User::pwent - man - phpMan

NAME
    User::pwent - by-name interface to Perl's built-in getpw*() functions

SYNOPSIS
     use User::pwent;
     $pw = getpwnam('daemon')       || die "No daemon user";
     if ( $pw->uid == 1 && $pw->dir =~ m#^/(bin|tmp)?\z#s ) {
         print "gid 1 on root dir";
     }

     $real_shell = $pw->shell || '/bin/sh';

     for (($fullname, $office, $workphone, $homephone) =
            split /\s*,\s*/, $pw->gecos)
     {
        s/&/ucfirst(lc($pw->name))/ge;
     }

     use User::pwent qw(:FIELDS);
     getpwnam('daemon')             || die "No daemon user";
     if ( $pw_uid == 1 && $pw_dir =~ m#^/(bin|tmp)?\z#s ) {
         print "gid 1 on root dir";
     }

     $pw = getpw($whoever);

     use User::pwent qw/:DEFAULT pw_has/;
     if (pw_has(qw[gecos expire quota])) { .... }
     if (pw_has("name uid gid passwd"))  { .... }
     print "Your struct pwd has: ", scalar pw_has(), "\n";

DESCRIPTION
    This module's default exports override the core getpwent(), getpwuid(),
    and getpwnam() functions, replacing them with versions that return
    "User::pwent" objects. This object has methods that return the similarly
    named structure field name from the C's passwd structure from pwd.h,
    stripped of their leading "pw_" parts, namely "name", "passwd", "uid",
    "gid", "change", "age", "quota", "comment", "class", "gecos", "dir",
    "shell", and "expire". The "passwd", "gecos", and "shell" fields are
    tainted when running in taint mode.

    You may also import all the structure fields directly into your
    namespace as regular variables using the :FIELDS import tag. (Note that
    this still overrides your core functions.) Access these fields as
    variables named with a preceding "pw_" in front their method names.
    Thus, "$passwd_obj->shell" corresponds to $pw_shell if you import the
    fields.

    The getpw() function is a simple front-end that forwards a numeric
    argument to getpwuid() and the rest to getpwnam().

    To access this functionality without the core overrides, pass the "use"
    an empty import list, and then access function functions with their full
    qualified names. The built-ins are always still available via the
    "CORE::" pseudo-package.

  System Specifics
    Perl believes that no machine ever has more than one of "change", "age",
    or "quota" implemented, nor more than one of either "comment" or
    "class". Some machines do not support "expire", "gecos", or allegedly,
    "passwd". You may call these methods no matter what machine you're on,
    but they return "undef" if unimplemented.

    You may ask whether one of these was implemented on the system Perl was
    built on by asking the importable "pw_has" function about them. This
    function returns true if all parameters are supported fields on the
    build platform, false if one or more were not, and raises an exception
    if you asked about a field that Perl never knows how to provide.
    Parameters may be in a space-separated string, or as separate arguments.
    If you pass no parameters, the function returns the list of "struct pwd"
    fields supported by your build platform's C library, as a list in list
    context, or a space-separated string in scalar context. Note that just
    because your C library had a field doesn't necessarily mean that it's
    fully implemented on that system.

    Interpretation of the "gecos" field varies between systems, but
    traditionally holds 4 comma-separated fields containing the user's full
    name, office location, work phone number, and home phone number. An "&"
    in the gecos field should be replaced by the user's properly capitalized
    login "name". The "shell" field, if blank, must be assumed to be
    /bin/sh. Perl does not do this for you. The "passwd" is one-way hashed
    garble, not clear text, and may not be unhashed save by brute-force
    guessing. Secure systems use more a more secure hashing than DES. On
    systems supporting shadow password systems, Perl automatically returns
    the shadow password entry when called by a suitably empowered user, even
    if your underlying vendor-provided C library was too short-sighted to
    realize it should do this.

    See passwd(5) and getpwent(3) for details.

NOTE
    While this class is currently implemented using the Class::Struct module
    to build a struct-like class, you shouldn't rely upon this.

AUTHOR
    Tom Christiansen

HISTORY
    March 18th, 2000
        Reworked internals to support better interface to dodgey fields than
        normal Perl function provides. Added pw_has() field. Improved
        documentation.