9.7. Parsing Instructions Examples

All examples in this section parse source strings into words.

ARG

Example 9.18. ARG with source string named in Rexx program invocation

/* ARG with source string named in Rexx program invocation       */
/*  Program name is PALETTE.  Specify 2 primary colors (yellow,  */
/*   red, blue) on call.   Assume call is: palette red blue      */
arg var1 var2                /* Assigns: var1="RED"; var2="BLUE" */
If var1<>"RED" & var1<>"YELLOW" & var1<>"BLUE" then signal err
If var2<>"RED" & var2<>"YELLOW" & var2<>"BLUE" then signal err
total=length(var1)+length(var2)
SELECT;
  When total=7 then new="purple"
  When total=9 then new="orange"
  When total=10 then new="green"
Otherwise new=var1                         /* entered duplicates */
END
Say new; exit                              /* Displays: "purple" */

Err:
say 'Input error--color is not "red" or "blue" or "yellow"'; exit

ARG converts alphabetic characters to uppercase before parsing. An example of ARG with the arguments in the CALL to a subroutine is in Section 9.8.1, “Parsing Several Strings”.

PARSE ARG is similar to ARG except that PARSE ARG does not convert alphabetic characters to uppercase before parsing.

PARSE LINEIN

Example 9.19. PARSE LINEIN

parse linein "a=" num1 "c=" num2     /* Assume: 8 and 9          */
sum=num1+num2                        /* Enter: a=8 b=9 as input  */
say sum                              /*  Displays: "17"          */

PARSE PULL

Example 9.20. PARSE PULL

PUSH "80 7"                /* Puts data on queue                 */
parse pull fourscore seven /* Assigns: fourscore="80"; seven="7" */
SAY fourscore+seven        /* Displays: "87"                     */

PARSE SOURCE

Example 9.21. PARSE SOURCE

parse source sysname .
Say sysname                         /* Possibly Displays:        */
                                    /* "Windows"                 */

PARSE VAR examples are throughout the chapter, starting with Chapter 9, Parsing.

PARSE VERSION

Example 9.22. PARSE VERSION

parse version . level .
say level                /* Displays: "6.02" */

PULL is similar to PARSE PULL except that PULL converts alphabetic characters to uppercase before parsing.