1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | PApp::SQL - absolutely easy yet fast and powerful sql access |
3 | PApp::SQL - absolutely easy yet fast and powerful sql access. |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use PApp::SQL; |
7 | use PApp::SQL; |
8 | |
8 | |
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13 | my $st = sql_insertid |
13 | my $st = sql_insertid |
14 | sql_exec "insert into ... values (?, ?)", $v1, $v2; |
14 | sql_exec "insert into ... values (?, ?)", $v1, $v2; |
15 | my $a = sql_fetch "select a from ..."; |
15 | my $a = sql_fetch "select a from ..."; |
16 | sql_fetch \my($a, $b), "select a,b ..."; |
16 | sql_fetch \my($a, $b), "select a,b ..."; |
17 | |
17 | |
18 | sql_exists "name from table where name like 'a%'" |
18 | sql_exists "table where name like 'a%'" |
19 | or die "a* required but not existent"; |
19 | or die "a* required but not existent"; |
20 | |
20 | |
21 | my $db = new PApp::SQL::Database "", "DBI:mysql:test", "user", "pass"; |
21 | my $db = new PApp::SQL::Database "", "DBI:mysql:test", "user", "pass"; |
22 | local $PApp::SQL::DBH = $db->checked_dbh; # does 'ping' |
22 | local $PApp::SQL::DBH = $db->checked_dbh; # does 'ping' |
23 | |
23 | |
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27 | |
27 | |
28 | This module provides you with easy-to-use functions to execute sql |
28 | This module provides you with easy-to-use functions to execute sql |
29 | commands (using DBI). Despite being easy to use, they are also quite |
29 | commands (using DBI). Despite being easy to use, they are also quite |
30 | efficient and allow you to write faster programs in less lines of code. It |
30 | efficient and allow you to write faster programs in less lines of code. It |
31 | should work with anything from perl-5.004_01 onwards, but I only support |
31 | should work with anything from perl-5.004_01 onwards, but I only support |
32 | 5.005+. |
32 | 5.005+. UTF8 handling (the C<sql_u*> family of functions) will only be |
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33 | effective with perl version 5.006 and beyond. |
33 | |
34 | |
34 | If the descriptions here seem terse or if you always wanted to know |
35 | If the descriptions here seem terse or if you always wanted to know |
35 | what PApp is then have a look at the PApp module which uses this module |
36 | what PApp is then have a look at the PApp module which uses this module |
36 | extensively but also provides you with a lot more gimmicks to play around |
37 | extensively but also provides you with a lot more gimmicks to play around |
37 | with to help you create cool applications ;) |
38 | with to help you create cool applications ;) |
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43 | use DBI (); |
44 | use DBI (); |
44 | |
45 | |
45 | BEGIN { |
46 | BEGIN { |
46 | use base qw(Exporter DynaLoader); |
47 | use base qw(Exporter DynaLoader); |
47 | |
48 | |
48 | $VERSION = 0.121; |
49 | $VERSION = 0.141; |
49 | @EXPORT = qw( |
50 | @EXPORT = qw( |
50 | sql_exec sql_fetch sql_fetchall sql_exists sql_insertid $sql_exec |
51 | sql_exec sql_fetch sql_fetchall sql_exists sql_insertid $sql_exec |
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52 | sql_uexec sql_ufetch sql_ufetchall sql_uexists |
51 | ); |
53 | ); |
52 | @EXPORT_OK = qw( |
54 | @EXPORT_OK = qw( |
53 | connect_cached |
55 | connect_cached |
54 | ); |
56 | ); |
55 | |
57 | |
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67 | =over 4 |
69 | =over 4 |
68 | |
70 | |
69 | =item $sql_exec |
71 | =item $sql_exec |
70 | |
72 | |
71 | Since the C<sql_exec> family of functions return a statement handle there |
73 | Since the C<sql_exec> family of functions return a statement handle there |
72 | must eb another way to test the return value of the C<execute> call. This |
74 | must be another way to test the return value of the C<execute> call. This |
73 | global variable contains the result of the most recent call to C<execute> |
75 | global variable contains the result of the most recent call to C<execute> |
74 | done by this module. |
76 | done by this module. |
75 | |
77 | |
76 | =item $PApp::SQL::DBH |
78 | =item $PApp::SQL::DBH |
77 | |
79 | |
78 | The default database handle used by this module if no C<$DBH> was |
80 | The default database handle used by this module if no C<$DBH> was |
79 | specified as argument and no C<$DBH> is found in the current package. See |
81 | specified as argument. See C<sql_exec> for a discussion. |
80 | C<sql_exec> for a discussion. |
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81 | |
82 | |
82 | =item $PApp::SQL::Database |
83 | =item $PApp::SQL::Database |
83 | |
84 | |
84 | The current default C<PApp::SQL::Database>-object. Future versions might |
85 | The current default C<PApp::SQL::Database>-object. Future versions might |
85 | automatically fall back on this database and create database handles from |
86 | automatically fall back on this database and create database handles from |
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109 | __LINE__ work fine as well). |
110 | __LINE__ work fine as well). |
110 | |
111 | |
111 | The reason C<$id> is necessary is that you might specify special connect |
112 | The reason C<$id> is necessary is that you might specify special connect |
112 | arguments or special flags, or you might want to configure your $DBH |
113 | arguments or special flags, or you might want to configure your $DBH |
113 | differently than maybe other applications requesting the same database |
114 | differently than maybe other applications requesting the same database |
114 | connection. If none of this is becessary for your application you can |
115 | connection. If none of this is necessary for your application you can |
115 | leave $id empty (i.e. ""). |
116 | leave C<$id> empty (i.e. ""). |
116 | |
117 | |
117 | If specified, C<$connect> is a callback (e.g. a coderef) that will be |
118 | If specified, C<$connect> is a callback (e.g. a coderef) that will be |
118 | called each time a new connection is being established, with the new |
119 | called each time a new connection is being established, with the new |
119 | C<$dbh> as first argument. |
120 | C<$dbh> as first argument. |
120 | |
121 | |
121 | Examples: |
122 | Examples: |
122 | |
123 | |
123 | # try your luck opening the papp database without access info |
124 | # try your luck opening the papp database without access info |
124 | $dbh = connect_cached __FILE__, "DBI:mysql:papp"; |
125 | $dbh = connect_cached __FILE__, "DBI:mysql:papp"; |
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126 | |
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127 | Mysql-specific behaviour: The default setting of |
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128 | C<mysql_client_found_rows> is TRUE, you can overwrite this, though. |
125 | |
129 | |
126 | =cut |
130 | =cut |
127 | |
131 | |
128 | sub connect_cached { |
132 | sub connect_cached { |
129 | my ($id, $dsn, $user, $pass, $flags, $connect) = @_; |
133 | my ($id, $dsn, $user, $pass, $flags, $connect) = @_; |
130 | # the following line is duplicated in PApp::SQL::Database::new |
134 | # the following line is duplicated in PApp::SQL::Database::new |
131 | $id = "$id\0$dsn\0$user\0$pass"; |
135 | $id = "$id\0$dsn\0$user\0$pass"; |
132 | unless ($dbcache{$id} && $dbcache{$id}->ping) { |
136 | unless ($dbcache{$id} && $dbcache{$id}->ping) { |
133 | #warn "connecting to ($dsn|$user|$pass|$flags)\n";#d# |
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134 | # first, nuke our statement cache (sooory ;) |
137 | # first, nuke our statement cache (sooory ;) |
135 | cachesize cachesize 0; |
138 | cachesize cachesize 0; |
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139 | |
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140 | # then make mysql behave more standardly by default |
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141 | $dsn =~ /^[Dd][Bb][Ii]:mysql:/ |
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142 | and $dsn !~ /;mysql_client_found_rows/ |
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143 | and $dsn .= ";mysql_client_found_rows=1"; |
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144 | |
136 | # then connect anew |
145 | # then connect anew |
137 | $dbcache{$id} = |
146 | $dbcache{$id} = |
138 | eval { DBI->connect($dsn, $user, $pass, $flags) } |
147 | eval { DBI->connect($dsn, $user, $pass, $flags) } |
139 | || eval { DBI->connect($dsn, $user, $pass, $flags) } |
148 | || eval { DBI->connect($dsn, $user, $pass, $flags) } |
140 | || die "unable to connect to database $dsn: $DBI::errstr\n"; |
149 | || die "unable to connect to database $dsn: $DBI::errstr\n"; |
… | |
… | |
143 | $dbcache{$id}; |
152 | $dbcache{$id}; |
144 | } |
153 | } |
145 | |
154 | |
146 | =item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...] |
155 | =item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...] |
147 | |
156 | |
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157 | =item $sth = sql_uexec <see sql_exec> |
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158 | |
148 | C<sql_exec> is the most important and most-used function in this module. |
159 | C<sql_exec> is the most important and most-used function in this module. |
149 | |
160 | |
150 | Runs the given sql command with the given parameters and returns the |
161 | Runs the given sql command with the given parameters and returns the |
151 | statement handle. The command and the statement handle will be cached |
162 | statement handle. The command and the statement handle will be cached |
152 | (with the database handle and the sql string as key), so prepare will be |
163 | (with the database handle and the sql string as key), so prepare will be |
153 | called only once for each distinct sql call (please keep in mind that the |
164 | called only once for each distinct sql call (please keep in mind that the |
154 | returned statement will always be the same, so, if you call C<sql_exec> |
165 | returned statement will always be the same, so, if you call C<sql_exec> |
155 | with the same dbh and sql-statement twice (e.g. in a subroutine you |
166 | with the same dbh and sql-statement twice (e.g. in a subroutine you |
156 | called), the statement handle for the first call mustn't be used. |
167 | called), the statement handle for the first call mustn't not be in use |
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168 | anymore, as the subsequent call will re-use the handle. |
157 | |
169 | |
158 | The database handle (the first argument) is optional. If it is missing, |
170 | The database handle (the first argument) is optional. If it is missing, |
159 | C<sql_exec> first tries to use the variable C<$DBH> in the current (= |
171 | it tries to use database handle in C<$PApp::SQL::DBH>, which you can set |
160 | calling) package and, if that fails, it tries to use database handle in |
172 | before calling these functions. NOTICE: future and former versions of |
161 | C<$PApp::SQL::DBH>, which you can set before calling these functions. |
173 | PApp::SQL might also look up the global variable C<$DBH> in the callers |
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174 | package. |
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175 | |
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176 | =begin comment |
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177 | |
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178 | If it is missing, C<sql_exec> first tries to use the variable C<$DBH> |
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179 | in the current (= calling) package and, if that fails, it tries to use |
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180 | database handle in C<$PApp::SQL::DBH>, which you can set before calling |
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181 | these functions. |
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182 | |
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183 | =end comment |
162 | |
184 | |
163 | The actual return value from the C<$sth->execute> call is stored in the |
185 | The actual return value from the C<$sth->execute> call is stored in the |
164 | package-global (and exported) variable C<$sql_exec>. |
186 | package-global (and exported) variable C<$sql_exec>. |
165 | |
187 | |
166 | If any error occurs C<sql_exec> will throw an exception. |
188 | If any error occurs C<sql_exec> will throw an exception. |
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189 | |
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190 | C<sql_uexec> is similar to C<sql_exec> but upgrades all input arguments to |
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191 | utf8 before calling the C<execute> method. |
167 | |
192 | |
168 | Examples: |
193 | Examples: |
169 | |
194 | |
170 | # easy one |
195 | # easy one |
171 | my $st = sql_exec "select name, id from table where id = ?", $id; |
196 | my $st = sql_exec "select name, id from table where id = ?", $id; |
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181 | sql_exec $dbh, "update file set name = ?", "oops.txt"; |
206 | sql_exec $dbh, "update file set name = ?", "oops.txt"; |
182 | |
207 | |
183 | |
208 | |
184 | =item sql_fetch <see sql_exec> |
209 | =item sql_fetch <see sql_exec> |
185 | |
210 | |
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211 | =item sql_ufetch <see sql_uexec> |
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212 | |
186 | Execute a sql-statement and fetch the first row of results. Depending on |
213 | Execute an sql-statement and fetch the first row of results. Depending on |
187 | the caller context the row will be returned as a list (array context), or |
214 | the caller context the row will be returned as a list (array context), or |
188 | just the first columns. In table form: |
215 | just the first columns. In table form: |
189 | |
216 | |
190 | CONTEXT RESULT |
217 | CONTEXT RESULT |
191 | void () |
218 | void () |
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202 | |
229 | |
203 | my($name, $amount) = sql_fetch "select ...", args... |
230 | my($name, $amount) = sql_fetch "select ...", args... |
204 | |
231 | |
205 | ... and it's still quite fast unless you fetch large amounts of data. |
232 | ... and it's still quite fast unless you fetch large amounts of data. |
206 | |
233 | |
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234 | C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to |
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235 | utf8 and forces all result values to utf8 (this does I<not> include result |
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236 | parameters, only return values. Using bind variables in cinjunction with |
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237 | sql_u* functions results in undefined behaviour). |
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238 | |
207 | =item sql_fetchall <see sql_exec> |
239 | =item sql_fetchall <see sql_exec> |
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240 | |
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241 | =item sql_ufetchall <see sql_uexec> |
208 | |
242 | |
209 | Similarly to C<sql_fetch>, but all result rows will be fetched (this is |
243 | Similarly to C<sql_fetch>, but all result rows will be fetched (this is |
210 | of course inefficient for large results!). The context is ignored (only |
244 | of course inefficient for large results!). The context is ignored (only |
211 | list context makes sense), but the result still depends on the number of |
245 | list context makes sense), but the result still depends on the number of |
212 | columns in the result: |
246 | columns in the result: |
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224 | |
258 | |
225 | for (sql_fetchall "select name, age, place from user") { |
259 | for (sql_fetchall "select name, age, place from user") { |
226 | my ($name, $age, $place) = @$_; |
260 | my ($name, $age, $place) = @$_; |
227 | } |
261 | } |
228 | |
262 | |
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263 | C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input |
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264 | values to utf8 and forces all result values to utf8 (see the caveats in |
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265 | the description of C<sql_ufetch>, though). |
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266 | |
229 | =item sql_exists "<table> where ...", args... |
267 | =item sql_exists "<table_references> where <where_condition>...", args... |
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268 | |
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269 | =item sql_uexists <see sql_exists> |
230 | |
270 | |
231 | Check wether the result of the sql-statement "select xxx from |
271 | Check wether the result of the sql-statement "select xxx from |
232 | $first_argument" would be empty or not (that is, imagine the string |
272 | $first_argument" would be empty or not (that is, imagine the string |
233 | "select from" were prepended to your statement (it isn't)). Should work |
273 | "select * from" were prepended to your statement (it isn't)). Should work |
234 | with every database but can be quite slow, except on mysql, where this |
274 | with every database but can be quite slow, except on mysql, where this |
235 | should be quite fast. |
275 | should be quite fast. |
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276 | |
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277 | C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to |
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278 | utf8. |
236 | |
279 | |
237 | Examples: |
280 | Examples: |
238 | |
281 | |
239 | print "user 7 exists!\n" |
282 | print "user 7 exists!\n" |
240 | if sql_exists "user where id = ?", 7; |
283 | if sql_exists "user where id = ?", 7; |
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275 | |
318 | |
276 | =item [old-size] = cachesize [new-size] |
319 | =item [old-size] = cachesize [new-size] |
277 | |
320 | |
278 | Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The |
321 | Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The |
279 | default is somewhere around 50 (= the 50 last recently used statements |
322 | default is somewhere around 50 (= the 50 last recently used statements |
280 | will be cached). It shouldn't be too large, since a simple linear listed |
323 | will be cached). It shouldn't be too large, since a simple linear list |
281 | is used for the cache at the moment (which, for small (<100) cache sizes |
324 | is used for the cache at the moment (which, for small (<100) cache sizes |
282 | is actually quite fast). |
325 | is actually quite fast). |
283 | |
326 | |
284 | The function always returns the cache size in effect I<before> the call, |
327 | The function always returns the cache size in effect I<before> the call, |
285 | so, to nuke the cache (for example, when a database connection has died |
328 | so, to nuke the cache (for example, when a database connection has died |
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314 | |
357 | |
315 | package PApp::SQL::Database; |
358 | package PApp::SQL::Database; |
316 | |
359 | |
317 | =head2 THE DATABASE CLASS |
360 | =head2 THE DATABASE CLASS |
318 | |
361 | |
319 | Again (sigh) the problem of persistency. What do you do when you have to serialize on object |
362 | Again (sigh) the problem of persistency. What do you do when you have |
320 | that contains (or should contain) a database handle? Short answer: you don't. Long answer: |
363 | to serialize on object that contains (or should contain) a database |
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364 | handle? Short answer: you don't. Long answer: you can embed the necessary |
321 | you can embed the necessary information to recreate the dbh when needed. |
365 | information to recreate the dbh when needed. |
322 | |
366 | |
323 | The C<PApp::SQL::Database> class does that, in a relatively efficient |
367 | The C<PApp::SQL::Database> class does that, in a relatively efficient |
324 | fashion: the overhead is currently a single method call per access (you |
368 | fashion: the overhead is currently a single method call per access (you |
325 | can cache the real dbh if you want). |
369 | can cache the real dbh if you want). |
326 | |
370 | |
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366 | |
410 | |
367 | =item $db->dsn |
411 | =item $db->dsn |
368 | |
412 | |
369 | Return the DSN (L<DBI>) fo the database object (e.g. for error messages). |
413 | Return the DSN (L<DBI>) fo the database object (e.g. for error messages). |
370 | |
414 | |
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415 | =item $db->login |
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416 | |
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417 | Return the login name. |
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418 | |
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419 | =item $db->password |
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420 | |
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421 | Return the password (emphasizing the fact that the password is stored plaintext ;) |
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422 | |
371 | =cut |
423 | =cut |
372 | |
424 | |
373 | sub dsn($) { |
425 | sub dsn($) { |
374 | my $self = shift; |
426 | my $self = shift; |
375 | (split /\x00/, $self->[0])[1]; |
427 | (split /\x00/, $self->[0])[1]; |
376 | } |
428 | } |
377 | |
429 | |
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430 | sub login($) { |
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431 | my $self = shift; |
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432 | (split /\x00/, $self->[0])[2]; |
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433 | } |
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434 | |
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435 | sub password($) { |
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436 | my $self = shift; |
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437 | (split /\x00/, $self->[0])[3]; |
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438 | } |
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439 | |
378 | =back |
440 | =back |
379 | |
441 | |
380 | =cut |
442 | =cut |
381 | |
443 | |
382 | 1; |
444 | 1; |