Standard C String and Character

atofconverts a string to a double
atoiconverts a string to an integer
atolconverts a string to a long
isalnumtrue iff a character is alphanumeric
isalphatrue iff a character is alphabetic
iscntrltrue iff a character is a control character
isdigittrue iff a character is a digit
isgraphtrue iff a character is a graphical character
islowertrue iff a character is lowercase
isprinttrue iff a character is a printing character
ispuncttrue iff a character is punctuation
isspacetrue iff a character is a space character
isuppertrue iff a character is an uppercase character
isxdigittrue iff a character is a hexadecimal character
memchrsearches an array for the first occurrence of a character
memcmpcompares two buffers
memcpycopies one buffer to another
memmovemoves one buffer to another
memsetfills a buffer with a character
strcatconcatenates two strings
strchrfinds the first occurrence of a character in a string
strcmpcompares two strings
strcollcompares two strings in accordance to the current locale
strcpycopies one string to another
strcspnsearches one string for any characters in another
strerrorreturns a text version of a given error code
strlenreturns the length of a given string
strncatconcatenates a certain amount of characters of two strings
strncmpcompares a certain amount of characters of two strings
strncpycopies a certain amount of characters from one string to another
strpbrkfinds the first location of any character in one string, in another string
strrchrfinds the last occurrence of a character in a string
strspnreturns the length of a substring of characters of a string
strstrfinds the first occurrence of a substring of characters
strtodconverts a string to a double
strtokfinds the next token in a string
strtolconverts a string to a long
strtoulconverts a string to an unsigned long
strxfrmconverts a substring so that it can be used by string comparison functions
tolowerconverts a character to lowercase
toupperconverts a character to uppercase