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 | ||
|---|---|---|
| ||
./daffodil --debug 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. Below is the list of commands and their descriptions.
Commands
...
break...
<element_id>...
Create a breakpoint, causing the debugger to stop when the element
with the <element_id> name is created.
...
break element.foo...
clear...
clear...
condition...
<breakpoint_id> <dfdl_expression>...
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.
...
condition 1 dfdl:occursIndex() = 3...
continue...
Continue parsing the input data until a breakpoint is encountered. At
which point, pause parsing and display a debugger console to the user.
...
continue...
delete...
<type> <id>...
Remove a breakpoint or display. Valid values for <type> are "breakpoint"
and "display".
...
delete breakpoint 1delete display 1...
disable...
<type> <id>...
Disable a breakpoint or display. Valid values for <type> are "breakpoint"
and "display".
...
disable breakpoint 1disable display 1...
display...
<debugger command>...
Execute a debugger command every time a debugger console is displayed
to the user.
...
display info infoset...
enable...
<type> <id>...
Enable a breakpoint or display. Valid values for <type> are "breakpoint"
and "display".
...
enable breakpoint 1enable display 1...
eval...
[type] <dfdl_expression>...
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."
...
eval number dfdl:occursIndex()...
help...
[<command>]...
Display help. If a command is given, display help information specific
to that command and its subcommands.
...
helphelp info...
info...
<item>......
Print various pieces of internal information to the console. The valid items are:
| item | description |
|---|---|
| arrayIndex | current index of the element in an array |
| bitLimit | current bit limit |
| bitPosition | current bit position in the data |
| breakpoints | list of breakpoints |
| childIndex | current child index |
| data | input data |
| discriminator | whether or not a discriminator is set |
| displays | list of displays |
| infoset | current infoset |
| occursCount | occurs count |
| path | path in the schema, using schema component designator |
...
info data infoset...
quit...
quit...
set...
<setting> <value>...
Change a debugger setting. The settings are:
| Setting | Type | Description |
|---|---|---|
| dataLength | integer | number of bytes to display when displaying input data. If negative, display all input data. |
| infosetLines | integer | number of lines of the infoset to display. This displays the last X number of lines. If negative, display the entire infoset |
| removeHidden | boolean | whether or not to remove hidden elements (via dfdl:hiddenGroupRef) when displaying the infoset |
| wrapLength | integer | number of character at which to wrap data or infoset when printed to the console |
...
set dataLength -1set wrapLength 50set removeHidden true...
step...
step...
undisplay...
<display_id>...