PHP/string

The official PHP docs don't really organize the string-functions listing very well.

		categories
fx() name	description	escaping	int output	encryption	formatting	output
addcslashes	Quote string with slashes in a C style	Y
addslashes	Quote string with slashes	Y
chop	Alias of rtrim
count_chars	Return information about characters used in a string		Y
crc32	Calculates the crc32 polynomial of a string		Y	Y
crypt	One-way string hashing			Y
fprintf	Write a formatted string to a stream			Y	stream
localeconv — Get numeric formatting information
ltrim — Strip whitespace (or other characters) from the beginning of a string
md5_file — Calculates the md5 hash of a given file
md5 — Calculate the md5 hash of a string
money_format — Formats a number as a currency string
nl2br — Inserts HTML line breaks before all newlines in a string
number_format — Format a number with grouped thousands
ord — Convert the first byte of a string to a value between 0 and 255
parse_str — Parses the string into variables
print — Output a string
printf — Output a formatted string
quoted_printable_decode — Convert a quoted-printable string to an 8 bit string
quoted_printable_encode — Convert a 8 bit string to a quoted-printable string
quotemeta — Quote meta characters
rtrim — Strip whitespace (or other characters) from the end of a string
setlocale — Set locale information
sha1_file — Calculate the sha1 hash of a file
sha1 — Calculate the sha1 hash of a string
similar_text — Calculate the similarity between two strings
soundex — Calculate the soundex key of a string
sprintf — Return a formatted string
sscanf — Parses input from a string according to a format
str_contains — Determine if a string contains a given substring
str_ends_with — Checks if a string ends with a given substring
str_getcsv — Parse a CSV string into an array
str_ireplace — Case-insensitive version of str_replace
str_pad — Pad a string to a certain length with another string
str_repeat — Repeat a string
str_replace — Replace all occurrences of the search string with the replacement string
str_rot13 — Perform the rot13 transform on a string
str_shuffle — Randomly shuffles a string
str_split — Convert a string to an array
str_starts_with — Checks if a string starts with a given substring
str_word_count — Return information about words used in a string
strcasecmp — Binary safe case-insensitive string comparison
strchr — Alias of strstr
strcmp — Binary safe string comparison
strcoll — Locale based string comparison
strcspn — Find length of initial segment not matching mask
strip_tags — Strip HTML and PHP tags from a string
stripcslashes — Un-quote string quoted with addcslashes
stripos — Find the position of the first occurrence of a case-insensitive substring in a string
stripslashes — Un-quotes a quoted string
stristr — Case-insensitive strstr
strlen — Get string length
strnatcasecmp — Case insensitive string comparisons using a "natural order" algorithm
strnatcmp — String comparisons using a "natural order" algorithm
strncasecmp — Binary safe case-insensitive string comparison of the first n characters
strncmp	Binary safe string comparison of the first n characters
strpbrk	Search a string for any of a set of characters
strpos	Find the position of the first occurrence of a substring in a string
strrchr	Find the last occurrence of a character in a string
strrev	Reverse a string
strripos	Find the position of the last occurrence of a case-insensitive substring in a string
strrpos	Find the position of the last occurrence of a substring in a string
strspn	Finds the length of the initial segment of a string consisting entirely of characters contained within a given mask
strstr	Find the first occurrence of a string
strtok	Tokenize string
strtolower	Make a string lowercase
strtoupper	Make a string uppercase
strtr	Translate characters or replace substrings
substr_compare	Binary safe comparison of two strings from an offset, up to length characters
substr_count	Count the number of substring occurrences
substr_replace	Replace text within a portion of a string
substr	Return part of a string
trim	Strip whitespace (or other characters) from the beginning and end of a string
ucfirst	Make a string's first character uppercase
ucwords	Uppercase the first character of each word in a string
utf8_decode	Converts a string from UTF-8 to ISO-8859-1, replacing invalid or unrepresentable characters
utf8_encode	Converts a string from ISO-8859-1 to UTF-8
vfprintf	Write a formatted string to a stream
vprintf	Output a formatted string
vsprintf	Return a formatted string
wordwrap	Wraps a string to a given number of characters

Splitting/Joining

fx() name	description
chunk_split	Split a string into smaller chunks
explode	Split a string by a string
implode	Join array elements with a string
join	Alias of implode

Single Character

fx() name	description
chr	Generate a single-byte string from a number
lcfirst	Make a string's first character lowercase

Fuzzy

fx() name	description
levenshtein	Calculate Levenshtein distance between two strings
metaphone	Calculate the metaphone key of a string

Conversion

fx() name	description	conversion format
bin2hex	Convert binary data into hexadecimal representation	hexadecimal
convert_cyr_string	Convert from one Cyrillic character set to another	Cyrillic
convert_uudecode	Decode a uuencoded string	Template:L/wp
convert_uuencode	Uuencode a string	Template:L/wp
get_html_translation_table	Returns the translation table used by htmlspecialchars and htmlentities	HTML
hebrev	Convert logical Hebrew text to visual text	Hebrew
hebrevc	Convert logical Hebrew text to visual text with newline conversion	Hebrew
hex2bin	Decodes a hexadecimally encoded binary string	hexadecimal
html_entity_decode	Convert HTML entities to their corresponding characters	HTML
htmlentities	Convert all applicable characters to HTML entities	HTML
htmlspecialchars_decode	Convert special HTML entities back to characters	HTML
htmlspecialchars	Convert special characters to HTML entities	HTML
nl_langinfo — Query language and locale information	locale