函数简介

程序示例

函数简介

函数原型：

int _chmod(

const char *filename,

int pmode

);

函数功能：改变文件的读写许可设置，如果改变成功返回0，否则返回-1

所属库：io.h

相关函数：_tchmod 、_wchmod

程序示例

#include <sys/types.h>

#include <sys/stat.h>

#include <io.h>

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

// Change the mode and report error or success

void set_mode_and_report(char * filename, int mask)

{

// Check for failure

if( _chmod( filename, mask ) == -1 )

{

// Determine cause of failure and report.

switch (errno)

{

case EINVAL:

fprintf( stderr, "Invalid parameter to chmod.\");

break;

case ENOENT:

fprintf( stderr, "File %s not found\", filename );

break;

default:

// Should never be reached

fprintf( stderr, "Unexpected error in chmod.\" );

}

}

else

{

if (mask == _S_IREAD)

printf( "Mode set to read-only\" );

else if (mask & _S_IWRITE)

printf( "Mode set to read/write\" );

}

fflush(stderr);

}

int main( void )

{

// Create or append to a file.

system( "echo /* End of file */ >> crt_chmod.c_input" );

// Set file mode to read-only:

set_mode_and_report("crt_chmod.c_input ", _S_IREAD );

system( "echo /* End of file */ >> crt_chmod.c_input " );

// Change back to read/write:

set_mode_and_report("crt_chmod.c_input ", _S_IWRITE );

system( "echo /* End of file */ >> crt_chmod.c_input " );

}