "The sum is: $sftbf$sum$sftrs" # Use text formatting variables
#+end_src
And here is the produced usage:
#+begin_example
Usage: add [OPTIONS] NUMBERS ...
Calculate the sum of multiple numbers.
POSITIONAL ARGUMENTS
NUMBERS Numbers which will be added
OPTIONS
-v, --verbose Enable verbose output
#+end_example