diff options
| -rw-r--r-- | lib/User/pwent.pm | 285 |
1 files changed, 239 insertions, 46 deletions
diff --git a/lib/User/pwent.pm b/lib/User/pwent.pm index 39bfea4fe0..31cf74227c 100644 --- a/lib/User/pwent.pm +++ b/lib/User/pwent.pm @@ -1,51 +1,179 @@ package User::pwent; + +use 5.006; + use strict; +use warnings; + +use Config; +use Carp; -use 5.005_64; our(@EXPORT, @EXPORT_OK, %EXPORT_TAGS); -BEGIN { +BEGIN { use Exporter (); @EXPORT = qw(getpwent getpwuid getpwnam getpw); @EXPORT_OK = qw( - $pw_name $pw_passwd $pw_uid - $pw_gid $pw_quota $pw_comment - $pw_gecos $pw_dir $pw_shell - ); - %EXPORT_TAGS = ( FIELDS => [ @EXPORT_OK, @EXPORT ] ); + pw_has + + $pw_name $pw_passwd $pw_uid $pw_gid + $pw_gecos $pw_dir $pw_shell + $pw_expire $pw_change $pw_class + $pw_age + $pw_quota $pw_comment + $pw_expire + + ); + %EXPORT_TAGS = ( + FIELDS => [ grep(/^\$pw_/, @EXPORT_OK), @EXPORT ], + ALL => [ @EXPORT, @EXPORT_OK ], + ); } -use vars @EXPORT_OK; +use vars grep /^\$pw_/, @EXPORT_OK; + +# +# XXX: these mean somebody hacked this module's source +# without understanding the underlying assumptions. +# +my $IE = "[INTERNAL ERROR]"; # Class::Struct forbids use of @ISA sub import { goto &Exporter::import } use Class::Struct qw(struct); struct 'User::pwent' => [ - name => '$', - passwd => '$', - uid => '$', - gid => '$', - quota => '$', - comment => '$', - gecos => '$', - dir => '$', - shell => '$', + name => '$', # pwent[0] + passwd => '$', # pwent[1] + uid => '$', # pwent[2] + gid => '$', # pwent[3] + + # you'll only have one/none of these three + change => '$', # pwent[4] + age => '$', # pwent[4] + quota => '$', # pwent[4] + + # you'll only have one/none of these two + comment => '$', # pwent[5] + class => '$', # pwent[5] + + # you might not have this one + gecos => '$', # pwent[6] + + dir => '$', # pwent[7] + shell => '$', # pwent[8] + + # you might not have this one + expire => '$', # pwent[9] + ]; -sub populate (@) { + +# init our groks hash to be true if the built platform knew how +# to do each struct pwd field that perl can ever under any circumstances +# know about. we do not use /^pw_?/, but just the tails. +sub _feature_init { + our %Groks; # whether build system knew how to do this feature + for my $feep ( qw{ + pwage pwchange pwclass pwcomment + pwexpire pwgecos pwpasswd pwquota + } + ) + { + my $short = $feep =~ /^pw(.*)/ + ? $1 + : do { + # not cluck, as we know we called ourselves, + # and a confession is probably imminent anyway + warn("$IE $feep is a funny struct pwd field"); + $feep; + }; + + exists $Config{ "d_" . $feep } + || confess("$IE Configure doesn't d_$feep"); + $Groks{$short} = defined $Config{ "d_" . $feep }; + } + # assume that any that are left are always there + for my $feep (grep /^\$pw_/s, @EXPORT_OK) { + $feep =~ /^\$pw_(.*)/; + $Groks{$1} = 1 unless defined $Groks{$1}; + } +} + +# With arguments, reports whether one or more fields are all implemented +# in the build machine's struct pwd pw_*. May be whitespace separated. +# We do not use /^pw_?/, just the tails. +# +# Without arguments, returns the list of fields implemented on build +# machine, space separated in scalar context. +# +# Takes exception to being asked whether this machine's struct pwd has +# a field that Perl never knows how to provide under any circumstances. +# If the module does this idiocy to itself, the explosion is noisier. +# +sub pw_has { + our %Groks; # whether build system knew how to do this feature + my $cando = 1; + my $sploder = caller() ne __PACKAGE__ + ? \&croak + : sub { confess("$IE @_") }; + if (@_ == 0) { + my @valid = sort grep { $Groks{$_} } keys %Groks; + return wantarray ? @valid : "@valid"; + } + for my $feep (map { split } @_) { + defined $Groks{$feep} + || $sploder->("$feep is never a valid struct pwd field"); + $cando &&= $Groks{$feep}; + } + return $cando; +} + +sub _populate (@) { return unless @_; my $pwob = new(); - ( $pw_name, $pw_passwd, $pw_uid, - $pw_gid, $pw_quota, $pw_comment, - $pw_gecos, $pw_dir, $pw_shell, ) = @$pwob = @_; + # Any that haven't been pw_had are assumed on "all" platforms of + # course, this may not be so, but you can't get here otherwise, + # since the underlying core call already took exception to your + # impudence. + + $pw_name = $pwob->name ( $_[0] ); + $pw_passwd = $pwob->passwd ( $_[1] ) if pw_has("passwd"); + $pw_uid = $pwob->uid ( $_[2] ); + $pw_gid = $pwob->gid ( $_[3] ); + + if (pw_has("change")) { + $pw_change = $pwob->change ( $_[4] ); + } + elsif (pw_has("age")) { + $pw_age = $pwob->age ( $_[4] ); + } + elsif (pw_has("quota")) { + $pw_quota = $pwob->quota ( $_[4] ); + } + + if (pw_has("class")) { + $pw_class = $pwob->class ( $_[5] ); + } + elsif (pw_has("comment")) { + $pw_comment = $pwob->comment( $_[5] ); + } + + $pw_gecos = $pwob->gecos ( $_[6] ) if pw_has("gecos"); + + $pw_dir = $pwob->dir ( $_[7] ); + $pw_shell = $pwob->shell ( $_[8] ); + + $pw_expire = $pwob->expire ( $_[9] ) if pw_has("expire"); return $pwob; -} +} -sub getpwent ( ) { populate(CORE::getpwent()) } -sub getpwnam ($) { populate(CORE::getpwnam(shift)) } -sub getpwuid ($) { populate(CORE::getpwuid(shift)) } -sub getpw ($) { ($_[0] =~ /^\d+/) ? &getpwuid : &getpwnam } +sub getpwent ( ) { _populate(CORE::getpwent()) } +sub getpwnam ($) { _populate(CORE::getpwnam(shift)) } +sub getpwuid ($) { _populate(CORE::getpwuid(shift)) } +sub getpw ($) { ($_[0] =~ /^\d+\z/s) ? &getpwuid : &getpwnam } + +_feature_init(); 1; __END__ @@ -57,42 +185,95 @@ User::pwent - by-name interface to Perl's built-in getpw*() functions =head1 SYNOPSIS use User::pwent; - $pw = getpwnam('daemon') or die "No daemon user"; - if ( $pw->uid == 1 && $pw->dir =~ m#^/(bin|tmp)?$# ) { + $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') or die "No daemon user"; - if ( $pw_uid == 1 && $pw_dir =~ m#^/(bin|tmp)?$# ) { + 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: ", pw_has(), "\n"; + =head1 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 F<pwd.h>; -namely name, passwd, uid, gid, quota, comment, gecos, dir, and shell. +C<User::pwent> objects. This object has methods that return the +similarly named structure field name from the C's passwd structure +from F<pwd.h>, stripped of their leading "pw_" parts, namely C<name>, +C<passwd>, C<uid>, C<gid>, C<change>, C<age>, C<quota>, C<comment>, +C<class>, C<gecos>, C<dir>, C<shell>, and C<expire>. The C<passwd>, +C<gecos>, and C<shell> fields should be considered tainted. -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 C<pw_> in front their method names. -Thus, C<$passwd_obj-E<gt>shell()> corresponds to $pw_shell if you import -the fields. +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 C<pw_> in front their method +names. Thus, C<< $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 C<use> an empty import list, and then access -function functions with their full qualified names. -On the other hand, the built-ins are still available -via the C<CORE::> pseudo-package. +To access this functionality without the core overrides, pass the +C<use> an empty import list, and then access function functions +with their full qualified names. The built-ins are always still +available via the C<CORE::> pseudo-package. + +=head2 System Specifics + +Perl believes that no machine ever has more than one of C<change>, +C<age>, or C<quota> implemented, nor more than one of either +C<comment> or C<class>. Some machines do not support C<expire>, +C<gecos>, or allegedly, C<passwd>. You may call these methods +no matter what machine you're on, but they return C<undef> if +unimplemented. + +You may ask whether one of these was implemented on the system Perl +was built on by asking the importable C<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 +and 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 C<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 C<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 C<&> in the gecos field should be replaced by the user's properly +capitalized login C<name>. The C<shell> field, if blank, must be +assumed to be F</bin/sh>. Perl does not do this for you. The +C<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. =head1 NOTE @@ -102,3 +283,15 @@ module to build a struct-like class, you shouldn't rely upon this. =head1 AUTHOR Tom Christiansen + +=head1 HISTORY + +=over + +=item March 18th, 2000 + +Reworked internals to support better interface to dodgey fields +than normal Perl function provides. Added pw_has() field. Improved +documentation. + +=back |