strerror.c

上一个上传的有问题,这个是好的。visopsys包括系统内核和GUI的全部SOURCE code ,还包括一些基本的docs文档。里面src子目录对应所有SOURCE code.对于想研究操作系统的朋

// 
//  Visopsys
//  Copyright (C) 1998-2007 J. Andrew McLaughlin
//  
//  This library is free software; you can redistribute it and/or modify it
//  under the terms of the GNU Lesser General Public License as published by
//  the Free Software Foundation; either version 2.1 of the License, or (at
//  your option) any later version.
//
//  This library is distributed in the hope that it will be useful, but
//  WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser
//  General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public License
//  along with this library; if not, write to the Free Software Foundation,
//  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
//  strerror.c
//

// This "strerror" function is similar in function to the one found in
// other standard C libraries

#include <string.h>
#include <errno.h>


static struct {
    int code;
    char *string;
} errorStringTable[] = {
    { 0, "No error." },
    { ERR_INVALID, "Invalid operation." },
    { ERR_PERMISSION, "Permission denied." },
    { ERR_MEMORY, "Memory allocation or freeing error." },
    { ERR_BUSY, "The resource is busy." },
    { ERR_NOSUCHENTRY, "Object does not exist." },
    { ERR_BADADDRESS, "Invalid memory address." },
    { ERR_NOTINITIALIZED, "Resource has not been initialized." },
    { ERR_NOTIMPLEMENTED, "Requested functionality not implemented." },
    { ERR_NULLPARAMETER, "Required parameter was NULL." },
    { ERR_NODATA, "No data supplied." },
    { ERR_BADDATA, "Corrupt data encountered." },
    { ERR_ALIGN, "Memory alignment error." },
    { ERR_NOFREE, "No free resources." },
    { ERR_DEADLOCK, "Deadlock situation avoided." },
    { ERR_PARADOX, "Requested action is paradoxical." },
    { ERR_NOLOCK, "Resource lock could not be obtained." },
    { ERR_NOVIRTUAL, "Virtual memory error." },
    { ERR_EXECUTE, "Command could not be executed." },
    { ERR_NOTEMPTY, "Object is not empty." },
    { ERR_NOCREATE, "Cannot create." },
    { ERR_NODELETE, "Cannot delete." },
    { ERR_IO, "Device input/output error." },
    { ERR_BOUNDS, "Out of bounds error." },
    { ERR_ARGUMENTCOUNT, "Incorrect number of parameters." },
    { ERR_ALREADY, "Requested action is unnecessary." },
    { ERR_DIVIDEBYZERO, "Divide by zero error." },
    { ERR_DOMAIN, "Math operation is not in the domain" },
    { ERR_RANGE, "Math operation is out of range" },
    { ERR_KILLED, "Process killed" },
    { ERR_NOMEDIA, "No media present" },
    { ERR_NOSUCHFILE, "No such file." },
    { ERR_NOSUCHDIR, "No such directory." },
    { ERR_NOTAFILE, "Object is not a file." },
    { ERR_NOTADIR, "Object is not a directory." },
    { ERR_NOWRITE, "Cannot write data." },
    { ERR_NOSUCHUSER, "No such user." },
    { ERR_NOSUCHPROCESS, "No such process." },
    { ERR_NOSUCHDRIVER, "There is no driver for this operation." },
    { ERR_NOSUCHFUNCTION, "Operation not supported." },
    { ERR_BUG, "Internal error (bug)." },
    { 0, NULL }
};


char *strerror(int error)
{
  // Returns the appropriate error message corresponding to the error
  // number that we were passed.

    int count;
    
    for (count = 0; errorStringTable[count].string != NULL; count ++)
	if (errorStringTable[count].code == error)
	    return (errorStringTable[count].string);

    // Not found.  Don't change errno.
    return (NULL);
}