Question

OpenGL header gl.h as well as many other headers contains function definitions spread over many lines. Here is an example :

GLAPI void glCopyTexSubImage2D( GLenum target, GLint level,
                                GLint xoffset, GLint yoffset,
                                GLint x, GLint y,
                                GLsizei width, GLsizei height );

I would like to come up with a regular expression that I could use with sed to align them. The previous example would then become:

GLAPI void glCopyTexSubImage2D( GLenum target, GLint level,GLint xoffset, GLint yoffset, GLint x, GLint y,GLsizei width, GLsizei height );

The GLAPI token is specific to OpenGL, so I’d rather ignore it so that the solution could be used in more contexts.

Answer 1

A Simple sed one-liner will work for you –

sed ':a;{N;s/\n */ /};ba' INPUT_FILE

Test:

[jaypal:~/Temp] cat temp
GLAPI void glCopyTexSubImage2D( GLenum target, GLint level,
                                GLint xoffset, GLint yoffset,
                                GLint x, GLint y,
                                GLsizei width, GLsizei height );

[jaypal:~/Temp] sed ':a;{N;s/\n */ /};ba' temp
GLAPI void glCopyTexSubImage2D( GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint x, GLint y, GLsizei width, GLsizei height );