Standard way to remove spaces from input in cobol? - cobol

Question

I'm just learning COBOL; I'm writing a program that simply echos back user input. I have defined a variable as:
User-Input PIC X(30).
Later when I ACCEPT User-Input, then DISPLAY User-Input " plus some extra text", it has a bunch of spaces to fill the 30 characters. Is there a standard way (like Ruby's str.strip!) to remove the extra spaces?

Answer 1

One would hope for a more elegant way of simply trimming text strings
but this is pretty much the standard solution... The trimming part
is done in the SHOW-TEXT paragraph.
*************************************
* TRIM A STRING... THE HARD WAY...
*************************************
IDENTIFICATION DIVISION.
PROGRAM-ID. TESTX.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 USER-INPUT PIC X(30).
01 I PIC S9(4) BINARY.
PROCEDURE DIVISION.
MOVE SPACES TO USER-INPUT
PERFORM SHOW-TEXT
MOVE ' A B C' TO USER-INPUT
PERFORM SHOW-TEXT
MOVE 'USE ALL 30 CHARACTERS -------X' TO USER-INPUT
PERFORM SHOW-TEXT
GOBACK
.
SHOW-TEXT.
PERFORM VARYING I FROM LENGTH OF USER-INPUT BY -1
UNTIL I LESS THAN 1 OR USER-INPUT(I:1) NOT = ' '
END-PERFORM
IF I > ZERO
DISPLAY USER-INPUT(1:I) '# OTHER STUFF'
ELSE
DISPLAY '# OTHER STUFF'
END-IF
.
Produces the following output:
# OTHER STUFF
A B C# OTHER STUFF
USE ALL 30 CHARACTERS -------X# OTHER STUFF
Note that the PERFORM VARYING statement relies on the left to
right evaluation of the UNTIL clause to avoid out-of-bounds
subscripting on USER-INPUT in the case where it contains only
blank spaces.

Answer 2

Use OpenCOBOL 1.1 or greater.
Identification division.
Program-id. 'trimtest'.
*> Compile:
*> cobc -x -free -ffunctions-all TrimTest.cbl
*>
Data division.
Working-Storage Section.
1 myBigStr Pic X(32768) Value Spaces.
Procedure Division.
Display "Enter Something? " With no advancing.
Accept myBigStr.
Display "[" Trim(myBigStr) "]".
Goback.
The trim function also has the options; Leading or Trailing.
cobc -h formore info.

Answer 3

Here's a solution if you work on OpenVMS:
01 WS-STRING-LENGTH PIC S9(04) COMP.
CALL "STR$TRIM" USING BY DESCRIPTOR user_output,
user_input,
BY REFERENCE WS-STRING-LENGTH.

Answer 4

a more general solution:
01 length pic 99.
perform varying length from 1 by 1
until length > 30 or user-input[length] = space
end-perform.
if length > 30
display user-input 'plus some extra text'
else
display user-input[1:length] 'plus some extra text'
end-if.
untested, I don't have a compiler at hand at the moment

Answer 5

There are three ways you can do this.
Use the COBOL functions to determine the string's "length". This is a mix of a couple functions. This is my preferred method, but requires declaring extra variables.
Write your own function to get the "length".
Use knowledge of a "terminating" string. You have to know what key characters indicates an end-of-string, like three spaces or a low-value character.
This example code demonstrates all three.
IDENTIFICATION DIVISION.
PROGRAM-ID. TESTPROG.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 ONE-A PIC X(20) VALUE 'RALPH WIGGAM'.
01 ONE-A-TLY PIC 9(02) VALUE ZERO.
01 ONE-A-LEN PIC 9(02) VALUE ZERO.
01 ONE-B PIC X(20) VALUE 'LIKES LEARNDING'.
01 ONE-B-TLY PIC 9(02) VALUE ZERO.
01 ONE-B-LEN PIC 9(02) VALUE ZERO.
01 TWO-A PIC X(20) VALUE 'RALPH WIGGAM'.
01 TWO-A-LEN PIC 9(02) VALUE ZERO.
01 TWO-B PIC X(20) VALUE 'LIKES LEARNDING'.
01 TWO-B-LEN PIC 9(02) VALUE ZERO.
01 THREE-A PIC X(20) VALUE 'RALPH WIGGAM'.
01 THREE-B PIC X(20) VALUE 'LIKES LEARNDING'.
01 THREE-C PIC X(80) VALUE SPACES.
PROCEDURE DIVISION.
DISPLAY ' -- METHOD ONE -- '
INSPECT FUNCTION REVERSE(ONE-A)
TALLYING ONE-A-TLY FOR LEADING SPACES.
SUBTRACT ONE-A-TLY FROM LENGTH OF ONE-A GIVING ONE-A-LEN.
INSPECT FUNCTION REVERSE(ONE-B)
TALLYING ONE-B-TLY FOR LEADING SPACES.
SUBTRACT ONE-B-TLY FROM LENGTH OF ONE-A GIVING ONE-B-LEN.
DISPLAY ONE-A(1:ONE-A-LEN)
' ' ONE-B(1:ONE-B-LEN)
'.'.
DISPLAY ' -- METHOD TWO -- '
PERFORM VARYING TWO-A-LEN FROM LENGTH OF TWO-A BY -1
UNTIL TWO-A-LEN < 1 OR TWO-A(TWO-A-LEN:1) > SPACE
END-PERFORM.
PERFORM VARYING TWO-B-LEN FROM LENGTH OF TWO-B BY -1
UNTIL TWO-B-LEN < 1 OR TWO-B(TWO-B-LEN:1) > SPACE
END-PERFORM.
DISPLAY TWO-A(1:TWO-A-LEN)
' ' TWO-B(1:TWO-B-LEN)
'.'.
DISPLAY ' -- METHOD THREE, NAIVE -- '
* DELIMITING BY JUST ANY SPACES ISN'T GOOD ENOUGH.
STRING THREE-A DELIMITED BY SPACES
' ' DELIMITED BY SIZE
THREE-B DELIMITED BY SPACES
'.' DELIMITED BY SIZE
INTO THREE-C.
DISPLAY THREE-C.
DISPLAY ' -- METHOD THREE, OK -- '
STRING THREE-A DELIMITED BY ' '
' ' DELIMITED BY SIZE
THREE-B DELIMITED BY ' '
'.' DELIMITED BY SIZE
INTO THREE-C.
DISPLAY THREE-C.
EXIT-PROG.
STOP RUN.
and the output looks like this:
-- METHOD ONE --
RALPH WIGGAM LIKES LEARNDING.
-- METHOD TWO --
RALPH WIGGAM LIKES LEARNDING.
-- METHOD THREE, NAIVE --
RALPH LIKES.
-- METHOD THREE, OK --
RALPH WIGGAM LIKES LEARNDING.