The Daffodil Command Line Interface (CLI) comes with a built-in interactive debugger that pauses parsing and allows for user inspection of the parsing state. To start Daffodil in debugger mode, provide the global --debug/-d option, for example:
Code Block | ||
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./daffodil --debug [file] parse --schema schema.dfdl.xsd input.dat |
Enabling the debugger displays a (debug)
prompt, at which point various commands can be entered to control parsing and inspect Daffodil state.
Note that you can optionally provide a file to the --debug
option. Each line in the file will be provided to the debugger as if it was type by the user.
Below is the list of commands and their descriptions.
Commands
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break
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<element_id>
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Create a breakpoint, causing the debugger to stop when the element with the <element_id> name is created.
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break element.foo
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clear
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clear
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Continue parsing the input data until parsing is complete. All breakpoints are ignored.
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condition
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<breakpoint_id> <dfdl_expression>
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Set a condition on a specified breakpoint. When a breakpoint is encountered, the debugger only pauses if the DFDL expression evaluates to true. If the result of the DFDL expressions is not a boolean value, it is treated as false.
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condition 1 dfdl:occursIndex() = 3
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continue
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Continue parsing the input data until a breakpoint is encountered. At which point, pause parsing and display a debugger console to the user.
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continue
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delete
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<type> <id>
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Remove a breakpoint or display. Valid values for <type> are "breakpoint" and "display".
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delete breakpoint 1
delete display 1
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disable
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<type> <id>
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Disable a breakpoint or display. Valid values for <type> are "breakpoint" and "display".
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disable breakpoint 1
disable display 1
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display
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<debugger command>
...
Execute a debugger command every time a debugger console is displayed to the user.
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display info infoset
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enable
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<type> <id>
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Enable a breakpoint or display. Valid values for <type> are "breakpoint" and "display".
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enable breakpoint 1
enable display 1
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eval
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[type] <dfdl_expression>
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Evaluate a DFDL expression. The [type] argument determines how to display the result of the dfdl_expression. The value of [type] may be "string", "number", "boolean", or "node". If [type] is not given, then "node" is assumed."
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eval number dfdl:occursIndex()
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help
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[command]
...
Display help. If a command is given, display help information specific to that command and its subcommands.
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help
help info
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Display the history of commands. If an argument is given, write the history to the specified file rather then printing it to the screen.
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history
history out.txt
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info
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<item>...
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Print internal information to the console. <item> can be specified multiple times to display multiple pieces of information.
The valid items are:
Item | Short Item | Description |
---|---|---|
arrayIndex |
| display the current array limit |
bitLimit | bl | display the current bit limit |
bitPosition | bp | display the current bit position |
breakpoints | b | display the list of breakpoints |
childIndex | ci | display the child index |
data | d | display the input data |
diff | diff | display the differences from the previous state |
discriminator | dis | display whether or not a discriminator is set |
displays | di | display the current 'display' expressions |
groupIndex | gi | display the current group index |
infoset | i | display the current infoset |
occursCount | oc | display the current occurs count |
parser | p | display the current Daffodil parser |
path | path | display the schema component designator |
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info data infoset
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quit
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quit
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set
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<setting> <value>
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Change a debugger setting. The valid settings are:
Setting | Value Type | Description | Default |
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breakOnFailure | boolean | Set whether or the debugger should break on failures. If set to false | false |
breakOnlyOnCreation | boolean | Set whether or not breakpoints should only be evaluated on element creation. <value> must be either true/false or 1/0. If true, breakpoints only stop on element creation. If false, breakpoints stop anytime a parser interacts with an element. | true |
dataLength | integer | Set the number of bytes to display when displaying input data. If negative, display all input data. This only affects the 'info data' command. | 70 |
infosetLines | integer | Set the maximum number of lines to display when displaying the infoset. This only affects the 'info infoset' command. This shows the last <value> lines of the infoset. If <value> is less than or equal to zero, the entire infoset is printed. | -1 |
removeHidden | boolean | Set whether or not hidden elements (e.g through the use of | false |
wrapLength | integer | Set the number of characters at which point output wraps. This only | 80 |
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set dataLength -1
set wrapLength 50
set removeHidden true
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step
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s
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Perform a single parse action, pause parsing, and display a debugger prompt.
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step
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trace
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t
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Continue parsing the input data until a breakpoint is encountered, while running display commands after every parse step. When a breakpoint is encountered, pause parsing and display a debugger console to the user.
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