CODEWITHSUNDEEP
parametersparameter-passingfish
Andrew Matthews
Andrew Matthews

Reputation: 3146

passing whole strings as arguments in fish shell

I have a number of cases where I need to pass free-form (i.e. containing white space and symbols as well as alphabetical symbols) strings as parameters to a function in fish shell.

Here's an example where I try to use getopts (to no avail):

function create_a_note --description 'create a new text note'
    
  set -l title ''
  set -l tags ''

  getopts $argv | while read -l key value
      switch $key
          case t title
              set title $value
          case g tags
              set tags $value
      end
  end

  if test -z $title
    error "title must be set (use the -t option)" >&2
    return 1
  end

  # do something interesting with the title and tags
end

I invoke it like this:

create_a_note -t 'my very interesting note' -g '@blah @rhubarb'

Whenever I use this kind of approach, the variables $title and $tags get the first word of the strings (i.e. $title == 'my' and $tags == '@blah') rather than the whole string. I get why this is happening, where the string is converted to a list and the first element of the list is returned.

My question is - is there a way around this within fish shell? I don't want to just pass in $argv and parse it myself unless there is no other option.

Use of getopts is optional, if you'll pardon the pun.

Upvotes: 0

Views: 1151

Answers (2)

Base64__
Base64__

Reputation: 107

I think you would need to use double quotes: $example == "example text w/ spaces and quotes". Or you might need to escape the spaces: $example == 'example\ text\ w/\ spaces\ and\ backslashes'. Also, if Wikipedia is anything to go by, every variable is an array so you might need get the array content instead of the first value in the array, which is what I think is happening.

EDIT: I didn't read the question correctly. In any case the solution would be almost the same:

  • Quotes: create_a_note -t "my very interesting note" -g "@blah @rhubarb"
  • Escape" create_a_note -t my\ very\ interesting\ note -g @blah\ @rhubarb

Upvotes: 2

Zanchey
Zanchey

Reputation: 2040

My suggestion is to stop using getopts, an interface which I can never get right, and instead use fish's built-in argument parsing tool, argparse.

function create_a_note --description 'create a new text note'
    
  set -l title ''
  set -l tags ''
  argparse 't/=+' 'g/=+' -- $argv
                       
  if test -z "$_flag_t"
    echo "title must be set (use the -t option)" >&2
    return 1               
  end                      
                           
  echo $_flag_t; echo $_flag_g
end

In particular, argparse 't/=+' 'g/=+' means "a -t option which requires an argument, and a -g option which requires an argument". These arguments are stored in $_flag_t and $_flag_g respectively. There's more information in the argparse manual.

Upvotes: 3

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