diff options
| author | Eric Blake <eblake@redhat.com> | 2017-07-03 13:09:50 -0500 |
|---|---|---|
| committer | Max Reitz <mreitz@redhat.com> | 2017-07-11 17:45:00 +0200 |
| commit | b43671f80cda8d0f11dcb929ed76fbd680c29cec (patch) | |
| tree | e3828c333d14ebf29aecf05a4229e03be43e38b6 /qemu-options.hx | |
| parent | 6f55dfa4a418041033f6457e4635dc3cefe10cf7 (diff) | |
tests: Avoid non-portable 'echo -ARG'
POSIX says that backslashes in the arguments to 'echo', as well as
any use of 'echo -n' and 'echo -e', are non-portable; it recommends
people should favor 'printf' instead. This is definitely true where
we do not control which shell is running (such as in makefile snippets
or in documentation examples). But even for scripts where we
require bash (and therefore, where echo does what we want by default),
it is still possible to use 'shopt -s xpg_echo' to change bash's
behavior of echo. And setting a good example never hurts when we are
not sure if a snippet will be copied from a bash-only script to a
general shell script (although I don't change the use of non-portable
\e for ESC when we know the running shell is bash).
Replace 'echo -n "..."' with 'printf %s "..."', and 'echo -e "..."'
with 'printf %b "...\n"', with the optimization that the %s/%b
argument can be omitted if the string being printed is a strict
literal with no '%', '$', or '`' (we could technically also make
this optimization when there are $ or `` substitutions but where
we can prove their results will not be problematic, but proving
that such substitutions are safe makes the patch less trivial
compared to just being consistent).
In the qemu-iotests check script, fix unusual shell quoting
that would result in word-splitting if 'date' outputs a space.
In test 051, take an opportunity to shorten the line.
In test 068, get rid of a pointless second invocation of bash.
CC: qemu-trivial@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170703180950.9895-1-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'qemu-options.hx')
| -rw-r--r-- | qemu-options.hx | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/qemu-options.hx b/qemu-options.hx index 76b1c67737..2cc70b9cfc 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4374,7 +4374,7 @@ The simplest (insecure) usage is to provide the secret inline The simplest secure usage is to provide the secret via a file - # echo -n "letmein" > mypasswd.txt + # printf "letmein" > mypasswd.txt # $QEMU -object secret,id=sec0,file=mypasswd.txt,format=raw For greater security, AES-256-CBC should be used. To illustrate usage, @@ -4402,7 +4402,7 @@ telling openssl to base64 encode the result, but it could be left as raw bytes if desired. @example - # SECRET=$(echo -n "letmein" | + # SECRET=$(printf "letmein" | openssl enc -aes-256-cbc -a -K $KEY -iv $IV) @end example |