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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2025-01-17 14:37:38 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2025-01-17 14:37:38 -0500 |
| commit | 86e4efc52b664b60f9494e062bbf0454cabcb61f (patch) | |
| tree | aa59b403af8088c07178c3b040fdc484d388d6e1 /src/tutorial/funcs.c | |
| parent | 43830ecb8a9b6a1bc322298a77a5e0d87c2e83d4 (diff) | |
| download | postgresql-86e4efc52b664b60f9494e062bbf0454cabcb61f.tar.gz postgresql-86e4efc52b664b60f9494e062bbf0454cabcb61f.zip | |
Add documentation about calling version-1 C functions from C.
This topic wasn't really covered before, so fill in some details.
Author: Florents Tselai <florents.tselai@gmail.com>
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/90853055-5BBD-493D-91E5-721677C7C59B@gmail.com
Diffstat (limited to 'src/tutorial/funcs.c')
| -rw-r--r-- | src/tutorial/funcs.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/tutorial/funcs.c b/src/tutorial/funcs.c index f597777a1ff..4a61177567c 100644 --- a/src/tutorial/funcs.c +++ b/src/tutorial/funcs.c @@ -11,6 +11,7 @@ #include "postgres.h" /* general Postgres declarations */ #include "executor/executor.h" /* for GetAttributeByName() */ +#include "utils/fmgrprotos.h" /* for text_starts_with() */ #include "utils/geo_decls.h" /* for point type */ PG_MODULE_MAGIC; @@ -102,6 +103,25 @@ concat_text(PG_FUNCTION_ARGS) PG_RETURN_TEXT_P(new_text); } +/* A wrapper around starts_with(text, text) */ + +PG_FUNCTION_INFO_V1(t_starts_with); + +Datum +t_starts_with(PG_FUNCTION_ARGS) +{ + text *t1 = PG_GETARG_TEXT_PP(0); + text *t2 = PG_GETARG_TEXT_PP(1); + Oid collid = PG_GET_COLLATION(); + bool result; + + result = DatumGetBool(DirectFunctionCall2Coll(text_starts_with, + collid, + PointerGetDatum(t1), + PointerGetDatum(t2))); + PG_RETURN_BOOL(result); +} + /* Composite types */ PG_FUNCTION_INFO_V1(c_overpaid); |