| Server IP : 103.119.228.120 / Your IP : 3.145.108.43 Web Server : Apache System : Linux v8.techscape8.com 3.10.0-1160.119.1.el7.tuxcare.els2.x86_64 #1 SMP Mon Jul 15 12:09:18 UTC 2024 x86_64 User : nobody ( 99) PHP Version : 5.6.40 Disable Function : shell_exec,symlink,system,exec,proc_get_status,proc_nice,proc_terminate,define_syslog_variables,syslog,openlog,closelog,escapeshellcmd,passthru,ocinum cols,ini_alter,leak,listen,chgrp,apache_note,apache_setenv,debugger_on,debugger_off,ftp_exec,dl,dll,myshellexec,proc_open,socket_bind,proc_close,escapeshellarg,parse_ini_filepopen,fpassthru,exec,passthru,escapeshellarg,escapeshellcmd,proc_close,proc_open,ini_alter,popen,show_source,proc_nice,proc_terminate,proc_get_status,proc_close,pfsockopen,leak,apache_child_terminate,posix_kill,posix_mkfifo,posix_setpgid,posix_setsid,posix_setuid,dl,symlink,shell_exec,system,dl,passthru,escapeshellarg,escapeshellcmd,myshellexec,c99_buff_prepare,c99_sess_put,fpassthru,getdisfunc,fx29exec,fx29exec2,is_windows,disp_freespace,fx29sh_getupdate,fx29_buff_prepare,fx29_sess_put,fx29shexit,fx29fsearch,fx29ftpbrutecheck,fx29sh_tools,fx29sh_about,milw0rm,imagez,sh_name,myshellexec,checkproxyhost,dosyayicek,c99_buff_prepare,c99_sess_put,c99getsource,c99sh_getupdate,c99fsearch,c99shexit,view_perms,posix_getpwuid,posix_getgrgid,posix_kill,parse_perms,parsesort,view_perms_color,set_encoder_input,ls_setcheckboxall,ls_reverse_all,rsg_read,rsg_glob,selfURL,dispsecinfo,unix2DosTime,addFile,system,get_users,view_size,DirFiles,DirFilesWide,DirPrintHTMLHeaders,GetFilesTotal,GetTitles,GetTimeTotal,GetMatchesCount,GetFileMatchesCount,GetResultFiles,fs_copy_dir,fs_copy_obj,fs_move_dir,fs_move_obj,fs_rmdir,SearchText,getmicrotime MySQL : ON | cURL : ON | WGET : ON | Perl : ON | Python : ON | Sudo : ON | Pkexec : ON Directory : /usr/share/doc/postgresql-9.2.24/html/ |
Upload File : |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>Modules and the unknown Command</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.2.24 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="PL/Tcl - Tcl Procedural Language"
HREF="pltcl.html"><LINK
REL="PREVIOUS"
TITLE="Trigger Procedures in PL/Tcl"
HREF="pltcl-trigger.html"><LINK
REL="NEXT"
TITLE="Tcl Procedure Names"
HREF="pltcl-procnames.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2017-11-06T22:43:11"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.2.24 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="Trigger Procedures in PL/Tcl"
HREF="pltcl-trigger.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="pltcl.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
>Chapter 40. PL/Tcl - Tcl Procedural Language</TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="Tcl Procedure Names"
HREF="pltcl-procnames.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="PLTCL-UNKNOWN"
>40.7. Modules and the <CODE
CLASS="FUNCTION"
>unknown</CODE
> Command</A
></H1
><P
> PL/Tcl has support for autoloading Tcl code when used.
It recognizes a special table, <TT
CLASS="LITERAL"
>pltcl_modules</TT
>, which
is presumed to contain modules of Tcl code. If this table
exists, the module <TT
CLASS="LITERAL"
>unknown</TT
> is fetched from the table
and loaded into the Tcl interpreter immediately before the first
execution of a PL/Tcl function in a database session. (This
happens separately for each Tcl interpreter, if more than one is
used in a session; see <A
HREF="pltcl-global.html"
>Section 40.4</A
>.)
</P
><P
> While the <TT
CLASS="LITERAL"
>unknown</TT
> module could actually contain any
initialization script you need, it normally defines a Tcl
<CODE
CLASS="FUNCTION"
>unknown</CODE
> procedure that is invoked whenever Tcl does
not recognize an invoked procedure name. <SPAN
CLASS="APPLICATION"
>PL/Tcl</SPAN
>'s standard version
of this procedure tries to find a module in <TT
CLASS="LITERAL"
>pltcl_modules</TT
>
that will define the required procedure. If one is found, it is
loaded into the interpreter, and then execution is allowed to
proceed with the originally attempted procedure call. A
secondary table <TT
CLASS="LITERAL"
>pltcl_modfuncs</TT
> provides an index of
which functions are defined by which modules, so that the lookup
is reasonably quick.
</P
><P
> The <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> distribution includes
support scripts to maintain these tables:
<TT
CLASS="COMMAND"
>pltcl_loadmod</TT
>, <TT
CLASS="COMMAND"
>pltcl_listmod</TT
>,
<TT
CLASS="COMMAND"
>pltcl_delmod</TT
>, as well as source for the standard
<TT
CLASS="LITERAL"
>unknown</TT
> module in <TT
CLASS="FILENAME"
>share/unknown.pltcl</TT
>. This module
must be loaded
into each database initially to support the autoloading mechanism.
</P
><P
> The tables <TT
CLASS="LITERAL"
>pltcl_modules</TT
> and <TT
CLASS="LITERAL"
>pltcl_modfuncs</TT
>
must be readable by all, but it is wise to make them owned and
writable only by the database administrator. As a security
precaution, PL/Tcl will ignore <TT
CLASS="LITERAL"
>pltcl_modules</TT
> (and thus,
not attempt to load the <TT
CLASS="LITERAL"
>unknown</TT
> module) unless it is
owned by a superuser. But update privileges on this table can be
granted to other users, if you trust them sufficiently.
</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="pltcl-trigger.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="pltcl-procnames.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Trigger Procedures in PL/Tcl</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="pltcl.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Tcl Procedure Names</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>