Sample Code for Recall File Position

This example opens a previously-closed file, uses a previous file pointer, and recalls the stored file pointer's saved position. It then reads in data from that position. This code illustrates the use of the FILE/RECALL_POSITION command. It continues the code sample given in the "Sample Code for Save File Position" topic.

COMMENT/OPER,The routine will now recall the stored file position.

FPTR=FILE/OPEN,C1.INPUT,READ

FILE/REWIND,FPTR

COMMENT/OPER,To test, file has been rewound.

,The first line will be read in to test the rewind.

V3=FILE/READLINE,FPTR,{LINE}

COMMENT/OPER,The first line is:

,LINE

FILE/REWIND,FPTR

FILE/RECALL_POSITION,FPTR

COMMENT/OPER,Previously stored file position has been recalled.

,Data on the line at the stored position will now print.

V4=FILE/READLINE,FPTR,{STORED}

COMMENT/OPER,The text at the stored position is:

,STORED

Code Explanation

This code is similar to that explained in "Sample Code for Rewind to Start".

Only explanations unique to this example are given here.

FILE/RECALL_POSITION,FPTR
This line recalls the stored file pointer position in the file stream for the file pointer designated as FPTR.

V4=FILE/READLINE,FPTR,{STORED}
This line reads in the next line after the stored file pointer position and assigns it to the user-defined variable of STORED. This variable is then printed out in the next operator comment.