False positive for SC1003

[ale5000-git]

For bugs

• Rule Id (if any, e.g. SC1000): SC1003
• My shellcheck version (shellcheck --version or "online"): online
• The rule's wiki page does not already cover this (e.g. https://shellcheck.net/wiki/SC2086)
• I tried on https://www.shellcheck.net/ and verified that this is still a problem on the latest commit

Here's a snippet or screenshot that shows the problem:

#!/bin/sh

echo 'abc test' | tr -d '\\'

Here's what shellcheck currently says:

echo 'abc test' | tr -d '\\'
                          ^-- SC1003 (info): Want to escape a single quote? echo 'This is how it'\''s done'.

Here's what I wanted or expected to see:

It is the backslash that is escaped, not the single quote.

The backslash in tr need to be escaped, otherwise bash say this:

echo 'abc test' | tr -d '\'
tr: warning: an unescaped backslash at end of string is not portable

[wileyhy]

Perhaps the Exceptions section in the wiki could be altered. https://www.shellcheck.net/wiki/SC1003 # As it is: "If you want your single-quoted string to end in a backslash, you can rewrite as 'string'\\ or ignore this warning." # Possible edit: "If you want for your single-quoted string to end in a backslash you can rewrite it as 'string'\\, or if you're quoting a single backslash such as in `tr -d '\\'`, you can ignore <https://www.shellcheck.net/wiki/ignore> this warning."

…

On Tue, Jul 30, 2024, 08:06 ale5000 ***@***.***> wrote: For bugs - Rule Id (if any, e.g. SC1000): SC1003 - My shellcheck version (shellcheck --version or "online"): online - The rule's wiki page does not already cover this (e.g. https://shellcheck.net/wiki/SC2086) - I tried on https://www.shellcheck.net/ and verified that this is still a problem on the latest commit Here's a snippet or screenshot that shows the problem: #!/bin/sh echo 'abc test' | tr -d '\\' Here's what shellcheck currently says: echo 'abc test' | tr -d '\' ^-- SC1003 (info): Want to escape a single quote? echo 'This is how it'''s done'. Here's what I wanted or expected to see: It is the backslash that is escaped, not the single quote. The backslash in tr need to be escaped, otherwise bash say this: echo 'abc test' | tr -d '\' tr: warning: an unescaped backslash at end of string is not portable — Reply to this email directly, view it on GitHub <#3032>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AUF2F2YX5JDWTMJAQZQUQLTZO6TVZAVCNFSM6AAAAABLWSNLQOVHI2DSMVQWIX3LMV43ASLTON2WKOZSGQZTQMBWHEZDEMA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[brother]

@wileyhy a edit to the wiki is helpful indeed. but the case pointed out by OP is still valid I think.

Not sure it will be possible to handle all the permutations with a nice and easy information message though.
Decipher the actual intent is always hard. Did they forget the end single quote? And why was there two back slashes to begin with...

[ale5000-git]

And why was there two back slashes to begin with...

Because bash warn against this:
tr -d '\'
So it need to be this:
tr -d '\\'

[brother]

It was meant as a point in an imaginary internal reasoning leading up to that it's hard to understand the exact intent of code.
If they are missing a backslash, or added one too many. Or was missing a single quote. Or something completely different. People are hard.