XTRAN Example — Command-Driven Text Processing Utility

Scenario — you have received a COBOL program listing file created by the Source Entry Utility (SEU) on an IBM iSeries computer, and you want to retrieve the original COBOL code.  The problem is that, in creating the listing, SEU has:

XTRAN to the rescue!

The following example uses an XTRAN rule set comprising 276 non-comment lines of "meta-code" (XTRAN's rules language) that implements ProcText, a command-driven text processing utility.  The rules took 3¼ hours to design, create, and debug.  (That's right, only 3¼ hours!)

ProcText supports the following text processing commands, which it reads from a specified command file:

Command syntax Description
DC,<stcol>,[[<numcol>]],
  [[<dcrgx>]]
Delete columns from each line, optionally only if the line matches a regular expression
DL,<numlin>,<dlrgx> Delete lines, starting with a line that matches a regular expression
TB,[[<tabsiz>]] Tabify lines before writing them out, based on a tab size
TR Trim trailing spaces on each line, after all DC commands have been applied
UT,[[<utbsiz>]] Untabify lines before applying DC commands, based on a tab size

where:

<dcrgx>   (optional) is a regular expression an input line must match for this DC command to be applied.  ProcText first replaces each underscore in <dcrgx> with a space.
<dlrgx> is a regular expression an input line must match for this DL command to be applied; ProcText then deletes <numlin> lines starting with the matching lineProcText first replaces each underscore in <dlrgx> with a space.
<numcol> (optional) is the number of columns for this DC command to delete, defaulting to the rest of the line.
<numlin> is the number of lines for this DL command to delete.
<stcol> is the 1-n starting column for this DC command.
<tabsiz> (optional) is the number of columns for each TAB, defaulting to 8.
<utbsiz> (optional) is the number of columns for each TAB, defaulting to 8.

You can specify multiple DC and DL commands, as needed.


In the example below, we use the following set of ProcText commands to clean up SEU listings:

; Delete SEU's listing headers:
; 
DL,4,SEU_SOURCE_LISTING
;
; Delete SEU's "end of source" line:
; 
DL,1,E_N_D__O_F__S_O_U_R_C_E
;
; Delete line numbers SEU added -- columns 1-8:
;
DC,1,8
;
; Delete update info SEU added -- columns 88-end:
;
DC,88
;
; Trim trailing blanks, as in the original code:
;
TR

The sample input shown below is from actual iSeries COBOL code that has been obfuscated to protect confidentiality and shortened for demonstration purposes.  After applying the ProcText commands shown above to the untouched SEU listing, the result was identical, character for character, to the original COBOL code from which the listing was made.

Because of ProcText's generality, you can use it to automate a broad range of text processing.  For instance, you can use it to retabify text from one TAB size to another, by simply specifying a UT command and a TB command with different TAB sizes.

How can such a powerful and versatile command-driven text processing utility be created in only 3¼ hours and only 276 lines of XTRAN rules?  Because there is so much capability already available as part of XTRAN's rules language.  These rules take advantage of the following functionality:

The input to and output from XTRAN are untouched.



Process Flowchart

Here is a flowchart for this process, in which the elements are color coded:

data flowchart

Input to XTRAN ProcText rules:

  XXXXXXX XXXXXX  111111                  SEU SOURCE LISTING                            00/00/00 00:00:00    XXXXXXXX     PAGE    1
  SOURCE FILE . . . . . . .  XXXXXX/XXXXXXX
  MEMBER  . . . . . . . . .  XXXXXXX
  SEQNBR*...+... 1 ...+... 2 ...+... 3 ...+... 4 ...+... 5 ...+... 6 ...+... 7 ...+... 8 ...+... 9 ...+... 0
    100        PROCESS XXXXX                                                                                            00/00/00
    200        IDENTIFICATION DIVISION.                                                                                 00/00/00
    300        PROGRAM-ID.   XXXXXXX.                                                                                   00/00/00
    400        AUTHOR.  XXXXXXXXXXXXX.                                                                                  10/00/00
    500        DATE-WRITTEN. 00/00/00.                                                                                  00/00/00
    600  **********************************************************************                                         10/00/00
    700        ENVIRONMENT DIVISION.                                                                                    00/00/00
    800        CONFIGURATION SECTION.                                                                                   00/00/00
    900        SOURCE-COMPUTER. IBM-AS400.                                                                              00/00/00
   1000        OBJECT-COMPUTER. IBM-AS400.                                                                              00/00/00
   1100        SPECIAL-NAMES. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX                                                       00/00/00
   1200                       XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX                                                         10/00/00
   1300                       XXXXXXXXXXXXXXXXXXXXXXXXXXXXX.                                                            10/00/00
   1400        INPUT-OUTPUT SECTION.                                                                                    00/00/00
   1500        FILE-CONTROL.                                                                                            00/00/00
   1600                                                                                                                 00/00/00
   1601            SELECT XXXXXXXXXXX                                                                                   00/00/00
   1602                ASSIGN TO XXXXXXXXXXXXXXX                                                                        00/00/00
   1603                ORGANIZATION IS INDEXED                                                                          00/00/00
   1604                ACCESS IS DYNAMIC                                                                                00/00/00
   1605                RECORD KEY IS XXXXXXXXXXXXXXXXXXXXXXXX                                                           00/00/00
   1606                FILE STATUS IS XXXXXXXXXXXXXX.                                                                   00/00/00
   1607                                                                                                                 00/00/00
  XXXXXXX XXXXXX  111111                  SEU SOURCE LISTING                            00/00/00 00:00:00    XXXXXXXX     PAGE    2
  SOURCE FILE . . . . . . .  XXXXXX/XXXXXXX
  MEMBER  . . . . . . . . .  XXXXXXX
  SEQNBR*...+... 1 ...+... 2 ...+... 3 ...+... 4 ...+... 5 ...+... 6 ...+... 7 ...+... 8 ...+... 9 ...+... 0
   2300        DATA DIVISION.                                                                                           00/00/00
   2400        FILE SECTION.                                                                                            00/00/00
   2500                                                                                                                 00/00/00
   2501        FD  XXXXXXXXXXX                                                                                          00/00/00
   2502            LABEL RECORDS ARE STANDARD.                                                                          00/00/00
   2503        01  XXXXXXXXXXX.                                                                                         00/00/00
   2504            COPY XXXXXXXXXXXXXXX OF XXXXXX.                                                                      00/00/00
   2505                                                                                                                 00/00/00
   3000        WORKING-STORAGE SECTION.                                                                                 00/00/00
   3100       *--------------------------------------------------------------*                                          00/00/00
   3200       *                  Xxxxxxxxxxxxxxxxxxxxxxxxxxx                 *                                          00/00/00
   3300       *--------------------------------------------------------------*                                          00/00/00
   3400        01  XXXXXXXXXXXXXXXXXXX.                                                                                 00/00/00
   3500            05  XXXXXXXXXXXXXX.                                                                                  00/00/00
   3600                10  XXXXXXXXXXXXXXXX     PIC X(00) VALUE 'XXXXXXX'.                                              00/00/00
   3700                10  XXXXXXXXXXXXXXXXXX   PIC X(00) VALUE 'XXXXXX'.                                               00/00/00
   3800                    88  XXXXXXXXXXXXXX   VALUE 'XXXXX'.                                                          00/00/00
   3900                    88  XXXXXXXXXXXXXXX  VALUE 'XXXXXX'.                                                         00/00/00
   4000                10  XXXXXXXXXXXXXXXX     PIC X(0000).                                                            00/00/00
   4100                10  XXXXXXXXXXXXXXXX     PIC X(0000).                                                            00/00/00
   5200  **********************************************************************                                         00/00/00
  10900                                                                                                                 00/00/00
                                  * * * *  E N D  O F  S O U R C E  * * * *


Output from XTRAN:

       PROCESS XXXXX
       IDENTIFICATION DIVISION.
       PROGRAM-ID.   XXXXXXX.
       AUTHOR.  XXXXXXXXXXXXX.
       DATE-WRITTEN. 00/00/00.
 **********************************************************************
       ENVIRONMENT DIVISION.
       CONFIGURATION SECTION.
       SOURCE-COMPUTER. IBM-AS400.
       OBJECT-COMPUTER. IBM-AS400.
       SPECIAL-NAMES. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                      XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                      XXXXXXXXXXXXXXXXXXXXXXXXXXXXX.
       INPUT-OUTPUT SECTION.
       FILE-CONTROL.

           SELECT XXXXXXXXXXX
               ASSIGN TO XXXXXXXXXXXXXXX
               ORGANIZATION IS INDEXED
               ACCESS IS DYNAMIC
               RECORD KEY IS XXXXXXXXXXXXXXXXXXXXXXXX
               FILE STATUS IS XXXXXXXXXXXXXX.

       DATA DIVISION.
       FILE SECTION.

       FD  XXXXXXXXXXX
           LABEL RECORDS ARE STANDARD.
       01  XXXXXXXXXXX.
           COPY XXXXXXXXXXXXXXX OF XXXXXX.

       WORKING-STORAGE SECTION.
      *--------------------------------------------------------------*
      *                  Xxxxxxxxxxxxxxxxxxxxxxxxxxx                 *
      *--------------------------------------------------------------*
       01  XXXXXXXXXXXXXXXXXXX.
           05  XXXXXXXXXXXXXX.
               10  XXXXXXXXXXXXXXXX     PIC X(00) VALUE 'XXXXXXX'.
               10  XXXXXXXXXXXXXXXXXX   PIC X(00) VALUE 'XXXXXX'.
                   88  XXXXXXXXXXXXXX   VALUE 'XXXXX'.
                   88  XXXXXXXXXXXXXXX  VALUE 'XXXXXX'.
               10  XXXXXXXXXXXXXXXX     PIC X(0000).
               10  XXXXXXXXXXXXXXXX     PIC X(0000).
 **********************************************************************