first

Return the first character(s) of a string.

Installation

To use as a general utility, install the CLI package globally

npm install -g @stdlib/string-first-cli

Usage

Usage: first [options] [<string>]

Options:

  -h,    --help                Print this message.
  -V,    --version             Print the package version.
         --n num               Number of characters to return. Default: 1.
         --split sep           Delimiter for stdin data. Default: '/\\r?\\n/'.
         --mode mode           Type of character to return. Default: 'grapheme'.

Notes

• If the split separator is a regular expression, ensure that the split option is either properly escaped or enclosed in quotes.

  # Not escaped...
  $ echo -n $'beep\nboop' | first --split /\r?\n/
  
  # Escaped...
  $ echo -n $'beep\nboop' | first --split /\\r?\\n/

• The implementation ignores trailing delimiters.

Examples

$ first beep
b

To use as a standard stream,

$ echo -n 'beep\nboop' | first --n=2
be
bo

By default, when used as a standard stream, the implementation assumes newline-delimited data. To specify an alternative delimiter, set the split option.

$ echo -n 'beep\tboop' | first --split '\t'
b
b

See Also

• @stdlib/string-first: return the first character(s) of a string.
• @stdlib/string-remove-first: remove the first character(s) of a string.
• @stdlib/string-last: return the last character(s) of a string.

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.