Man page of tw_parse_config(3)

tw_parse_config - parse a Textweiser configuration file

C/C++ #include <tw.h>

 tw_errno_t tw_parse_config(const char *path, tw_config_t *config);

tw_parse_config() parses a Textweiser configuration file and stores its contained configuration settings to config. Using a configuration file allows to configure Textweiser database access more easily.

path (const char *)

Path to the configuration file within the filesystem.

config (tw_config_t *)

Pointer to a configuration data structure.

It is recommended to initialize config using the TW_CONFIG_INITIALIZER macro on declaration.

config is re-initialized on any call of the function. Any settings that may have been previously stored within will be lost.

If tw_parse_config() succeeds, config will contain the settings given in the configuration file.

The syntax of Textweiser configuration files follows an easy to use key/value scheme. Empty lines and any leading/trailing whitespace is ignored. Lines starting with the character # are considered comments.

Values may be enclosed within matching single or double quotes and are assigned to keys using the = character.

host

Hostname of the database server.

user

Username for database authentification.

passwd

Password for database authentification.

db_name

Name of the Textweiser database.

port

Port number of the database server.

instance

Name of the Microsoft SQL Server instance.

encrypt

Enable/disable communication encryption.

The following values are recognized:

"yes" or "on"

Enable encryption.

"no" or "off"

Disable encryption.

In order to trust a server's certificate, append the "trust-cert" token to the value, separated by a comma and/or whitespace, i.e.

 encrypt = "yes, trust-cert"

tw_parse_config() returns an error indicator (tw_errno_t). A return value of TW_OK indicates success, any other value discriminates the occurred error.

The function tw_strerror(3) can be used to obtain a natural language error message.

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If the tw_config_t object is not needed anymore, tw_free_config_t(3) should be used to free its allocated memory.

o

Any variable of type tw_config_t should be initialized using the macro TW_CONFIG_INITIALIZER on declaration.

o

A passed config variable is re-initialized on any call of the function. Any settings that may have been previously stored within will be lost.

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Whenever the tw_config_t data structure has either been assigned to manually or modified, tw_free_config_t(3) must not be used to free the allocated memory.

 # this is a Textweiser example configuration file

 host   = "localhost"

 user   = 'test'
 passwd = 'secret'

 db_name = Textweiser

 encrypt = "yes, trust-cert"

 # port not set -> use default

C/C++ #include <stdio.h>
 #include <stdlib.h>

 #include <tw.h>

 int main(int argc, char *argv[])
 {
     tw_errno_t  rv = TW_OK;
     tw_config_t cfg;

     if (argc != 2)
     {
         fprintf(stderr, "usage: %s config-file\n", argv[0]);
         return(EXIT_FAILURE);
     }

     rv = tw_parse_config(argv[1], &cfg);

     if (rv != TW_OK)
     {
         fprintf(stderr, "Error: %s\n", tw_strerror(rv));
         return(EXIT_FAILURE);
     }

     printf("== %s ==\n\n", argv[1]);

     printf("host     -> %s\n", cfg.host     ? cfg.host     : "-");
     printf("user     -> %s\n", cfg.user     ? cfg.user     : "-");
     printf("passwd   -> %s\n", cfg.passwd   ? cfg.passwd   : "-");
     printf("db_name  -> %s\n", cfg.db_name  ? cfg.db_name  : "-");
     printf("instance -> %s\n", cfg.instance ? cfg.instance : "-");
     printf("port     -> %u\n", cfg.port);

     printf("encrypt  -> %s, trust-cert? %s\n",
            (cfg.encrypt & TW_ENCRYPT_ON         ? "On"  : "Off"),
            (cfg.encrypt & TW_ENCRYPT_TRUST_CERT ? "Yes" : "No"));

     tw_free_config_t(&cfg);

     return(EXIT_SUCCESS);
 }

The following example shows the output when used with the configuration file given in EXAMPLE CONFIGURATION FILE:

 $ ./example_parse_config example.cfg
 == example.cfg ==

 host     -> localhost
 user     -> test
 passwd   -> secret
 db_name  -> Textweiser
 instance -> -
 port     -> 0
 encrypt  -> On, trust-cert? Yes

tw_free_config_t(3), tw_strerror(3)

Textweiser User Manual

http://www.lingua-systems.com/text-classifier/textweiser-library/

Copyright (c) 2010-2011 Lingua-Systems Software GmbH