ctype.c

一个小型的操作系统,采用gcc进行开发,几千行的代码,方便初学者学习

/*
*  Snixos Project version 1.0, 2003.6
*  (C) Copyright 2003,2004,2005 Jockeyson,KeqiangGao <[e-mail]>
*  All Rights Reserved.
*  Distributed under the terms of the GNU General Public License.
*
*  This program is a free and open source software and you can redistribute 
*  it and/or modify it under the terms of the GNU General Public License as
*  published by the Free Software Foundation. As no any liability is assumed 
*  for any incidental or consequential damages in connection with the 
*  information or program fragments contained herein,so any exception arised
*  is at your own risk. It is ABSOLUTELY WITHOUT ANY WARRANTY.
*  Bug report please send to [e-mail] .
*/
/*
  ctype.c: implementation of ctype.c for snixos 
  Author : [e-mail]
  Time:    2003.6
*/ 
    
    
/* isalnum -- true return argument is valid ASCII alphabetic or digit */ 
int isalnum(char c) 
{
    return ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || 
	     (c >= '0' && c <= '9'));
}


/* isalpha -- true return argument is valid ASCII alphabetic */ 
int isalpha(char c) 
{
    return ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'));
}


/* isascii -- true return argument is valid ASCII character */ 
int isascii(char c) 
{
    return (((unsigned) c) <= 127);
} int isblank(char c) 
{
    return (c == '\t' || c == ' ');
}


/* iscntrl -- true return argument is valid ASCII control character */ 
int iscntrl(char c) 
{
    return (c < ' ' || c == 127);
}


/* isdigit -- true return argument is valid ASCII digit */ 
int isdigit(char c) 
{
    return (c >= '0' && c <= '9');
}


/* isgraph  return true for all printable char except space (0x20h) and 0x7f */ 
int isgraph(char c) 
{
    return (c > 0x20 && c < 0x7f);
}


/* islower -- true return argument is valid ASCII lower case alphabetic */ 
int islower(char c) 
{
    return (c >= 'a' && c <= 'z');
}


/* isprint -- true return argument is valid ASCII graphic */ 
int isprint(char c) 
{
    return (c >= ' ' && c <= 126);
}


/* ispunct -- true return argument is neither ASCII control or alphabetic */ 
/*
!(21) "(22) #(23) $(24) %(25) &(26) '(27) ((28) )(29) *(2a) +(2b) 
,(2c) -(2d) .(2e) /(2f) :(3a) ;(3b) <(3c) =(3d) >(3e) ?(3f) @(40) [(5b) 
\(5c) ](5d) ^(5e) _(5f) `(60) {(7b) |(7c) }(7d) ~(7e)
*/ 
int ispunct(char c) 
{
    return (c >= 0x21 && c <= 0x2f || c >= 0x3a && c <= 0x40 || c >= 0x5b
	     && c <= 0x60 || c >= 0x7b && c <= 0x7e);
}


/* isspace -- true return argument is ASCII space, tab, carriage return,
              newline (line feed), or form feed  (ie, "white space") */ 
int isspace(char c) 
{
    return (c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == '\f'
	     || c == '\v');
}


/* isupper -- true return argument is valid ASCII upper case alphabetic */ 
int isupper(char c) 
{
    return (c >= 'A' && c <= 'Z');
}


/* isxdigit return true if c is a hex digit */ 
int isxdigit(char c) 
{
    return (isdigit(c) || c >= 'a' && c <= 'f' || c >= 'A' && c <= 'F');
}


/* toascii: convert char to ascii ranaged:0~127 */ 
int toascii(char c) 
{
    return (((unsigned) c) & 0x7f);
} 

/* tolower: convert uppercase to lowercase for letter 'A'~'Z' */ 
int tolower(char c) 
{
    return (isupper(c) ? c | 0x20 : c);
}


/* toupper: convert lowercase to uppercase for letter 'a'~'z' */ 
int toupper(char c) 
{
    return (islower(c) ? c & 0xdf : c);
}