manpagez: man pages & more
html files: libvips
Home | html | info | man

vips

vips — startup, shutdown, version

Stability Level

Stable, unless otherwise indicated

Includes

#include <vips/vips.h>

Description

Start VIPS up, shut VIPS down, get version information, relocation.

VIPS is a relocatable package, meaning you can move the directory tree you compiled it to at runtime and it will still be able to find all data files. This is required for OS X and Windows, but slightly unusual in the Unix world. See vips_init() and vips_guess_prefix().

Functions

VIPS_INIT()

#define             VIPS_INIT( ARGV0 )

VIPS_INIT is deprecated and should not be used in newly-written code.

VIPS_INIT() starts up the world of VIPS. You should call this on program startup before using any other VIPS operations. If you do not call VIPS_INIT(), VIPS will call it for you when you use your first VIPS operation, but it may not be able to get hold of ARGV0 and VIPS may therefore be unable to find its data files. It is much better to call this macro yourself.

Additionally, VIPS_INIT() can be run from any thread, but it must not be called from more than one thread at the same time. This is much easier to guarantee if you call it yourself.

VIPS_INIT() is a macro, since it tries to check ABI compatibility between the caller and the library. You can also call vips_init(), the non-macro version, if macros are not available to you.

You may call VIPS_INIT() many times and vips_shutdown() many times, but you must not call VIPS_INIT() after vips_shutdown(). In other words, you cannot stop and restart vips.

VIPS_INIT() does approximately the following:

  • checks that the libvips your program is expecting is binary-compatible with the vips library you're running against

  • initialises any libraries that VIPS is using, including GObject and the threading system, if neccessary

  • guesses where the VIPS data files are and sets up internationalisation --- see vips_guess_prefix()

  • creates the main vips types, including VipsImage and friends

  • loads any plugins from $libdir/vips-x.y/, where x and y are the major and minor version numbers for this VIPS.

  • if your platform supports atexit(), VIPS_INIT() will ask for vips_shutdown() to be called on program exit

Example:

1
2
3
4
5
6
7
8
9
int main (int argc, char **argv)
{
  if (VIPS_INIT (argv[0]))
    vips_error_exit ("unable to start VIPS");

  vips_shutdown ();

  return 0;
}

See also: vips_shutdown(), vips_add_option_entries(), vips_version(), vips_guess_prefix(), vips_guess_libdir().

Parameters

ARGV0

name of application

 

Returns

0 on success, -1 otherwise

vips_init ()

int
vips_init (const char *argv0);

This function starts up libvips, see VIPS_INIT().

This function is for bindings which need to start up vips. C programs should use the VIPS_INIT() macro, which does some extra checks.

See also: VIPS_INIT().

Parameters

argv0

name of application

 

Returns

0 on success, -1 otherwise

vips_get_argv0 ()

const char *
vips_get_argv0 (void);

See also: VIPS_INIT().

Returns

a pointer to an internal copy of the argv0 string passed to VIPS_INIT(). Do not free this value

vips_shutdown ()

void
vips_shutdown (void);

Call this to drop caches and close plugins. Run with "--vips-leak" to do a leak check too.

You may call VIPS_INIT() many times and vips_shutdown() many times, but you must not call VIPS_INIT() after vips_shutdown(). In other words, you cannot stop and restart vips.

vips_thread_shutdown ()

void
vips_thread_shutdown (void);

Free any thread-private data and flush any profiling information.

This function needs to be called when a thread that has been using vips exits. It is called for you by vips_shutdown() and for any threads created by vips_g_thread_new().

You will need to call it from threads created in other ways or there will be memory leaks. If you do not call it, vips will generate a warning message.

It may be called many times, and you can continue using vips after calling it. Calling it too often will reduce performance.

vips_add_option_entries ()

void
vips_add_option_entries (GOptionGroup *option_group);

Add the standard vips GOptionEntry to a GOptionGroup.

See also: g_option_group_new().

Parameters

option_group

group to add to

 

vips_leak_set ()

void
vips_leak_set (gboolean leak);

Turn on or off vips leak checking. See also --vips-leak and vips_add_option_entries().

You should call this very early in your program.

Parameters

leak

turn leak checking on or off

 

vips_version_string ()

const char *
vips_version_string (void);

Get the VIPS version as a static string, including a build date and time. Do not free.

Returns

a static version string.

[transfer none]

vips_version ()

int
vips_version (int flag);

Get the major, minor or micro library version, with flag values 0, 1 and 2.

Get the ABI current, revision and age (as used by libtool) with flag values 3, 4, 5.

Parameters

flag

which field of the version to get

 

Returns

library version number

vips_guess_prefix ()

const char *
vips_guess_prefix (const char *argv0,
                   const char *env_name);

vips_guess_prefix() tries to guess the install directory. You should pass in the value of argv[0] (the name your program was run as) as a clue to help it out, plus the name of the environment variable you let the user override your package install area with (eg. "VIPSHOME").

On success, vips_guess_prefix() returns the prefix it discovered, and as a side effect, sets the environment variable (if it's not set).

Don't free the return string!

See also: vips_guess_libdir().

Parameters

argv0

program name (typically argv[0])

 

env_name

save prefix in this environment variable

 

Returns

the install prefix as a static string, do not free.

[transfer none]

vips_guess_libdir ()

const char *
vips_guess_libdir (const char *argv0,
                   const char *env_name);

vips_guess_libdir() tries to guess the install directory (usually the configure libdir, or $prefix/lib). You should pass in the value of argv[0] (the name your program was run as) as a clue to help it out, plus the name of the environment variable you let the user override your package install area with (eg. "VIPSHOME").

On success, vips_guess_libdir() returns the libdir it discovered, and as a side effect, sets the prefix environment variable (if it's not set).

Don't free the return string!

See also: vips_guess_prefix().

Parameters

argv0

program name (typically argv[0])

 

env_name

save prefix in this environment variable

 

Returns

the libdir as a static string, do not free.

[transfer none]

Types and Values

See Also

VipsOperation
© manpagez.com 2000-2017
Individual documents may contain additional copyright information.