Incorrect parsing of input when "!=" operator is used

[prakashsurya]

When using the != operator with the filter or pyfilter commands, the lexer will incorrectly split that operator into two tokens, instead of grouping the two characters into a single token. Specifically, it will split != into ! and = tokens, when it should return a single != token.

Here's a concrete example:

> spa | filter obj.spa_name != "rpool" | pp

In this example, the expectation is for the following to occur:

1. spa is called without any arguments
2. filter is called with arguments: obj.spa_name != "rpool"
3. pp is called without any arguments

Unfortunately, due to the bug in the lexer, this does not happen. What does happen is the following:

1. spa is called without any arguments
2. filter is called with arguments: obj.spa_name
3. A suprocess is created to execute: = "rpool" | pp

This is because != is split into the tokens ! and =, and then we interpret the ! special, as it is used to denote piping into a subprocess rather than piping into an SDB command.

[sdimitro]

Issued #81

[sdimitro]

With the new parser introduced here -> #219

This can be now closed as we just decided to add quotes around the !=:

sdb> spa | filter 'obj.spa_name != "data"' | spa
ADDR               NAME
------------------------------------------------------------
0xffff8f951288c000 rpool