Allow escaping dash (`-`) in CLI command parsing to prevent syntax errors

[pnxtm]

Description:

We are adding a new CLI command that includes a dash (-) in its syntax, but the parser incorrectly interprets it as a range and throws an error.

Example Command:

show interface range (1-10) - (1-10)

This should be valid, but it results in the following error:

cmd_yyerror: FATAL parse error: syntax error, unexpected invalid token, expecting end of file
cmd_yyerror: 1:52-53 of this command definition:
cmd_yyerror: | show interface range (1-10) - (1-10)
cmd_yyerror: |                             ^

Issue:

• The dash (-) is treated as a range separator, causing conflicts when used as a literal character.
• There seems to be no clear way to escape it so that it is recognized as a normal character.

Expected Behavior:

There should be a way to allow - as a valid character in command syntax without interfering with range parsing.

Request:

Is there a recommended way to handle this in FRR’s command parsing system? A possible solution could be supporting an escape sequence (e.g., \-) or modifying the parser to differentiate between a range operator and a literal dash.

Any guidance on resolving this would be appreciated.

[ton31337]

Why just not show interface range (1-10) (1-10)?

[Jafaral]

Would be nice to know what show interface range (1-10) - (1-10) actually does or means. It doesn't make sense out of context. Maybe there are better ways if we know the context.

[pnxtm]

Would be nice to know what show interface range (1-10) - (1-10) actually does or means. It doesn't make sense out of context. Maybe there are better ways if we know the context.

@Jafaral, When a command like show interface range (1-10) - (1-10) is defined, we can run the command like this:

config# show interface range 1-10

which means displaying configurations for interfaces starting from port 1 to port 10.

Why just not show interface range (1-10) (1-10)?

@ton31337, Your solution is a good suggestion too, but a range specifier would be more user-friendly.

Regardless of the dash issue, we also need to be able to use the comma character, which results in the same error. For example, we want to have the following command:

show interface range 1-10,15,20  

Surely, in this case, your method is not practical.

[donaldsharp]

Can you show us your cli function? (At least the DEF.... part ). Arbitrary strings are supported. See something like this:

eva# conf 
eva(config)# int enp13s0
eva(config-if)# description 1-10,15,20
eva(config-if)# end
eva# show run
<snip>
!
interface enp13s0
 description 1-10,15,20
exit
!
<snip>

Obviously you'll need to write something that can interpret this. There are examples of that too. See the bgp ASN regex code. The community handlers probably do it too

[pnxtm]

@donaldsharp , thanks for your comment. Sorry, it seems that simplifying my question misled the request. I want to implement this command:

DEFPY (vtysh_interface_range,
       vtysh_interface_range_cmd,
       "interface range "
       "<"
       		"port (1-10)|port (1-10) - (1-10)|"
		"vlan (1-4094)|vlan (1-4094) - (1-4094)|"
		"gport (1-5)|gport (1-5) - (1-5)"
       ">  [,",
       "<"
       		"port (1-10)|port (1-10) - (1-10)|"
		"vlan (1-4094)|vlan (1-4094) - (1-4094)|"
		"gport (1-5)|gport (1-5) - (1-5)"
       ">  [,",
       ...
) ...

The user can enter 8 combinations (I only showed 2 for simplicity) of ports, gports, and VLAN interface combinations. It can't be implemented as a WORD (like the description in the interface node).

[github-actions]

This issue is stale because it has been open 180 days with no activity. Comment or remove the autoclose label in order to avoid having this issue closed.

[frrbot]

This issue will be automatically closed in the specified period unless there is further activity.