lseek(2) — AIX PS/2 1.2.1



LSEEK(2,L)                  AIX Technical Reference                  LSEEK(2,L)



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lseek



PURPOSE

Moves read/write file pointer.

SYNTAX

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

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

DESCRIPTION

The lseek system call sets the file pointer for the file specified by the
fildes parameter.

The fildes parameter is a file descriptor obtained from a creat, open, dup, or
fcntl system call.

The lseek system call sets the file pointer associated with the fildes stream
according to the value of the whence parameter, as follows:

SEEK_SET   Sets the file pointer to the value of the offset parameter.

SEEK_CUR   Sets the file pointer to its current location plus the value of the
           offset parameter.

SEEK_END   Sets the file pointer to the size of the file plus the value of the
           offset parameter.

RETURN VALUE

Upon successful completion, the resulting pointer location as measured in bytes
from the beginning of the file is returned.  A negative value may be returned
if the offset parameter was negative; errno is not set.  If lseek fails, a
value of -1 is returned and errno is set to indicate the error.

ERROR CONDITIONS

The lseek system call fails and the file pointer remains unchanged if one or
more of the following are true:

EBADF     fildes is not an open file descriptor.




Processed November 7, 1990        LSEEK(2,L)                                  1



LSEEK(2,L)                  AIX Technical Reference                  LSEEK(2,L)



ESPIPE    fildes is associated with a pipe (FIFO) or a multiplexed special
          file.

EINVAL    whence is not SEEK_SET, SEEK_CUR, or SEEK_END.

If the Transparent Computing Facility is installed on your system, lseek can
also fail if one or more of the following are true:

ESITEDN1  The file identified by fildes cannot be accessed because a site went
          down.

ESITEDN2  The operation was terminated because a site failed.

RELATED INFORMATION

In this book:  "dup," "fcntl, flock, lockf," "fseek, rewind, ftell," and "open,
openx, creat."






































Processed November 7, 1990        LSEEK(2,L)                                  2

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