Use Shellcheck to resolve violations code in Shell Script

[Rahulkhinchi03]

ShellCheck is an open-source static analysis tool that automatically finds bugs in your shell scripts. (https://github.com/koalaman/shellcheck)

For more information on Code: https://gist.github.com/nicerobot/53cee11ee0abbdc997661e65b348f375#file-_shellcheck-md

./.ci/*sh has all the shell scripts files and we have all the disabled violations at the .shellcheckrc file.
We are currently invoking spellcheck through Terminal (You can download (https://github.com/koalaman/shellcheck#installing) it through apt or similar package managers on local). We have integrated Shellcheck with GitHub action https://github.com/checkstyle/checkstyle/actions/workflows/shellcheck.yml

TO-DO:

checkstyle/.shellcheckrc

Lines 1 to 3 in 1ef8fdd

	# until https://github.com/checkstyle/checkstyle/issues/11637
	disable=SC2086 # (info): Double quote to prevent globbing and word splitting.

• Pick a suppression (single suppression fix in single Pull Request) To allocate a suppression update for you please make comment in the issue "I am on "SCxxxxSuppression"
• Remove Your Selected Suppression from the .shellcheckrc file.
• Run shellcheck through Terminal and See Errors
• Fix the Errors and make a PR.

LIST OF SUPPRESSIONS:

• SC2086 # (info): Double quote to prevent globbing and word splitting.
• SC2006 # (style): Use $(...) notation instead of legacy backticks ....
• SC2046 # (warning): Quote this to prevent word splitting.
• SC2207 # (warning): Prefer mapfile or read -a to split command output.
• SC2002 # (style): Useless cat. Consider 'cmd < file | ..' or 'cmd file | ..' instead.
• SC2061 # (warning): Quote the parameter to -name so the shell won't interpret it.
• SC2035 # (info): Use ./glob or -- glob so names with dashes won't become options.
• SC2236 # (style): Use -n instead of ! -z.
• SC2016 # (info): Expressions don't expand in single quotes, use double quotes for that.
• SC2185 # (info): Some finds don't have a default path. Specify '.' explicitly.
• SC2155 # (warning): Declare and assign separately to avoid masking return values.
• SC2071 # (error): > is for string comparisons. Use -gt instead.
• SC2034 # (warning): RUN_JOB appears unused. Verify use (or export if used externally).
• SC2216 # (warning): Piping to 'true', a command that doesn't read stdin.
• SC2013 # (info): To read lines rather than words, pipe/redirect to a 'while read' loop.
• SC2206 # (warning): Quote to prevent word splitting/globbing.
• SC2143 # (style): Use grep -q instead of comparing output with [ -n .. ].
• SC2004 # (style): $/${} is unnecessary on arithmetic variables.
• SC2087 # (warning): Quote 'EOF' to make here document expansions happen on the server-side.
• SC2102 # (info): Ranges can only match single chars (mentioned due to duplicates).
• SC2242 # (error): Can only exit with status 0-255.
• SC2115 # (warning): Use "${var:?}" to ensure this never expands to /* .
• SC2128 # (warning): Expanding an array without an index only gives the first element.
• SC2063 # (warning): Grep uses regex, but this looks like a glob.
• SC2126 # (style): Consider using grep -c instead of grep|wc -l.
• SC2088 # (warning): Tilde does not expand in quotes. Use $HOME.
• SC2005 # (style): Useless echo? Instead of 'echo $(cmd)', just use 'cmd'.
• SC2015 # (info): Note that A && B || C is not if-then-else. C may run when A is true.
• SC2026 # (info): This word is outside of quotes.
• SC2269 # (info): This variable is assigned to itself, so the assignment does nothing.
• SC2230: which is non-standard. Use builtin 'command -v' instead.
• SC2153: Possible Misspelling: MYVARIABLE may not be assigned, but MY_VARIABLE is.
• SC1004: This backslash+linefeed is literal. Break outside single quotes if you want to break the line.

Example of expected update with removal of suppression: 5ea26d6

[Rahulkhinchi03]

@romani @rnveach @nick-mancuso The wercker.sh violations are excluded in the issue as #11564

[romani]

@Rahulkhinchi03, please send single PR to resolve all violations of single rule to show example how to fix violations and remove suppression.

[Rahulkhinchi03]

@romani @nick-mancuso @rnveach
Before the Project gets started, Should I resolve all the shell code errors in the release.sh file by creating PR?

[romani]

Yes, but Better to slice a work by rules to let us activate rule and make sure nobody will introduce problems again.

[Rahulkhinchi03]

Sure, I can see that release.sh has error codes: SC2086, SC2006

[stoyanK7]

I am on SC2269 and SC2046

[Rahulkhinchi03]

@stoyanK7 That's really great!
Please make different PRs for both the ERROR CODES.

[ThatSneakyCoder]

I'm on SC2005

[ThatSneakyCoder]

@romani

Kindly update the checklist. Shellcheck SC2006 is already resolved but, not checked in the checklist(#11637....)

[ThatSneakyCoder]

I'm on SC2002, SC2016, SC2061.