libcgi_session.3

c语言cgi库,可以实现用C语言实现CGI脚本

.TH "Session Handling" 3 "13 Mar 2003" "LibCGI" \" -*- nroff -*-
.ad l
.nh
.SH NAME
Session Handling \- 
.SH "Detailed Description"
.PP 
One of the most diferencials of LibCGI is its support to sessions, a mechanism that permits the application to keep variables trough the user's session, when he is visiting your website.
.SS "Functions"

.in +1c
.ti -1c
.RI "int \fBcgi_session_destroy\fP ()"
.br
.RI "\fIDestroys the session.\fP"
.ti -1c
.RI "char * \fBcgi_session_var\fP (const char *var_name)"
.br
.RI "\fIGets session variable's value.\fP"
.ti -1c
.RI "void \fBcgi_session_cookie_name\fP (const char *cookie_name)"
.br
.RI "\fIDefines the name of the cookie that LibCGI will use to store session's ID.\fP"
.ti -1c
.RI "void \fBcgi_session_save_path\fP (const char *path)"
.br
.RI "\fIDefines where session control files will be saved.\fP"
.ti -1c
.RI "int \fBcgi_session_register_var\fP (const char *name, const char *value)"
.br
.RI "\fIRegister a variable in the current opened session.\fP"
.ti -1c
.RI "int \fBcgi_session_alter_var\fP (const char *name, const char *new_value)"
.br
.RI "\fIAlter session variable value.\fP"
.ti -1c
.RI "int \fBcgi_session_var_exists\fP (const char *name)"
.br
.RI "\fISearches for determined session variable.\fP"
.ti -1c
.RI "int \fBcgi_session_unregister_var\fP (char *name)"
.br
.RI "\fIUnregister some session variable.\fP"
.ti -1c
.RI "int \fBcgi_session_start\fP ()"
.br
.RI "\fIStarts a new session.\fP"
.in -1c
.SH "Function Documentation"
.PP 
.SS "int cgi_session_alter_var (const char * name, const char * new_value)"
.PP
Alter session variable value.Change session variable 'name' value to data pointer by 'new_value' 
.PP
\fBParameters:\fP
.RS 4
\fIname\fP Session variable name to change 
.br
\fInew_value\fP New session variable value 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBcgi_session_register_var()\fP, \fBcgi_session_unregister_var()\fP 
.RE
.PP

.SS "void cgi_session_cookie_name (const char * cookie_name)"
.PP
Defines the name of the cookie that LibCGI will use to store session's ID.This function works like \fBcgi_session_save_path()\fP. This functionality let you to use different names for each site, but remember, you cannot use multiple session for the same application yet.
.PP
\fBParameters:\fP
.RS 4
\fIcookie_name\fP Name of the cookie to create 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBcgi_session_save_path()\fP 
.RE
.PP
\fBNote:\fP
.RS 4
This function must be called before \fBcgi_session_start()\fP 
.RE
.PP

.SS "int cgi_session_destroy ()"
.PP
Destroys the session.Destroys the current opened session, including all data. After session_destroy() was called, is not more possible to use session functions before an another call to session_start() 
.PP
\fBReturns:\fP
.RS 4
1 if no errors, 0 if. 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBcgi_session_start\fP 
.PP
cgi_session_error_message 
.RE
.PP

.SS "int cgi_session_register_var (const char * name, const char * value)"
.PP
Register a variable in the current opened session.Note that we are opening and closing the session file every time this function is called... ( I/O ^ 1000000 :-/ ) 
.PP
\fBParameters:\fP
.RS 4
\fIname\fP Variable name 
.br
\fIvalue\fP Variable value 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBcgi_session_alter_var()\fP, \fBcgi_session_unregister_var()\fP 
.RE
.PP

.SS "void cgi_session_save_path (const char * path)"
.PP
Defines where session control files will be saved.If in the your CGI you don't make a call to \fBcgi_session_save_path()\fP, LibCGI will use the default value, which is '/tmp/'. To see how to modify the value, see the following example. 
.br
Just note you need to add '/' at the end of the directory name 
.PP
.nf

 // your_cgi.c
 // Set 'session_files' directory under your CGI directory as the path 
 // which LibCGI will use to store session files.
 
 cgi_session_save_path('session_files/');
  

.PP
.PP
Note that using this form, LibCGI will search for 'session_files' directory using relative path to your cgi application. For example, if your CGI script is located at /usr/local/httpd/web/your_name/cgi-bin/ directory, and you use the above declaration, the files for the session will be stored at /usr/local/httpd/web/your_name/cgi-bin/session_files directory. Resuming, the path is relative to where your application resides. 
.br

.br
And remember, LibCGI \fBdoes\fP \fBnot\fP create the directory for you.
.PP
\fBParameters:\fP
.RS 4
\fIpath\fP Path, relative or absolute 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBcgi_session_cookie_name\fP 
.RE
.PP
\fBNote:\fP
.RS 4
This function must be called before \fBcgi_session_start()\fP 
.RE
.PP

.SS "int cgi_session_start ()"
.PP
Starts a new session.This function is responsible for starting and creating a new session. It must be called before any other session function, and every time before any HTML header has sent. 
.PP
\fBSee also:\fP
.RS 4
session_destroy() 
.RE
.PP

.SS "int cgi_session_unregister_var (char * name)"
.PP
Unregister some session variable.\fBParameters:\fP
.RS 4
\fIname\fP Session variable name to unregister 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBcgi_session_var_exists()\fP, \fBcgi_session_register_var()\fP 
.RE
.PP

.SS "char* cgi_session_var (const char * var_name)"
.PP
Gets session variable's value.\fBParameters:\fP
.RS 4
\fIname\fP Session variable name to get the value 
.RE
.PP
\fBReturns:\fP
.RS 4
Variable contents if found, NULL if not. 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBcgi_session_var_exists()\fP 
.RE
.PP

.SS "int cgi_session_var_exists (const char * name)"
.PP
Searches for determined session variable.\fBParameters:\fP
.RS 4
\fIname\fP Session variable name to search 
.RE
.PP
\fBReturns:\fP
.RS 4
1 if variable is registered, 0 if not 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBcgi_session_var()\fP 
.RE
.PP