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lseek(2)                          SDK R4.11                         lseek(2)


NAME
       lseek - change the position of an object pointer

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

       offt  lseek (fildes, offset, whence)
       int    fildes;
       offt  offset;
       int    whence;

DESCRIPTION
       Use lseek(2) to change the position of an object pointer:

       fildes    is the pointer to be changed: a valid, active file
                 descriptor having a current position attribute.

       offset    is the new position of the file pointer.

       whence    is one of these three values specifying whether offset is
                 an absolute or incremental address:

                 SEEK_SET  Set fildes to offset bytes.

                 SEEK_CUR  Set fildes to (fildes + offset) bytes.

                 SEEK_END  Set fildes to (sizeof(fildes) + offset) bytes.

       The size of character special files and block special files is always
       zero.  Hence, where fildes points to a character or block special
       file, SEEK_END and SEEK_SET are equivalent.

       If lseek fails, the object pointer is not changed.

ACCESS CONTROL
       None.

RETURN VALUE
       position  Completed successfully.  The object pointer's new position
                 is returned.

       -1        An error occurred.  errno is set to indicate the error.

DIAGNOSTICS
       Errno may be set to one of the following error codes:

       EBADF     Fildes is not a valid, active descriptor.

       ESPIPE    Fildes is associated with a pipe or a socket.

       EINVAL    The resulting file pointer would be negative.

SEE ALSO
       creat(2), dup(2), dup2(2), fcntl(2), open(2).


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Typewritten Software • bear@typewritten.org • Edmonds, WA 98026