## Version Information

Version Information — Variables and functions to check the GLib version

## Synopsis

    #include <glib.h>

    extern              const guint glib_major_version;
    extern              const guint glib_minor_version;
    extern              const guint glib_micro_version;
    extern              const guint glib_binary_age;
    extern              const guint glib_interface_age;
    const gchar *       glib_check_version                  (guint required_major,
                                                             guint required_minor,
                                                             guint required_micro);

    #define             GLIB_MAJOR_VERSION
    #define             GLIB_MINOR_VERSION
    #define             GLIB_MICRO_VERSION
    #define             GLIB_CHECK_VERSION                  (major,
                                                             minor,
                                                             micro)

## Description

GLib provides version information, primarily useful in configure checks for builds that have a configure script. Applications will not typically use the features described here.

## Details

### glib_major_version

    extern const guint glib_major_version;

### glib_minor_version

    extern const guint glib_minor_version;

### glib_micro_version

    extern const guint glib_micro_version;

### glib_binary_age

    extern const guint glib_binary_age;

### glib_interface_age

    extern const guint glib_interface_age;

### glib_check_version ()

    const gchar *       glib_check_version                  (guint required_major,
                                                             guint required_minor,
                                                             guint required_micro);

Checks that the GLib library in use is compatible with the given version. Generally you would pass in the constants GLIB_MAJOR_VERSION, GLIB_MINOR_VERSION, GLIB_MICRO_VERSION as the three arguments to this function; that produces a check that the library in use is compatible with the version of GLib the application or module was compiled against.

Compatibility is defined by two things: first the version of the running library is newer than the version `required_major.required_minor`.`required_micro`. Second the running library must be binary compatible with the version `required_major.required_minor`.`required_micro` (same major version.)

`required_major` : | the required major version.
`required_minor` : | the required minor version.
`required_micro` : | the required micro version.
Returns : | `NULL` if the GLib library is compatible with the given version, or a string describing the version mismatch. The returned string is owned by GLib and must not be modified or freed.

Since 2.6

### GLIB_MAJOR_VERSION

    #define GLIB_MAJOR_VERSION 2

The major version number of the GLib library. Like glib_major_version, but from the headers used at application compile time, rather than from the library linked against at application run time.

### GLIB_MINOR_VERSION

    #define GLIB_MINOR_VERSION 29

The minor version number of the GLib library. Like gtk_minor_version, but from the headers used at application compile time, rather than from the library linked against at application run time.

### GLIB_MICRO_VERSION

    #define GLIB_MICRO_VERSION 10

The micro version number of the GLib library. Like gtk_micro_version, but from the headers used at application compile time, rather than from the library linked against at application run time.

### GLIB_CHECK_VERSION()

    #define             GLIB_CHECK_VERSION(major,minor,micro)

Checks the version of the GLib library. Returns `TRUE` if the version of the GLib header files is the same as or newer than the passed-in version.

Example 1. Checking the version of the GLib library

    1
    2

    if (!GLIB_CHECK_VERSION (1, 2, 0))
      g_error ("GLib version 1.2.0 or above is needed");

`major` : | the major version number.
`minor` : | the minor version number.
`micro` : | the micro version number.