Updating multiple lines

To update multiple lines, you can issue more than one EXECIO command to the same data set. For example, to update Mary Leone's user ID in addition to Amy Crandall's phone extension, write the following instructions.

Updating Multiple Specific Lines in a Data Set

"ALLOC DA('dept5.employee.list') F(updatedd) OLD"
"EXECIO 1 DISKRU updatedd 2 (LIFO"
PULL line
PUSH 'Crandall, Amy         AMY           5500'
"EXECIO 1 DISKW updatedd"
"EXECIO 1 DISKRU updatedd 5 (LIFO"
PULL line
PUSH 'Leone, Mary           MARYL         5530'
"EXECIO 1 DISKW updatedd (FINIS"
 "FREE F(updatedd)"

When you issue multiple EXECIO commands to the same data set before closing it and do not specify a line number, the most current EXECIO command begins reading where the previous one left off. Thus to scan a data set one line at a time and allow a user at a terminal to update each line, you might write the following exec.

Example of Scanning Each Line for Update

/***************************** REXX ********************************/
/* This exec scans a data set whose name and size are specified by */
/* a user.  The user is given the option of changing each line as  */
/* it appears.  If there is no change to the line, the user presses*/
/* Enter key to indicate that there is no change.  If there is a   */
/* change to the line, the user types the entire line with the     */
/* change and the new line is returned to the data set.            */
/*******************************************************************/

  PARSE ARG name numlines  /* Get data set name and size from user */

  "ALLOC DA("name") F(updatedd) OLD"
  eof = 'NO'                        /* Initialize end-of-file flag */

  DO i = 1 to numlines WHILE eof = 'NO'
    "EXECIO 1 DISKRU updatedd" /* Queue the next line on the stack */
    IF RC = 2 THEN            /* Return code indicates end-of-file */
       eof = 'YES'
    ELSE
      DO
        PARSE PULL line
        SAY 'Please make changes to the following line.'
        SAY 'If you have no changes, press ENTER.'
        SAY line
        PARSE PULL newline
        IF newline = '' THEN NOP
        ELSE
          DO
            PUSH newline
            "EXECIO 1 DISKW updatedd"
          END
      END
  END