GETCWD function __ Function

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Five, getcwd function

getcwd function

Header file

<unistd.h>

function form

Char *getcwd (char *buffer, size_t size)

return value

Success

Failed

Whether to set errno

Returns a pointer to the current working directory string

Null

Is

Description: The GETCWD function obtains the current working directory, saves the working directory in the caller-supplied string, and the size of the string is assigned by the user.

Error message:

(1): The einval:size parameter is zero or the buffer is a null pointer.

(2): The erange:size parameter is less than the length of the current working directory, and more memory needs to be allocated.

(3): eacces: Insufficient permissions, no read or search file name permissions.

Practical Walkthrough:

From the explanation of the GETCWD function, we must allocate enough space for the buffer to get the result that the user expects. You can define a string of length Path_max to hold the current path. Path_max is an optional constant in the POSIX standard. This means that the variable may or may not be defined in the limits.h.

#include <iostream>

#include <limits.h>

#include <unistd.h>

#ifndef Path_max

#define PATH_MAX 1024

#endif

int main (void)

{

Char Cur_work_dir[path_max] = {' I '};

std:: cout << "Current Max Path Length is <<"

<< Path_max << Std::endl;

if (GETCWD (Cur_work_dir, path_max) = = NULL)

{

Perror ("couldn ' t get current working directory!");

return (1);

}

Std::cout << "Current Working Directory is:" <<cur_work_dir << Std::endl;

return (0);

}