.TH IM_VIPSHOME 3 "8 March 2001"
.SH NAME
im_guess_prefix, im_guess_libdir \- try to guess install directory
.SH SYNOPSIS
.B #include <vips/vips.h>

.B const char *im_guess_prefix( const char *argv0,
.B     const char *env_name )

.B const char *im_guess_libdir( const char *argv0,
.B     const char *env_name )

.SH DESCRIPTION
.B im_guess_prefix(3) 
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, 
.B im_guess_prefix(3) 
returns the prefix it discovered, and as a side effect, sets the environment
variable (if it's not set).

.B im_guess_prefix(3) 
is useful for programs in the VIPS distribution and contrib which need to be
able to find data files.

Don't free the return string!

.B im_guess_libdir(3) 
works exactly as 
.B im_guess_prefix(3) 
but, if vips has not been moved since configure, returns the libdir configure
setting. If vips has been moved, it returns prefix/lib.

.SH RETURN VALUE
The function returns NULL on failure.