allspace.c

[詳解]

/*++
/* NAME
/*  allspace 3
/* SUMMARY
/*  predicate if string is all space
/* SYNOPSIS
/*  #include <stringops.h>
/*
/*  int allspace(buffer)
/*  const char *buffer;
/* DESCRIPTION
/*  allspace() determines if its argument is an all-space string.
/*
/*  Arguments:
/* .IP buffer
/*  The null-terminated input string.
/* LICENSE
/* .ad
/* .fi
/*  The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*--*/

/* System library. */

#include <sys_defs.h>
#include <ctype.h>

/* Utility library. */

#include "stringops.h"

/* allspace - return true if string is all space */

int     allspace(const char *string)
{
    const char *cp;
    int     ch;

    if (*string == 0)
    return (0);
    for (cp = string; (ch = *(unsigned char *) cp) != 0; cp++)
    if (!ISASCII(ch) || !ISSPACE(ch))
        return (0);
    return (1);
}