FcConfigSubstitute (3) - Linux Manuals
FcConfigSubstitute: Execute substitutions
NAME
FcConfigSubstitute - Execute substitutions
SYNOPSIS
#include <fontconfig/fontconfig.h>
FcBool FcConfigSubstitute (FcConfig *config, FcPattern *p, FcMatchKind kind);
DESCRIPTION
Calls FcConfigSubstituteWithPat setting p_pat to NULL. Returns FcFalse if the substitution cannot be performed (due to allocation failure). Otherwise returns FcTrue. If config is NULL, the current configuration is used.