read man page on Minix

Man page or keyword search:  
man Server   6208 pages
apropos Keyword Search (all sections)
Output format
Minix logo
[printable version]

READ(2)								       READ(2)

NAME
       read, pread - read input

SYNOPSIS
       #include <sys/types.h>
       #include <unistd.h>

       ssize_t read(int d, void *buf, size_t nbytes)
       ssize_t pread(int d, void *buf, size_t nbytes, off_t offset)

DESCRIPTION
       Read  attempts to read nbytes of data from the object referenced by the
       descriptor d into the buffer pointed to by buf.

       On objects capable of seeking, the read starts at a position  given  by
       the  pointer  associated with d (see lseek(2)).	Upon return from read,
       the pointer is incremented by the number of bytes actually read.

       Objects that are not capable of seeking always read  from  the  current
       position.   The	value of the pointer associated with such an object is
       undefined.

       Upon successful completion, read return the number  of  bytes  actually
       read  and placed in the buffer.	The system guarantees to read the num‐
       ber of bytes requested if the descriptor references a normal file  that
       has that many bytes left before the end-of-file, but in no other case.

       If the returned value is 0, then end-of-file has been reached.

       The  pread  system call performs the same functions, but reads from the
       specified position in the file without modifying the file pointer.

RETURN VALUE
       If successful, the number of bytes actually read is  returned.	Other‐
       wise, a -1 is returned and the global variable errno is set to indicate
       the error.

ERRORS
       Read and pread will fail if one or more of the following are true:

       [EBADF]	      D is not a valid descriptor open for reading.

       [EFAULT]	      Buf points outside the allocated address space.

       [EIO]	      An I/O error occurred while reading from the  file  sys‐
		      tem.

       [EINTR]	      A	 read  from  a	slow device was interrupted before any
		      data arrived by the delivery of a signal.

       [EAGAIN]	      The file was marked for non-blocking I/O,	 and  no  data
		      were ready to be read.

       The pread system call may also return any of the lseek errors.

SEE ALSO
       dup(2), fcntl(2), open(2), pipe(2), lseek(2), write(2).

NOTES
       pread  is currently implemented as a library function instead of a sys‐
       tem call.

4th Berkeley Distribution	 May 23, 1986			       READ(2)
[top]

List of man pages available for Minix

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net