username.c

[詳解]

/*++
/* NAME
/*  username 3
/* SUMMARY
/*  lookup name of real user
/* SYNOPSIS
/*  #include <username.h>
/*
/*  const char *username()
/* DESCRIPTION
/*  username() jumps whatever system-specific hoops it takes to
/*  get the name of the user who started the process. The result
/*  is volatile. Make a copy if it is to be used for an appreciable
/*  amount of time.
/* LICENSE
/* .ad
/* .fi
/*  The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*--*/

/* System library. */

#include <sys_defs.h>
#include <unistd.h>
#include <pwd.h>

/* Utility library. */

#include "username.h"

/* username - get name of user */

const char *username(void)
{
    uid_t   uid;
    struct passwd *pwd;

    uid = getuid();
    if ((pwd = getpwuid(uid)) == 0)
    return (0);
    return (pwd->pw_name);
}