isgraph —
printing character test (space character exclusive)
Standard C Library (libc, -lc)
#include <ctype.h>
int
  
  isgraph(int
    c);
The isgraph() function tests for any printing character
  except space (' ').
The isgraph() function returns zero if the character
  tests false and returns non-zero if the character tests true.
ctype(3),
  isalnum(3),
  isalpha(3),
  isascii(3),
  isblank(3),
  iscntrl(3),
  isdigit(3),
  islower(3),
  isprint(3),
  ispunct(3),
  isspace(3),
  isupper(3),
  isxdigit(3),
  stdio(3),
  toascii(3),
  tolower(3),
  toupper(3),
  ascii(7)
The isgraph() function conforms to ANSI
  X3.159-1989 (“ANSI C89”).
The argument to isgraph() must be
  EOF or representable as an unsigned
  char; otherwise, the behavior is undefined. See the
  CAVEATS section of
  ctype(3) for more details.