Shorter if syntax

[qiufeihai]

[[ 1 == 1 ]] && { command exit 1 } || { this command will exec }
how to avoid???

[linux478]

I do not understand what you are trying to tell.

[Skizo4]

Thank you very much.

…

On Thu, Dec 9, 2021, 4:04 PM Michael Phillips ***@***.***> wrote: I do not understand what you are trying to tell. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#112 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AV7BMB2TZLLR2FZW4FR3FHTUQDHPZANCNFSM4WTEZRYA> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.

[TedHartDavis]

I am so confused by this.

[TinCanTech]

Missing terminating quote, bracket or keyword

[ghost]

I'm sure you found a solution by now, but just in-case you didn't:

You have two syntax errors, because you're missing the ; before the final } in each command group. The typical way to group commands (without a subshell) is { like this; }. Grouping a single command is redundant.

The COMMAND && COMMAND || COMMAND approach does not equate to if, then, else, although it can work in a similar way. Likewise, COMMAND || COMMAND && COMMAND does not equate to the opposite.

Why? Because what the first example actually means is that the 2nd command will execute if the 1st one succeeds, or the 3rd command will execute if the 1st command fails. However, if the 1st command succeeds and the 2nd command also happens to fail, then all three commands wind up being executed regardless. Understanding this is very important, as you can wind up doing some pretty stupid stuff otherwise.

Furthermore, the exit statuses are not contained, unlike with an if statement, which is pretty important if it's the last command in a script or you're checking $?.

[YasserKa]

"Shorter if syntax" should be removed to stop spreading miss-information.

More context can be found here: http://mywiki.wooledge.org/BashPitfalls#cmd1_.26.26_cmd2_.7C.7C_cmd3

[ghost]

Agreed, it's misleading and incorrect. I see what the author meant, but it's important to be accurate when it comes to complicated matters like programming, IMO. Logical operators can be used similar to an if statement, in a simple way, but it's not technically or actually a replacement or "shorter" version.