substringBefore

Return the part of a string before a specified substring.

Installation

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

npm install -g @stdlib/string-substring-before-cli

Usage

Usage: substring-before [options] --search=<string> [<string>]

Options:

  -h,    --help                Print this message.
  -V,    --version             Print the package version.
         --search string       Search string.
         --split sep           Delimiter for stdin data. Default: '/\\r?\\n/'.

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 $'foo\nbar\nbaz' | substring-before --search a --split /\r?\n/
  
  # Escaped...
  $ echo -n $'foo\nbar\nbaz' | substring-before --search a --split /\\r?\\n/

• The implementation ignores trailing delimiters.

Examples

$ substring-before abcdefg --search d
abc

To use as a standard stream,

$ echo -n $'beep\nboop' | substring-before --search p
bee
boo

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' | substring-before --search p --split '\t'
bee
boo

See Also

• @stdlib/string-substring-before: return the part of a string before a specified substring.
• @stdlib/string-substring-before-cli-last: return the part of a string before the last occurrence of a specified substring.
• @stdlib/string-substring-after: return the part of a string after a specified substring.
• @stdlib/string-substring-after-last: return the part of a string after the last occurrence of a specified substring.

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.