How to read the syntax diagrams
This topic explains BMC conventions for syntax statements and syntax diagrams.
Syntax statements
A sample statement follows:
COMMAND KEYWORD1 [KEYWORD2 | KEYWORD3] KEYWORD4={YES | NO} fileName...
The following table explains conventions for syntax statements and provides examples:
Convention | Example |
|---|---|
Items in italic type or angle brackets represent variables that you must replace with a name or value. If a variable is represented by two or more words, initial capitals distinguish the second and subsequent words. | alias <alias> databaseDirectory <serverHostName> |
Brackets indicate optional items. Do not type the brackets when you enter the option. A comma means that you can choose one or more of the listed options. You must use a comma to separate the options if you choose more than one option. | [tableName, columnName, field][-full, -incremental, -level] |
Braces indicate that at least one of the enclosed items is required. Do not type the braces when you enter the item. | {DBDName | tableName}UNLOAD device={disk | tape, fileName} {-a | -c} |
A vertical bar means that you can choose only one of the listed items. In the example, you would choose either commit or cancel. | {commit | cancel} |
An ellipsis indicates that you can repeat the previous item or items as many times as necessary. | columnName... |
Syntax diagrams
The following figure shows the standard format for syntax diagrams:
The following example illustrates the syntax for a hypothetical DELETE statement. The FROM keyword, alias variable, and WHERE clause appear below the main command line because they are optional. In contrast, the tableName variable appears on the command line because the table name is required. If the statement includes a WHERE clause, the clause must contain a search condition or a CURRENT OF clause. (The searchCondition variable appears on the main line for the WHERE clause, indicating that this choice is required.)
The following guidelines provide additional information about syntax diagrams:
- Read diagrams from left to right and from top to bottom.
- A recursive (left-pointing) arrow above a stack indicates that you can choose more than one item in the stack.
- An underlined item is a default option.
- If a diagram shows punctuation marks, parentheses, or similar symbols, you must enter them as part of the syntax.
- In general, IBM commands, keywords, clauses, and data types are displayed in uppercase letters. However, if an item can be shortened, the minimum required portion might be shown in uppercase letters, with the remainder in lowercase (for example, CANcel).
- The following conventions apply to variables in syntax diagrams:
- Variables are typically displayed in lowercase letters and are always italicized.
- If a variable is represented by two or more words, initial capitals distinguish the second and subsequent words (for example, databaseName).
Legacy diagrams
Some syntax diagrams in this documentation use the following conventions:
Fragments
If a diagram contains syntax that is too long, too complex, or too repetitious to show in-line then the fragment is separated from the main syntax diagram as shown as follows:
Keywords and variable operands
Keywords are shown in bold-faced upper case or mixed upper and lower case. You must spell the keyword as shown (in your choice of upper, lower, or mixed case). You might abbreviate the keyword by using only the letters shown in upper case, or the letters shown in upper case and any leading subset of the characters shown in lower case. Using the example shown here, you could code OPT, OPTION, Optio, or options (but not OP or OPTS).
User-specifiable variable items are shown in lower case italic.
Parameters
Required parameters are shown on the main path. Optional parameters are shown here in the main path. Any default parameter is shown above the main path. Choices are stacked bracketed by vertical lines.
Selecting more than one option
When you specify multiple items, or specify one item more than once, it is indicated by an arrow returning to the left above the items.
Special characters and blanks
When a comma, equal sign, parenthesis or blank is shown in the diagram then you must code it as shown. For the instance here, you must code the parentheses, commas, and spaces, such as PARM(A,B X,Y).
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