Reentrant covers for OS subroutines

Since the system subroutines are used by other library routines that require reentrancy, `libc.a' provides cover routines (for example, the reentrant version of fork is _fork_r). These cover routines are consistent with the other reentrant subroutines in this library, and achieve reentrancy by using a reserved global data block (see section Reentrancy).

_open_r

A reentrant version of open. It takes a pointer to the global data block, which holds errno.

int _open_r(void *reent,
    const char *file, int flags, int mode);

_close_r

A reentrant version of close. It takes a pointer to the global data block, which holds errno.

int _close_r(void *reent, int fd);

_lseek_r

A reentrant version of lseek. It takes a pointer to the global data block, which holds errno.

off_t _lseek_r(void *reent,
    int fd, off_t pos, int whence);

_read_r

A reentrant version of read. It takes a pointer to the global data block, which holds errno.

long _read_r(void *reent,
    int fd, void *buf, size_t cnt);

_write_r

A reentrant version of write. It takes a pointer to the global data block, which holds errno.

long _write_r(void *reent,
    int fd, const void *buf, size_t cnt);

_fork_r

A reentrant version of fork. It takes a pointer to the global data block, which holds errno.

int _fork_r(void *reent);

_wait_r

A reentrant version of wait. It takes a pointer to the global data block, which holds errno.

int _wait_r(void *reent, int *status);

_stat_r

A reentrant version of stat. It takes a pointer to the global data block, which holds errno.

int _stat_r(void *reent,
    const char *file, struct stat *pstat);

_fstat_r

A reentrant version of fstat. It takes a pointer to the global data block, which holds errno.

int _fstat_r(void *reent,
    int fd, struct stat *pstat);

_link_r

A reentrant version of link. It takes a pointer to the global data block, which holds errno.

int _link_r(void *reent,
    const char *old, const char *new);

_unlink_r

A reentrant version of unlink. It takes a pointer to the global data block, which holds errno.

int _unlink_r(void *reent, const char *file);

_sbrk_r

A reentrant version of sbrk. It takes a pointer to the global data block, which holds errno.

char *_sbrk_r(void *reent, size_t incr);