getpwuid()

Get information about the user with a given ID

Synopsis:

#include <sys/types.h>
#include <pwd.h>

struct passwd* getpwuid( uid_t uid );

Arguments:

uid: The userid whose entry you want to find.

Library:

libc

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

Description:

The getpwuid() function gets information about user uid. This function uses a static buffer that's overwritten by each call.

Note: The getpwent(), getpwnam(), and getpwuid() functions share the same static buffer.

Returns:

A pointer to an object of type struct passwd containing an entry from the group database with a matching uid, or NULL if an error occurred or the function couldn't find a matching entry.

Errors:

The getpwuid() function uses the following functions, and as a result, errno can be set to an error for any of these calls:

Examples:

/*
 * Print password info on the current user.
 */
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <pwd.h>

int main( void )
  {
    struct passwd* pw;

    if( ( pw = getpwuid( getuid() ) ) == NULL ) {
       fprintf( stderr,
          "getpwuid: no password entry\n" );
       return( EXIT_FAILURE );
    }
    printf( "login name  %s\n", pw->pw_name );
    printf( "user id     %d\n", pw->pw_uid );
    printf( "group id    %d\n", pw->pw_gid );
    printf( "home dir    %s\n", pw->pw_dir );
    printf( "login shell %s\n", pw->pw_shell );
    return( EXIT_SUCCESS );
  }

Classification:

POSIX 1003.1

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