open_memstream(3) Library Functions Manual open_memstream(3) open_memstream, open_wmemstream - (libc -lc) #include FILE *open_memstream(char **ptr, size_t *sizeloc); #include FILE *open_wmemstream(wchar_t **ptr, size_t *sizeloc); glibc ( feature_test_macros(7)): open_memstream(), open_wmemstream(): glibc 2.10: _POSIX_C_SOURCE >= 200809L glibc 2.10: _GNU_SOURCE open_memstream() . . . free(3). ptr sizeloc . (fflush(3)) (fclose(3)). . . . sizeloc. ( ). . fseek(3) fseeko(3). . open_wmemstream() open_memstream() . open_memstream() open_wmemstream() FILE. NULL errno . attributes(7). +------------+------------------------------------+--------------------+ || | | +------------+------------------------------------+--------------------+ |open_memstream(),| | MT-Safe | |open_wmemstream()| | | +------------+------------------------------------+--------------------+ POSIX.1-2008. open_memstream() glibc 1.0.x. open_wmemstream() glibc 2.4. ( fileno(3) ). glibc 2.7 open_memstream() fseek(3) -1. fmemopen(3). fmemopen(3), fopen(3), setbuf(3) 3 . . : . 6.18 8 2026 open_memstream(3)