2016-09-11 research

New Shell Scripting Language: The Looks

So we have established that BASH sucks, certain things need to go, and we need to replace it with a new and improved shell language. But what should this new language look like?

Variables:

string $url = "http://blahblah.com" // strict typing; `$` denotes variable
int $day = 35 // newline delimits commands
bool $is_True = True // `True` and `False` are keywords
float $salary = 5600.00
string $find = { find, $dir, -type f } 
    // can set return values of commands to variables

Running Commands:

[ firefox, $url ] // plain words are assumed to be commands, `$` denotes variable
[ wget, $url ]
[ pkill, -9, $pid ] // options are given after command name, preceded by `-`

Nested commands:

[ [ find, $dir, -type f, -printf "%p %s\n", 2>/dev/null ],
  |, 
  [ sed, 's/.*\/[^.]*\.//' ] ]

Equivalent expression in BASH:

find $DIR -type f -printf "%p %s\n" 2>/dev/null | sed 's/.*\/[^.]*\.//'

Functions:

string summary() [ // functions have strict return types
    return [ [ df, -Th, $dir,
             |,
             [ tail, -1 ],
             [ awk, '{print $1, $2, $5, $6;}' ],
             |,
             [ column, -t]
           ]
]

Semi-equivalent function in BASH (no return value):

summary(){
    df -Th $DIR | tail -1 | awk '{print $1, $2, $5, $6;}' | column -t
}

Conditionals:

if ( $var is True ) // condition in parentheses for easy parsing
[ // commands inside of square brackets for consistency and more easy parsing
    int $month = 9
    int $day = 11
    float $money = 32.32
    [ [ ps, -aux ], |, [grep, $money] ] // nested brackets for each command 
] 

switch ($key) [
    case ('-h' | '--help') [
        $HELP = True
    ]
    case ( '-f', '--file') [
        $FILE = True
    ]
    default [
        $HELP = True
    ]
]

Equivalent case structure in BASH:

key="$1"
case $key in
    -h|--help)
        HELP=true
        ;;
    -f|--file)
        FILE="$2"
        shift
        ;;
    *)
        HELP=true
        ;;
esac

Loops:

for ( $i = 0, $i < 10, $i++) [
    [ echo, $i ]
]

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