| atof | converts a string to a double | 
    
      | atoi | converts a string to an
      integer | 
    
      | atol | converts a string to a long | 
    
      | isalnum | true if a character is
      alphanumeric | 
    
      | isalpha | true if a character is
      alphabetic | 
    
      | iscntrl | true if a character is a control
      character | 
    
      | isdigit | true if a character is a digit | 
    
      | isgraph | true if a character is a graphical
      character | 
    
      | islower | true if a character is
      lowercase | 
    
      | isprint | true if a character is a printing
      character | 
    
      | ispunct | true if a character is
      punctuation | 
    
      | isspace | true if a character is a space
      character | 
    
      | isupper | true if a character is an uppercase
      character | 
    
      | isxdigit | true if a character is a
      hexidecimal character | 
    
      | memchr | searches an array for the first
      occurance of a character | 
    
      | memcmp | compares two buffers | 
    
      | memcpy | copies one buffer to another | 
    
      | memmove | moves one buffer to another | 
    
      | memset | fills a buffer with a
      character | 
    
      | strcat | concatenates two strings | 
    
      | strchr | finds the first occurance of a
      character in a string | 
    
      | strcmp | compares two strings | 
    
      | strcoll | compares two strings in accordance
      to the current locale | 
    
      | strcpy | copies one string to another | 
    
      | strcspn | searches one string for any
      characters in another | 
    
      | strerror | returns a text version of a given
      error code | 
    
      | strlen | returns the length of a given
      string | 
    
      | strncat | concatenates a certain amount of
      characters of two strings | 
    
      | strncmp | compares a certain amount of
      characters of two strings | 
    
      | strncpy | copies a certain amount of
      characters from one string to another | 
    
      | strpbrk | finds the first location of any
      character in one string, in another string | 
    
      | strrchr | finds the last occurance of a
      character in a string | 
    
      | strspn | returns the length of a substring
      of characters of a string | 
    
      | strstr | finds the first occurance of a
      substring of characters | 
    
      | strtod | converts a string to a double | 
    
      | strtok | finds the next token in a
      string | 
    
      | strtol | converts a string to a long | 
    
      | strtoul | converts a string to an unsigned
      long | 
    
      | strxfrm | converts a substring so that it can
      be used by string comparison functions | 
    
      | tolower | converts a character to
      lowercase | 
    
      | toupper | converts a character to
      uppercase |