From cac27831e1fd29f27821133b6eaebb30df70550a Mon Sep 17 00:00:00 2001 From: PXW865 <108454503+PXW865@users.noreply.github.com> Date: Tue, 5 Jul 2022 17:35:07 +0530 Subject: [PATCH] Updated SC2154 (markdown) --- SC2154.md | 69 +++++-------------------------------------------------- 1 file changed, 6 insertions(+), 63 deletions(-) diff --git a/SC2154.md b/SC2154.md index 4492210..19bff74 100644 --- a/SC2154.md +++ b/SC2154.md @@ -1,63 +1,6 @@ -## var is referenced but not assigned. - -### Problematic code: - -```sh -var=name -n=42 -echo "$var_$n.jpg" # overextended -``` - -or - -```sh -target="world" -echo "hello $tagret" # misspelled -``` - -or - -```sh -echo "Result: ${mycmd -a myfile}" # trying to execute commands -``` - -### Correct code: - -```sh -var=name -n=42 -echo "${var}_${n}.jpg" -``` - -or - -```sh -target="world" -echo "hello $target" -``` - -or - -```sh -echo "Result: $(mycmd -a myfile)" -``` - -### Rationale: - -ShellCheck has noticed that you reference a variable that is not assigned. Double check that the variable is indeed assigned, and that the name is not misspelled. - -Note: This message only triggers for variables with lowercase characters in their name (`foo` and `kFOO` but not `FOO`) due to the standard convention of using lowercase variable names for unexported, local variables. - -### Exceptions: - -ShellCheck intentionally does not attempt to figure out runtime or dynamic assignments like with `source "$(date +%F).sh"` or `eval var=value`. See [[SC2034]] for an extended discussion of why this is the case. - -If you know for a fact that the variable is set, you can use `${var:?}` to fail if the variable is unset (or empty), initialize it to a default value if uninitialized with `: "${var:=}"`, or explicitly initialize/declare it with `var=""` or `declare var`. You can also disable the message with a [[directive]]. - ---- - -## Read more: - -POSIX - Parameter expansion: -* https://stackoverflow.com/a/16753536/2309247 -* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_02 \ No newline at end of file +RUN \ + export http_proxy=${http_proxy}; \ + export https_proxy=${https_proxy}; \ + dnf -y upgrade; \ + dnf -y install libXext libXrender libXtst xorg-x11-server-Xvfb fontconfig unzip sudo telnet; \ + dnf -y clean all \ No newline at end of file