glGetProgram 3G
glGetProgramiv Returns a parameter from a program object

## C Specification

void `glGetProgramiv` GLuint program GLenum pname GLint *params

## Parameters

program

  Specifies the program object to be queried.

pname

  Specifies the object parameter. Accepted symbolic names are `GL_DELETE_STATUS`, `GL_LINK_STATUS`, `GL_VALIDATE_STATUS`, `GL_INFO_LOG_LENGTH`, `GL_ATTACHED_SHADERS`, `GL_ACTIVE_ATOMIC_COUNTER_BUFFERS`, `GL_ACTIVE_ATTRIBUTES`, `GL_ACTIVE_ATTRIBUTE_MAX_LENGTH`, `GL_ACTIVE_UNIFORMS`, `GL_ACTIVE_UNIFORM_BLOCKS`, `GL_ACTIVE_UNIFORM_BLOCK_MAX_NAME_LENGTH`, `GL_ACTIVE_UNIFORM_MAX_LENGTH`, `GL_COMPUTE_WORK_GROUP_SIZE` `GL_PROGRAM_BINARY_LENGTH`, `GL_TRANSFORM_FEEDBACK_BUFFER_MODE`, `GL_TRANSFORM_FEEDBACK_VARYINGS`, `GL_TRANSFORM_FEEDBACK_VARYING_MAX_LENGTH`, `GL_GEOMETRY_VERTICES_OUT`, `GL_GEOMETRY_INPUT_TYPE`, and `GL_GEOMETRY_OUTPUT_TYPE`.

params

  Returns the requested object parameter.

## Description

`glGetProgram` returns in params the value of a parameter for a specific program object. The following parameters are defined:

`GL_DELETE_STATUS`

  params returns `GL_TRUE` if program is currently flagged for deletion, and `GL_FALSE` otherwise.

`GL_LINK_STATUS`

  params returns `GL_TRUE` if the last link operation on program was successful, and `GL_FALSE` otherwise.

`GL_VALIDATE_STATUS`

  params returns `GL_TRUE` or if the last validation operation on program was successful, and `GL_FALSE` otherwise.

`GL_INFO_LOG_LENGTH`

  params returns the number of characters in the information log for program including the null termination character (i.e., the size of the character buffer required to store the information log). If program has no information log, a value of 0 is returned.

`GL_ATTACHED_SHADERS`

  params returns the number of shader objects attached to program.

`GL_ACTIVE_ATOMIC_COUNTER_BUFFERS`

  params returns the number of active attribute atomic counter buffers used by program.

`GL_ACTIVE_ATTRIBUTES`

  params returns the number of active attribute variables for program.

`GL_ACTIVE_ATTRIBUTE_MAX_LENGTH`

  params returns the length of the longest active attribute name for program, including the null termination character (i.e., the size of the character buffer required to store the longest attribute name). If no active attributes exist, 0 is returned.

`GL_ACTIVE_UNIFORMS`

  params returns the number of active uniform variables for program.

`GL_ACTIVE_UNIFORM_MAX_LENGTH`

  params returns the length of the longest active uniform variable name for program, including the null termination character (i.e., the size of the character buffer required to store the longest uniform variable name). If no active uniform variables exist, 0 is returned.

`GL_PROGRAM_BINARY_LENGTH`

  params returns the length of the program binary, in bytes that will be returned by a call to glGetProgramBinary. When a progam's `GL_LINK_STATUS` is `GL_FALSE`, its program binary length is zero.

`GL_COMPUTE_WORK_GROUP_SIZE`

  params returns an array of three integers containing the local work group size of the compute program as specified by its input layout qualifier(s). program must be the name of a program object that has been previously linked successfully and contains a binary for the compute shader stage.

`GL_TRANSFORM_FEEDBACK_BUFFER_MODE`

  params returns a symbolic constant indicating the buffer mode used when transform feedback is active. This may be `GL_SEPARATE_ATTRIBS` or `GL_INTERLEAVED_ATTRIBS`.

`GL_TRANSFORM_FEEDBACK_VARYINGS`

  params returns the number of varying variables to capture in transform feedback mode for the program.

`GL_TRANSFORM_FEEDBACK_VARYING_MAX_LENGTH`

  params returns the length of the longest variable name to be used for transform feedback, including the null-terminator.

`GL_GEOMETRY_VERTICES_OUT`

  params returns the maximum number of vertices that the geometry shader in program will output.

`GL_GEOMETRY_INPUT_TYPE`

  params returns a symbolic constant indicating the primitive type accepted as input to the geometry shader contained in program.

`GL_GEOMETRY_OUTPUT_TYPE`

  params returns a symbolic constant indicating the primitive type that will be output by the geometry shader contained in program.

## Notes

`GL_ACTIVE_UNIFORM_BLOCKS` and `GL_ACTIVE_UNIFORM_BLOCK_MAX_NAME_LENGTH` are available only if the GL version 3.1 or greater.

`GL_GEOMETRY_VERTICES_OUT`, `GL_GEOMETRY_INPUT_TYPE` and `GL_GEOMETRY_OUTPUT_TYPE` are accepted only if the GL version is 3.2 or greater.

`GL_COMPUTE_WORK_GROUP_SIZE` is accepted only if the GL version is 4.3 or greater.

If an error is generated, no change is made to the contents of params.

## Errors

`GL_INVALID_VALUE` is generated if program is not a value generated by OpenGL.

`GL_INVALID_OPERATION` is generated if program does not refer to a program object.

`GL_INVALID_OPERATION` is generated if pname is `GL_GEOMETRY_VERTICES_OUT`, `GL_GEOMETRY_INPUT_TYPE`, or `GL_GEOMETRY_OUTPUT_TYPE`, and program does not contain a geometry shader.

`GL_INVALID_ENUM` is generated if pname is not an accepted value.

`GL_INVALID_OPERATION` is generated if pname is `GL_COMPUTE_WORK_GROUP_SIZE` and program does not contain a binary for the compute shader stage.

## Associated Gets

glGetActiveAttrib with argument program

glGetActiveUniform with argument program

glGetAttachedShaders with argument program

glGetProgramInfoLog with argument program

glIsProgram

## See Also

glAttachShader, glCreateProgram, glDeleteProgram, glGetShader, glLinkProgram, glValidateProgram

## Copyright

Copyright 2003-2005 3Dlabs Inc. Ltd. Copyright 2010-2011 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.