characters.(1) - phpMan

_tolower (3p)        - transliterate uppercase characters to lowercase
_toupper (3p)        - transliterate lowercase characters to uppercase
fgetc (3)            - input of characters and strings
fgets (3)            - input of characters and strings
fputc (3)            - output of characters and strings
fputs (3)            - output of characters and strings
getc (3)             - input of characters and strings
getchar (3)          - input of characters and strings
gets (3)             - input of characters and strings
putc (3)             - output of characters and strings
putchar (3)          - output of characters and strings
puts (3)             - output of characters and strings
strings (1)          - print the strings of printable characters in files.
tolower (3p)         - transliterate uppercase characters to lowercase
toupper (3p)         - transliterate lowercase characters to uppercase
ungetc (3)           - input of characters and strings
wcpncpy (3)          - copy a fixed-size string of wide characters, returning...
wmemcmp (3p)         - compare wide characters in memory
wmemcpy (3p)         - copy wide characters in memory
wmemmove (3p)        - copy wide characters in memory with overlapping areas
wmemset (3)          - fill an array of wide-characters with a constant wide ...
wmemset (3p)         - set wide characters in memory