isprint() - printing character test (space character inclusive)
#include <ctype.h>
int isprint (int c)
The isprint(3) function tests for any printing character including space (' ').
The isprint(3) function returns zero if the character tests false and returns non-zero if the character tests true.
isalnum(3)
isalpha(3)
isblank(3)
iscntrl(3)
isdigit(3)
isgraph(3)
islower(3)
ispunct(3)
isspace(3)
isupper(3)
isxdigit(3)
tolower(3)
toupper(3)