cppreference.com > Standard C String and Character > isgraph isgraph Syntax:
      #include <ctype.h>
      int isgraph( int ch );
The function isgraph() returns non-zero if its argument is any printable character other than a space (if you can see the character, then isgraph() will return a non-zero value). Otherwise, zero is returned. Related topics: isalnum isalpha iscntrl isdigit isprint ispunct isspace isxdigit