String::Util -- String processing utilities

- NAME
- SYNOPSIS
- DESCRIPTION
- INSTALLATION
- FUNCTIONS
  - collapse($string), crunch($string)
  - hascontent($scalar), nocontent($scalar)
  - trim($string)
  - ltrim, rtrim
  - no_space($string)
  - htmlesc(string)
  - cellfill($string)
  - jsquote($string)
  - unquote($string)
  - define($scalar)
  - repeat($string, $count)
  - randword($length, %options)
  - eqq($val1, $val2)
  - neqq($string1, $string2)
  - equndef(), neundef()
  - fullchomp($string)
  - randcrypt($string)
  - randpost(%opts)
  - ords($string)
  - deords($string)
  - contains($string, $substring)
  - startswith($string, $substring)
  - endswith($string, $substring)
  - crunchlines($string)
- TERMS AND CONDITIONS
- AUTHORS

# NAME

String::Util -- String processing utilities

# SYNOPSIS

      use String::Util ':all';

      # "crunch" whitespace and remove leading/trailing whitespace
      $val = crunch($val);

      # does this value have "content", i.e. it's defined
      # and has something besides whitespace?
      if (hascontent $val) {...}

      # format for display in a web page
      $val = htmlesc($val);

      # format for display in a web page table cell
      $val = cellfill($val);

      # remove leading/trailing whitespace
      $val = trim($val);

      # ensure defined value
      $val = define($val);

      # repeat string x number of times
      $val = repeat($val, $iterations);

      # remove leading/trailing quotes
      $val = unquote($val);

      # remove all whitespace
      $val = no_space($val);

      # remove trailing \r and \n, regardless of what
      # the OS considers an end-of-line
      $val = fullchomp($val);

      # or call in void context:
      fullchomp $val;

      # encrypt string using random seed
      $val = randcrypt($val);

      # are these two values equal, where two undefs count as "equal"?
      if (eqq $a, $b) {...}

      # are these two values different, where two undefs count as "equal"?
      if (neqq $a, $b) {...}

      # get a random string of some specified length
      $val = randword(10);

# DESCRIPTION

String::Util provides a collection of small, handy utilities for processing strings.

# INSTALLATION

String::Util can be installed with the usual routine:

     perl Makefile.PL
     make
     make test
     make install

# FUNCTIONS

## collapse($string), crunch($string)

`collapse()` collapses all whitespace in the string down to single spaces. Also removes all leading and trailing whitespace. Undefined input results in undefined output.

`crunch()` is the old name for `collapse()`. I decided that "crunch" never sounded right. Spaces don't go "crunch", they go "poof" like a collapsing ballon. However, `crunch()` will continue to work as an alias for `collapse()`.

## hascontent($scalar), nocontent($scalar)

hascontent() returns true if the given argument is defined and contains something besides whitespace.

An undefined value returns false. An empty string returns false. A value containing nothing but whitespace (spaces, tabs, carriage returns, newlines, backspace) returns false. A string containing any other characters (including zero) returns true.

`nocontent()` returns the negation of `hascontent()`.

## trim($string)

Returns the string with all leading and trailing whitespace removed. Trim on undef returns "".

So, for example, the following code changes " my string " to "my string":

     $var = " my string  ";
     $var = trim($var);

trim accepts two optional arguments, 'left' and 'right', both of which are true by default. So, to avoid trimming the left side of the string, set the 'left' argument to false:

     $var = trim($var, left=>0);

To avoid trimming the right side, set 'right' to false:

     $var = trim($var, right=>0);

## ltrim, rtrim

ltrim trims leading whitespace. rtrim trims trailing whitespace. They are exactly equivalent to

     trim($var, left=>0);

and

     trim($var, right=>0);

## no_space($string)

Removes all whitespace characters from the given string.

## htmlesc(string)

Formats a string for literal output in HTML. An undefined value is returned as an empty string.

htmlesc() is very similar to CGI.pm's escapeHTML. However, there are a few differences. htmlesc() changes an undefined value to an empty string, whereas escapeHTML() returns undefs as undefs.

## cellfill($string)

Formats a string for literal output in an HTML table cell. Works just like htmlesc() except that strings with no content (i.e. are undef or are just whitespace) are returned as `&nbsp;`.

## jsquote($string)

Escapes and quotes a string for use in JavaScript. Escapes single quotes and surrounds the string in single quotes. Returns the modified string.

## unquote($string)

If the given string starts and ends with quotes, removes them. Recognizes single quotes and double quotes. The value must begin and end with same type of quotes or nothing is done to the value. Undef input results in undef output. Some examples and what they return:

     unquote(q|'Hendrix'|);   # Hendrix
     unquote(q|"Hendrix"|);   # Hendrix
     unquote(q|Hendrix|);     # Hendrix
     unquote(q|"Hendrix'|);   # "Hendrix'
     unquote(q|O'Sullivan|);  # O'Sullivan

option: braces

If the braces option is true, surrounding braces such as [] and {} are also removed. Some examples:

     unquote(q|[Janis]|, braces=>1);  # Janis
     unquote(q|{Janis}|, braces=>1);  # Janis
     unquote(q|(Janis)|, braces=>1);  # Janis

## define($scalar)

Takes a single value as input. If the value is defined, it is returned unchanged. If it is not defined, an empty string is returned.

This subroutine is useful for printing when an undef should simply be represented as an empty string. Perl already treats undefs as empty strings in string context, but this subroutine makes the warnings module go away. And you ARE using warnings, right?

## repeat($string, $count)

Returns the given string repeated the given number of times. The following command outputs "Fred" three times:

     print repeat('Fred', 3), "\n";

Note that repeat() was created a long time based on a misunderstanding of how the perl operator 'x' works. The following command using 'x' would perform exactly the same as the above command.

     print 'Fred' x 3, "\n";

Use whichever you prefer.

## randword($length, %options)

Returns a random string of characters. String will not contain any vowels (to avoid distracting dirty words). First argument is the length of the return string. So this code:

     foreach my $idx (1..3) {
       print randword(4), "\n";
     }

would output something like this:

     kBGV
     NCWB
     3tHJ

If the string 'dictionary' is sent instead of an integer, then a word is randomly selected from a dictionary file. By default, the dictionary file is assumed to be at /usr/share/dict/words and the shuf command is used to pull out a word. The hash %String::Util::PATHS sets the paths to the dictionary file and the shuf executable. Modify that hash to change the paths. So this code:

     foreach my $idx (1..3) {
       print randword('dictionary'), "\n";
     }

would output something like this:

     mustache
     fronds
     browning

option: alpha

If the alpha option is true, only alphabetic characters are returned, no numerals. For example, this code:

     foreach my $idx (1..3) {
       print randword(4, alpha=>1), "\n";
     }

would output something like this:

     qrML
     wmWf
     QGvF

option: numerals

If the numerals option is true, only numerals are returned, no alphabetic characters. So this code:

     foreach my $idx (1..3) {
       print randword(4, numerals=>1), "\n";
     }

would output something like this:

     3981
     4734
     2657

option: strip_vowels

This option is true by default. If true, vowels are not included in the returned random string. So this code:

     foreach my $idx (1..3) {
       print randword(4, strip_vowels=>1), "\n";
      }

would output something like this:

     Sk3v
     pV5z
     XhSX

## eqq($val1, $val2)

Returns true if the two given values are equal. Also returns true if both are undef. If only one is undef, or if they are both defined but different, returns false. Here are some examples and what they return.

     eqq('x', 'x'), "\n";      # 1
     eqq('x', undef), "\n";    # 0
     eqq(undef, undef), "\n";  # 1

## neqq($string1, $string2)

The opposite of neqq, returns true if the two values are *not* the same. Here are some examples and what they return.

     print neqq('x', 'x'), "\n";      # 0
     print neqq('x', undef), "\n";    # 1
     print neqq(undef, undef), "\n";  # 0

## equndef(), neundef()

equndef() has been renamed to eqq(). neundef() has been renamed to neqq(). Those old names have been kept as aliases.

## fullchomp($string)

Works like chomp, but is a little more thorough about removing \n's and \r's even if they aren't part of the OS's standard end-of-line.

Undefs are returned as undefs.

## randcrypt($string)

Crypts the given string, seeding the encryption with a random two character seed.

## randpost(%opts)

Returns a string that sorta looks like one or more paragraphs.

option: word_count

Sets how many words should be in the post. By default a random number from 1 to 250 is used.

option: par_odds

Sets the odds of starting a new paragraph after any given word. By default the value is .05, which means paragraphs will have an average about twenty words.

option: par

Sets the string to put at the end or the start and end of a paragraph. Defaults to two newlines for the end of a pargraph.

If this option is a single scalar, that string is added to the end of each paragraph.

To set both the start and end string, use an array reference. The first element should be the string to put at the start of a paragraph, the second should be the string to put at the end of a paragraph.

option: max_length

Sets the maximum length of the returned string, including paragraph delimiters.

## ords($string)

Returns the given string represented as the ascii value of each character.

For example, this code:

     ords('Hendrix')

returns this string:

     {72}{101}{110}{100}{114}{105}{120}

options

- convert_spaces=>[true|false]

  If convert_spaces is true (which is the default) then spaces are converted to their matching ord values. So, for example, this code:

       ords('a b', convert_spaces=>1)

  returns this:

  {97}{32}{98}

  This code returns the same thing:

       ords('a b')

  If convert_spaces is false, then spaces are just returned as spaces. So this code:

       ords('a b', convert_spaces=>0);

  returns

       {97} {98}

- alpha_nums

  If the alpha_nums option is false, then characters 0-9, a-z, and A-Z are not converted. For example, this code:

       ords('a=b', alpha_nums=>0)

  returns this:

       a{61}b

## deords($string)

Takes the output from ords() and returns the string that original created that output.

For example, this command:

     deords('{72}{101}{110}{100}{114}{105}{120}')

returns this string: Hendrix

## contains($string, $substring)

Checks if the string contains substring

Examples:

      contains("Hello world", "Hello");   # true
      contains("Hello world", "llo wor"); # true
      contains("Hello world", "QQQ");     # false

## startswith($string, $substring)

Checks if the string starts with the characters in substring

Examples:

      startwidth("Hello world", "Hello"); # true
      startwidth("Hello world", "H");     # true
      startwidth("Hello world", "Q");     # false

## endswith($string, $substring)

Checks if the string ends with the characters in substring

Examples:

      endswidth("Hello world", "world");   # true
      endswidth("Hello world", "d");       # true
      endswidth("Hello world", "QQQ");     # false

## crunchlines($string)

Compacts contiguous newlines into single newlines. Whitespace between newlines is ignored, so that two newlines separated by whitespace is compacted down to a single newline.

For example, this code:

     crunchlines("x\n\n\nx")

outputs two x's with a single empty line between them:

     x

     x

# TERMS AND CONDITIONS

Copyright (c) 2012-2016 by Miko O'Sullivan. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. This software comes with NO WARRANTY of any kind.

# AUTHORS

Miko O'Sullivan miko@idocs.com

Scott Baker scott@perturb.org