Forum Discussion
jakk127_200290
Nimbostratus
NimbostratusTrying to understand using square braces vs parenthesis in iRules
Hello,
I have an written the following iRule
when HTTP_REQUEST {
set user_agent [string tolower [HTTP::header User-Agent]]
if { not ($user_agent contains "windows nt 5.1")} {
vi...
jakk127_200290Nimbostratus
NimbostratusHey. I looked at that article but it did not answer my questions. It gave a use case for parenthesis but did not explain how they were used
DEJThe only other use I can think of is to override order of operations. The other uses I saw listed - negative comparison, regex, and arrays.- jakk127_200290Ok, well that follows what I was finding, which is why I am confused. I would think that a statement like if { not [$user_agent contains "windows nt 5.1"]} would mean that the command '$user_agent contains "windows nt 5.1"' would be executed first, which would result in a boolean, which would be negated by the not operator, which would then be passed to 'if'. However, I must not be understanding something correctly as that was causing the tcp reset, and only when I replaced the [ with ( did the irule operate correctly. I am even more confused because the first way, with the braces, compiled and did not give me any errors
