SAS/C Library Reference, Vol. 1

kseek -- Reposition a Keyed Stream

SYNOPSIS

 #include <lcio.h>

 int kseek(FILE *f, int pos);

DESCRIPTION

The kseek function repositions the stream associated with the FILE object addressed by f, as specified by the value of pos, and releases control of any current record. The pos value must be either SEEK_SET, SEEK_CUR, or SEEK_END. (These constants are defined in <stdio.h>.) Each of these values refers to a specific location in the file, as follows:

SEEK_SET: refers to the start of file.
SEEK_CUR: refers to the current file position.
SEEK_END: refers to the end of file.

If the current record is read for update, the record is released and is read for update by another FILE object. Even though kseek with pos value SEEK_CUR causes no change in the file's positioning, it is still useful to release control of the current record.

RETURN VALUES

The kseek function returns 0 if successful, or a negative value if an error occurred.

EXAMPLE

This example retrieves the last record in a VSAM file:

  #include <lcio.h>

  int getlast(FILE *f, void *buf)
  {
     int length;
     rc = kseek(f, SEEK_END);
     if (rc < 0) return rc;    /* in case it fails */
        /* Retrieve backwards from EOF.            */
     length = kretrv(buf, NULL, K_BACKWARDS, f);
     return length;
  }

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