getcwd()

Get the name of the current working directory

Synopsis:

#include <unistd.h>

char* getcwd( char* buffer, 
              size_t size );

Arguments:

buffer: NULL, or a pointer to a buffer where the function can store the directory name.
size: The size of the buffer, in bytes.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The getcwd() function returns the name of the current working directory. buffer is a pointer to a buffer of at least size bytes where the NUL-terminated name of the current working directory will be placed.

The maximum size that might be required for buffer is PATH_MAX + 1 bytes. See <limits.h>.

Note: POSIX doesn't specify what should happen if you call getcwd( NULL, 0). The QNX Neutrino version (like many others) allocates a buffer for the name of the directory; it's up to your application to free the buffer when you no longer need it.

Returns:

The address of the string containing the name of the current working directory, or NULL if an error occurred (errno is set).

Errors:

EINVAL: The argument size is negative or 0.
ELOOP: Too many levels of symbolic links.
ENOSYS: The getcwd() function isn't implemented for the filesystem specified in the current working directory.
ERANGE: The buffer is too small (as specified by size) to contain the name of the current working directory.

Examples:

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>

int main( void )
{
    char* cwd;
    char buff[PATH_MAX + 1];

    cwd = getcwd( buff, PATH_MAX + 1 );
    if( cwd != NULL ) {
        printf( "My working directory is %s.\n", cwd );
    }

    return EXIT_SUCCESS;
}

produces the output:

My working directory is /home/bill.

Classification:

POSIX 1003.1

Safety:
Cancellation point	Yes
Interrupt handler	No
Signal handler	No
Thread	Yes

Caveats:

There is only one current working directory per process. In a multithreaded application, any thread calling chdir() will change the current working directory for all threads in that process.