--- /dev/null
+CHDIR(2)
+## NAME
+chdir - change working directory
+## SYNOPSIS
+*#include <unistd.h>*
+
+*int chdir*(*const char \**path);\
+
+*int fchdir*(*int* fd);
+## DESCRIPTION
+The *chdir*() call changes the current working directory of the caller to
+that specified by *path*.
+
+The *fchdir* call changes the current working directory to that referred to
+by *fd*.
+## RETURN VALUE
+On success, zero is returned. On error -1 is returned and errno is set.
+## ERRORS
+:*EACCES*
+ Insufficient permission is available to walk the path
+:*EBADF*
+ The file descriptor *fd* is not valid.
+:*EFAULT*
+ The address passed for the path is invalid.
+:*EIO*
+ An I/O error occurred.
+:*ENOENT*
+ The path does not exist.
+:*ENOMEM*
+ No memory was available.
+:*ENOTDIR*
+ An element of the path is not a directory or *fd* does not
+ refer to a directory
+## CONFORMING TO
+V7, UZI, POSIX.1-2001.
+## NOTES
+It is possible to save and restore the current working directory as follows
+
+ int fd = open(".", O_RDONLY);
+ ...
+ fchdir(fd);
+ close(fd);
+
+## SEE ALSO
+*chroot*(2), *getcwd*(3).
--- /dev/null
+LSEEK(2)
+## NAME
+lseek - set or report the file offset
+## SYNOPSIS
+*#include <sys/types.h>*\
+
+*#include <unistd.h>*
+
+*off\_t lseek*(*int* fd, *off\_t* offset, int whence);
+## DESCRIPTION
+The *lseek*() call allows the offset of the file table entry referred to by
+file descriptor *fd* to be queried or changed.
+
+The *whence* value controls the nature of the change and three behaviours are
+available.
+
+:*SEEK\_SET*
+ The offset is set to *offset* characters into the file.
+:*SEEK\_CUR*
+ The offset is moved relative to the current position.
+:*SEEK\_END*
+ The offset is set relative to the end of file. The offset passed must be
+ zero or negative.
+
+Fuzix permits the offset to be set beyond the current end of file. The end of
+file position is not changed by this action, but a write of data at that
+position will extend the file.
+## RETURN VALUE
+If the operation succeeds the previous value of the offset is returned. If an
+error occurs (off\_t)-1 is returned, errno is set and the offset remains
+unmodified.
+## ERRORS
+:*EBADF*
+ The file descriptor *fd* is not open.
+:*EFAULT*
+ The address passed for the arguments is invalid.
+:*EINVAL*
+ The *whence* value is not valid, or the resulting offset is negative or beyond
+ the permitted maximum size of the object.
+:*EIO*
+ An I/O error occurred.
+:*EOVERFLOW*
+ The resulting file offset does not fit in an off\_t.
+:*ESPIPE:
+ The file descriptor points to an object (eg a pipe) that does not support
+ the lseek operation.
+## CONFORMING TO
+V7, POSIX.1-2001.
+## NOTES
+The current file position can be read without modification by calling\
+
+*lseek*(*fd*, 0, 0)
+
+Fuzix implements lseek as a wrapper around an _lseek system call entry.
+
+Fuzix will not currently report *EOVERFLOW*.
+## SEE ALSO
+*lseek*(2), *open*(2), *write*(2).
+
--- /dev/null
+SYNC(2)
+## NAME
+sync - write changes to stable storage
+## SYNOPSIS
+*#include <unistd.h>*
+
+*void sync*(*void*);\
+
+## DESCRIPTION
+When *sync*() is called all buffered modifications to files and to metadata are
+committed to the underlying storage.
+## RETURN VALUE
+None.
+## ERRORS
+None.
+## CONFORMING TO
+V7, UZI, POSIX.1-2001.
+## SEE ALSO
+*fdatasync*(3), *fsync*(3)
--- /dev/null
+WRITE(2)
+## NAME
+write - write data to a file descriptor
+## SYNOPSIS
+*#include <unistd.h>*
+
+*ssize\_t write*(*int* fd, *const void* \*buf, *size\_t* count);
+## DESCRIPTION
+The *write*() call writes up to the specified *count* of bytes from the buffer
+*buf* to the object referenced by file descriptor *fd*.
+
+On files that support seeking the write begins at the current file offset and
+the file offset is incremented by the number of bytes writren. A write will extend
+the file. If the *O\_APPEND* flag was specified for this file then the file
+offset is set to the end of the file before the write occurs, and it and the
+write occur as one atomic operation.
+
+If the count is zero then zero will be returned. If the count is larger than
+*SSIZE\_MAX* an error will be returned.
+
+A write from a device such as a *socket*(4), *tty*(4) or *fifo*(7) may block and
+wait for space to write data. This behaviour is controlled by the *O\_NDELAY*
+flag when opening the file. Waiting *write* calls may also be interrupted by a
+*signal*(7).
+## RETURN VALUE
+On success, the number of bytes successfully written is returned.
+If no data could be written due to an error then -1 is returned and errno is set.
+## ERRORS
+:*EAGAIN*
+ The write would block but the *O\_NDELAY* flag is set on the file descriptor.
+:*EBADF*
+ The file descriptor *fd* is not open for writing.
+:*EFAULT*
+ The address passed for the path is invalid.
+:*EINTR*
+ The write was interrupted by a *signal*(7) before any data was read.
+:*EINVAL*
+ The file descriptor refers to an object which does not support this operation
+ or the count specified exceeds *SSIZE\_MAX*.
+:*EIO*
+ An I/O error occurred.
+:*ENOSPC*
+ No space was available to write the new data.
+:*EPIPE*
+ A write to a pipe or socket was attempted when there is no reader. The writing
+ process will also receive a *SIGPIPE* signal.
+## CONFORMING TO
+V7, UZI, POSIX.1-2001.
+## NOTES
+The behaviour of a *write*(2) when passed a count larger than *SSIZE\_MAX* is
+undefined by the standards. Fuzix returns *EINVAL* to provide a clear defined
+behaviour because on an 8 or 16bit machine it is relatively easy to accidentally
+hit this limit.
+## SEE ALSO
+*lseek*(2), *open*(2), *write*(2), *socket*(4), *tty*(4), *signal*(7)
public / FUZIX.git / commitdiff