Differences

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--- openvms:openvms-cheatsheet [2023/07/01 07:54] – dodger
+++ openvms:openvms-cheatsheet [2023/07/01 08:10] (current) – dodger
@@ Line 50: / Line 50: @@
 ===== Aliases through symbols =====
-Create an alias ''EDT' with a frequently used command:
+Create an alias ''EDT'' with a frequently used command:
 <code DCL>
 EDT :== EDIT/EDT/COMMAND=SYS$LOGIN:EDTINI.DDT
@@ Line 70: / Line 70: @@
 $ SHOW SYMBOL APPLES
   APPLES = 10    Hex = 0000000A    Octal = 00000000012
+$ APPLES = 2 * (4+5)
+$ SHOW SYMBOL APPLES
+  APPLES = 18    Hex ...
+$ ORANGES = 15
+$ TOTAL_FRUIT = APPLES + ORANGES
+$ SHOW SYMBOL TOTAL_FRUIT
+  TOTAL_FRUIT = 33
 </code>
+=== List of operations ===
+^ Operation ^
+| ''+'' |
+| ''-'' |
+| ''*'' |
+| ''/'' |
+==== String operations ====
+<code DCL>
+$ APPLES = "Apples"
+$ SHOW SYMBOL APPLES
+  APPLES = "Apples"
+$ FRUIT = "Oranges and " + APPLES
+$ SHOW SYMBOL FRUIT
+  FRUIT = "Oranges and Apples"
+</code>
+==== Using subshells in commands ====
+Sub-shell is invoqued with ''2 SINGLE QUOTES+VARIABLE+1 SINGLE QUOTE'', for examples:
+<code DCL>
+$ FILETYPE = "login.com"
+$ TYPEIT = "TYPE ''filename'"
+$ SHOW SYMBOL TYPEIT
+  "TYPE login.com"
+</code>
+<WRAP center round tip 60%>
+Take care with string usage '':=''
+</WRAP>
+What works and what not (as a sub-shell):
+  * Works:
+<code DCL>
+$ FILETYPE := "login.com"
+$ TYPEIT := "TYPE ''filename'"
+$ SHOW SYMBOL TYPEIT
+  "TYPE login.com"
+</code>
+  * DON'T Work (as a literal)
+<code DCL>
+$ FILETYPE := "login.com"
+$ TYPEIT := "TYPE" +  filename
+$ SHOW SYMBOL TYPEIT
+  "TYPE FILENAME"
+</code>
+<WRAP center round tip 60%>
+In the other hand, without forcing string assignment
+</WRAP>
+Both are assigned as a variable:
+<code DCL>
+$ FILETYPE = "login.com"
+$ TYPEIT = "TYPE ''filename'"
+$ SHOW SYMBOL TYPEIT
+  "TYPE login.com"
+</code>
+<code DCL>
+$ FILETYPE = "login.com"
+$ TYPEIT = "TYPE" +  filename
+$ SHOW SYMBOL TYPEIT
+  "TYPE login.com"
+</code>
 ====== Startup ======