|OPEN_MEMSTREAM(3)||Linux Programmer's Manual||OPEN_MEMSTREAM(3)|
FILE *open_memstream(char **ptr, size_t *sizeloc); #include <wchar.h>
FILE *open_wmemstream(wchar_t **ptr, size_t *sizeloc);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
- Since glibc 2.10:
- _POSIX_C_SOURCE >= 200809L
- Before glibc 2.10:
The locations pointed to by ptr and sizeloc are used to report, respectively, the current location and the size of the buffer. The locations referred to by these pointers are updated each time the stream is flushed (fflush(3)) and when the stream is closed (fclose(3)). These values remain valid only as long as the caller performs no further output on the stream. If further output is performed, then the stream must again be flushed before trying to access these values.
A null byte is maintained at the end of the buffer. This byte is not included in the size value stored at sizeloc.
The stream maintains the notion of a current position, which is initially zero (the start of the buffer). Each write operation implicitly adjusts the buffer position. The stream's buffer position can be explicitly changed with fseek(3) or fseeko(3). Moving the buffer position past the end of the data already written fills the intervening space with null characters.
The open_wmemstream() is similar to open_memstream(), but operates on wide characters instead of bytes.
|open_memstream (), open_wmemstream||Thread safety||MT-Safe|