I want to define a macro that will replace some placeholders in makefiles and systemd unit files with the results of RPM variables (macros). However, I don't know if the way expansion works will make the following behave correctly:
%define repl_vars() (sed -e "s:\${LIBEXECDIR}:%{_libexecdir}:g" -e "s:\${LOCALSTATEDIR}:%{_localstatedir}:g" -e "s:\${SYSCONFIGDIR}:%{_sysconfdir}:g" %{1} > %{1}.new && mv %{1}.new %{1})
Where the capitalized ${...} are the placeholders to be replaced with the actual paths held by the standard RPM variables (macros).
Also, escaping the $ of the placeholders with \ works in Bash and stuff I put in the %install section of the SPEC file, but is that still valid in a macro? And is the %{1} valid, as I've never seen an example -- and if not, how do I concatenate .new to %1?
If this is wrong, how do I do it?
tl;dr Yes, that looks basically correct to me. See http://www.rpm.org/wiki/PackagerDocs/Macros for some (somewhat outdated but still largely relevant) documentation.
Macros that are to be expanded in a shell context in a spec file just want to expand to the literal lines that you would write in the spec file section manually.
So assuming you want something to the effect of:
%install
....
sed -e 's:${LIBEXECDIR}:%{_libexecdir}:g' -e 's:${LOCALSTATEDIR}:%{_localstatedir}:g' -e 's:${SYSCONFIGDIR}:%{_sysconfdir}:g' 'some_file' > 'some_file.new' && mv 'some_file.new' 'some_file'
....
And you want to call your macro as %repl_vars some_file then you want a macro roughly like this:
%define repl_vars() sed -e 's:${LIBEXECDIR}:%{_libexecdir}:g' -e 's:${LOCALSTATEDIR}:%{_localstatedir}:g' -e 's:${SYSCONFIGDIR}:%{_sysconfdir}:g' '%{1}' > '%{1}.new' && mv '%{1}.new' '%{1}'
Notice I switched to single quotes instead of double quotes to avoid $ from being evaluated and needing to be escaped. I also dropped the wrapping () because this didn't seem to need the forced sub-shell.
Related
How to pass argument to sed without input files. The sed is in single quote and has pipe in it already.
git filter-branch -f --index-filter \
'git ls-files -s | sed -i "s-\t\"*-&dirname/-" |
GIT_INDEX_FILE=$GIT_INDEX_FILE.new \
git update-index --index-info &&
mv "$GIT_INDEX_FILE.new" "$GIT_INDEX_FILE"' HEAD
The above code works fine if dirname is hard-coded. But i need to pass the dirname from command line arguments to script. I am trying like below but no luck.
'set subdir=$folder;git ls-files -s | sed -i "s-\t\"*-&$subdir/-" |
The sed says input file is missing. I can not directly pass the input file to sed. I am seeing error like below.
Rewrite 9c86de42b7f3228e3d45a278c8caf7e24c8e55cf (1/2) (0 seconds passed, remaining 0 predicted)
sed: no input files
You have two choices here. You can either evaluate $subdir to build up a fixed sed command that you then set as your filter; or you can evaluate a variable in the shell fragment that git filter-branch will invoke.
To understand the latter, realize that your --index-filter string becomes an ordinary shell variable:
--index-filter)
filter_index="$OPTARG"
;;
which is then passed to eval:
eval "$filter_index" < /dev/null ||
die "index filter failed: $filter_index"
The eval means that the expression in $filter_index, set from your --index-filter argument, has access to all the shell variables and functions in the filter-branch script. Unfortunately, none of its private variables holds the expression you'd like—but you can access its environment variables, which means you can put the value into an environment variable. In other words, you could supply subdir=<whatever> as an environment to your original expression.
In any case, as bk2204 answered, you need to remove the -i option. Besides that, some versions of sed don't accept \t as a tab character (presumably yours does, just be aware of this).
To expand the variable earlier, just do that. For instance:
... --index-filter \
'git ls-files -s | sed "s-\t\"*-&'$folder'/-" | ...
(I've removed the -i here myself). Note how this exits single quotes, expands $folder, then re-enters single quotes. If $folder might contain whitespace, be sure to use double quotes while expanding it here:
... --index-filter \
'git ls-files -s | sed "s-\t\"*-&'"$folder"'/-" | ...
The nesting of quotes here is pretty tricky: the stuff inside the single quotes is all one big string, provided as the argument that sets the variable $filter_index inside the filter-branch script. The eval runs it through a second pass of evaluation, breaking up into the pipeline (git ls-files, piped to sed, piped to git update-index) and running the various multiple commands, all of which have their stdin redirected to /dev/null.
You're using sed -i, which edits its command-line arguments (which are names of files) in place. However, you're reading from standard input and haven't provided any command-line arguments. If you want to just filter the standard input like this, omit the -i from your sed command.
There's a local variable in netmap/LINUX/configure named BUILDDIR and its value is BUILDDIR=$PWD.It should have to be redirected to $(#D) which is netmap package build directory, /usr/local/buildroot/output/build/netmap-master in my case;otherwise, object files will be outputed to buildroot root directory.
I created a variable named NETMAP_CURRENT_BUILD and let it be /usr/local/buildroot/output/build/netmap-master,$(#D),
and then I wanna replace BUILDDIR=$PWD to
BUILDDIR=/usr/local/buildroot/output/build/netmap-master. By using sample code as following, it can't be done.
Sample Code :(sed part worked fine at terminal console)
define NETMAP_BUILD_CMDS
NETMAP_CURRENT_DIR = $(sed -e 's/\//\\\//g' <<< "$(#D)") -- empty
echo "$$(sed -e 's/\//\\\//g' <<< "$(#D)")" -- this line works fine
...
sed -e 's/BUILDDIR=$$PWD/BUILDDIR=$(NETMAP_CURRENT_DIR)/g' -i $(#D)/LINUX/configure
(double $$PWD, it has to be like this, which means string $PWD is needed rather than its value.)
...
endef
You don't actually need this, see below. However, if you do need the result of a shell command in a make variable, use $(shell ...)
Since this is a makefile, the $ are interpreted by make, not by the shell. Therefore, make will try to evaluate sed -e 's/\//\\\//g' <<< "$(#D)" as a variable name. There is of course no variable with that name, so you get an empty string.
To let make run a shell command and store the result in a make variable, use the $(shell ...) function. So
NETMAP_CURRENT_DIR = $(shell sed -e 's/\//\\\//g' <<< "$(#D)")
Note that that should be done outside of the NETMAP_BUILD_CMDS, because the contents of NETMAP_BUILD_CMDS is in fact a shell script: make first expands all variables in that script, then passes it to the shell line-by-line. The shell will actually error out on the above statement because you have spaces around the = so NETMAP_CURRENT_DIR is interpreted as a command name.
If you want to store the result in a shell variable rather than a make variable, then the easiest solution is to use backticks `...` to delimit the command instead of $(...):
define NETMAP_BUILD_CMDS
NETMAP_CURRENT_DIR=`sed -e 's/\//\\\//g' <<< "$(#D)"`; \
sed -e 's/BUILDDIR=$$PWD/BUILDDIR=$$NETMAP_CURRENT_DIR/g' -i $(#D)/LINUX/configure
endef
However, in your case you don't need this at all.
First of all, you can do simple substitutions directly in make.
NETMAP_CURRENT_DIR = $(subst /,\/,$(#D))
Even better, you can simply use a different delimiter than / in your sed expression, then there is no need to quote it:
sed -e 's#BUILDDIR=$$PWD#BUILDDIR=$(#D)#g' -i $(#D)/LINUX/configure
One final note: modifications to the code like this are better done in NETMAP_POST_PATCH_HOOKS than in NETMAP_BUILD_CMDS. So finally, the best solution is:
define NETMAP_FIX_BUILDDIR
sed -e 's#BUILDDIR=$$PWD#BUILDDIR=$(#D)#g' -i $(#D)/LINUX/configure
endef
NETMAP_POST_PATCH_HOOKS += NETMAP_FIX_BUILDDIR
I am looking to write a simple script to perform a SSH command on many hosts simultaneously, and which hosts exactly are generated from another script. The problem is that when I run the script using sometihng like sed it doesn't work properly.
It should run like sshall.sh {anything here} and it will run the {anything here} part on all the nodes in the list.
sshall.sh
#!/bin/bash
NODES=`listNodes | grep "node-[0-9*]" -o`
echo "Connecting to all nodes and running: ${#:1}"
for i in $NODES
do
:
echo "$i : Begin"
echo "----------------------------------------"
ssh -q -o "StrictHostKeyChecking no" $i "${#:1}"
echo "----------------------------------------"
echo "$i : Complete";
echo ""
done
When it is run with something like whoami it works but when I run:
[root#myhost bin]# sshall.sh sed -i '/^somebeginning/ s/$/,appendme/' /etc/myconfig.conf
Connecting to all nodes and running: sed -i /^somebeginning/ s/$/,appendme/ /etc/myconfig.conf
node-1 : Begin
----------------------------------------
sed: -e expression #1, char 18: missing command
----------------------------------------
node-1 : Complete
node-2 : Begin
----------------------------------------
sed: -e expression #1, char 18: missing command
----------------------------------------
node-2 : Complete
…
Notice that the quotes disappear on the sed command when sent to the remote client.
How do I go about fixing my bash command?
Is there a better way of achieving this?
Substitute an eval-safe quoted version of your command into a heredoc:
#!/bin/bash
# ^^^^- not /bin/sh; printf %q is an extension
# Put your command into a single string, with each argument quoted to be eval-safe
printf -v cmd_q '%q ' "$#"
while IFS= read -r hostname; do
# run bash -s remotely, with that string passed on stdin
ssh -q -o 'StrictHostKeyChecking no' "$hostname" "bash -s" <<EOF
$cmd_q
EOF
done < <(listNodes | grep -o -e "node-[0-9*]")
Why this works reliably (and other approaches don't):
printf %q knows how to quote contents to be eval'd by that same shell (so spaces, wildcards, various local quoting methods, etc. will always be supported).
Arguments given to ssh are not passed to the remote command individually!
Instead, they're concatenated into a string passed to sh -c.
However: The output of printf %q is not portable to all POSIX-derived shells! It's guaranteed to be compatible with the same shell locally in use -- ksh will always parse output from printf '%q' in ksh, bash will parse output from printf '%q' in bash, etc; thus, you can't safely pass this string on the remote argument vector, because it's /bin/sh -- not bash -- running there. (If you know your remote /bin/sh is provided by bash, then you can run ssh "$hostname" "$cmd_q" safely, but only under this condition).
bash -s reads the script to run from stdin, meaning that passing your command there -- not on the argument vector -- ensures that it'll be parsed into arguments by the same shell that escaped it to be shell-safe.
You want to pass the entire command -- with all of its arguments, spaces, and quotation marks -- to ssh so it can pass it unchanged to the remote shell for parsing.
One way to do that is to put it all inside single quotation marks. But then you'll also need to make sure the single quotation marks within your command are preserved in the arguments, so the remote shell builds the correct arguments for sed.
sshall.sh 'sed -i '"'"'/^somebeginning/ s/$/,appendme/'"'"' /etc/myconfig.conf'
It looks redundant, but '"'"' is a common Bourne trick to get a single quotation mark into a single-quoted string. The first quote ends single-quoting temporarily, the double-quote-single-quote-double-quote construct appends a single quotation mark, and then the single quotation mark resumes your single-quoted section. So to speak.
Another trick that can be helpful for troubleshooting is to add the -v flag do your ssh flags, which will spit out lots of text, but most importantly it will show you exactly what string it's passing to the remote shell for parsing and execution.
--
All of this is fairly fragile around spaces in your arguments, which you'll need to avoid, since you're relying on shell parsing on the opposite end.
Thinking outside the box: instead of dealing with all the quoting issues and the word-splitting in the wrong places, you could attempt to a) construct the script locally (maybe use a here-document?), b) scp the script to the remote end, then c) invoke it there. This easily allows more complex command sequences, with all the power of shell control constructs etc. Debugging (checking proper quoting) would be a breeze by simply looking at the generated script.
I recommend reading the command(s) from the standard input rather than from the command line arguments:
cmd.sh
#!/bin/bash -
# Load server_list with user#host "words" here.
cmd=$(</dev/stdin)
for h in ${server_list[*]}; do
ssh "$h" "$cmd"
done
Usage:
./cmd.sh <<'CMD'
sed -i '/^somebeginning/ s/$/,appendme/' /path/to/file1
# other commands
# here...
CMD
Alternatively, run ./cmd.sh, type the command(s), then press Ctrl-D.
I find the latter variant the most convenient, as you don't even need for here documents, no need for extra escaping. Just invoke your script, type the commands, and press the shortcut. What could be easier?
Explanations
The problem with your approach is that the quotes are stripped from the arguments by the shell. For example, the argument '/^somebeginning/ s/$/,appendme/' will be interpreted as /^somebeginning/ s/$/,appendme/ string (without the single quotes), which is an invalid argument for sed.
Of course, you can escape the command with the built-in printf as suggested in other answer here. But the command becomes not very readable after escaping. For example
printf %q 'sed -i /^somebeginning/ s/$/,appendme/ /home/ruslan/tmp/file1.txt'
produces
sed\ -i\ /\^somebeginning/\ s/\$/\,appendme/\ /home/ruslan/tmp/file1.txt
which is not very readable, and will look ugly, if you print it to the screen in order to show the progress.
That's why I prefer to read from the standard input and leave the command intact. My script prints the command strings to the screen, and I see them just in the form I have written them.
Note, the for .. in loop iterates $IFS-separated "words", and is generally not preferred way to traverse an array. It is generally better to invoke read -r in a while loop with adjusted $IFS. I have used the for loop for simplicity, as the question is really about invoking the ssh command.
Logging into multiple systems over SSH and using the same (or variations on the same) command is the basic use case behind ansible. The system is not without significant flaws, but for simple use cases is pretty great. If you want a more solid solution without too much faffing about with escaping and looping over hosts, take a look.
Ansible has a 'raw' module which doesn't even require any dependencies on the target hosts, and you might find that a very simple way to achieve this sort of functionality in a way that frees you from the considerations of looping over hosts, handling errors, marshalling the commands, etc and lets you focus on what you're actually trying to achieve.
I'm debugging an old shell script; I want to check the values of all the variables used, it's a huge ugly script with approx more than 140 variables used. Is there anyway I can extract the variable names from the script and put them in a convenient pattern like:
#!/bin/sh
if [ ${BLAH} ....
.....
rm -rf ${JUNK}.....
to
echo ${BLAH}
echo ${JUNK}
...
Try running your script as follows:
bash -x ./script.bash
Or enable the setting in the script:
set -x
You can dump all interested variables in one command using:
set | grep -w -e BLAH -e JUNK
To dump all the variables to stdout use:
set
or
env
from inside your script.
You can extract a (sub)list of the variables declared in your script using grep:
grep -Po "([a-z][a-zA-Z0-9_]+)(?==\")" ./script.bash | sort -u
Disclaimer: why "sublist"?
The expression given will match string followed by an egal sign (=) and a double quote ("). So if you don't use syntax such as myvar="my-value" it won't work.
But you got the idea.
grep Options
-P --perl-regexp: Interpret PATTERN as a Perl regular expression (PCRE, see below) (experimental) ;
-o --only-matching: Print only the matched (non-empty) parts of a matching line, with each such part on a separate output line.
Pattern
I'm using a positive lookahead: (?==\") to require an egal sign followed by a double quote.
In bash, but not sh, compgen -v will list the names of all variables assigned (compare this to set, which has a great deal of output other than variable names, and thus needs to be parsed).
Thus, if you change the top of the script to #!/bin/bash, you will be able to use compgen -v to generate that list.
That said, the person who advised you use set -x did well. Consider this extension on that:
PS4=':$BASH_SOURCE:$LINENO+'; set -x
This will print the source file and line number before every command (or variable assignment) which is executed, so you will have a log not only of which variables are set, but just where in the source each one was assigned. This makes tracking down where each variable is set far easier.
I'm trying to write a shell script that does a search and replace inside a configuration file upon start-up.
The string we're trying to replace is:
include /etc/nginx/https.include;
and we want to replace it with a commented version:
#include /etc/nginx/https.include;
The file that contains the string that we want to replace is:
/etc/nginx/app-servers.include
I'm not a Linux guru and can't seem to find the command to do this.
perl -p -i -e 's%^(include /etc/nginx/https.include;)$%#$1%' /etc/nginx/ap-servers.include
If the line might not end in the ;, use instead:
perl -p -i -e 's%^(include /etc/nginx/https.include;.*)$%#$1%' /etc/nginx/ap-servers.include
If you want to preserve the original file, add a backup extension after -i:
perl -p -i.bak -e 's%^(include /etc/nginx/https.include;)$%#$1%' /etc/nginx/ap-servers.include
Now, explaining. The -p flag means replace in-place. All lines of the file will be fed to the expression, and the result will be used as replacement. The -i flag indicates the extension of the backup file. By using it without anything, you prevent generation of backups. The -e tells Perl to get the following parameter as an expression to be executed.
Now, the expression is s%something%other%. I use % instead of the more traditional / to avoid having to escape the slashes of the path. I use parenthesis in the expression and $1 in the substituted expression for safety -- if you change one, the other will follow. Thus, %#$1% is actually the second % of s, followed by the desired #, $1 indicating the pattern inside parenthesis, and the last % of s.
HTH. HAND.
sed -i 's/foo/bar/g' config.txt
This replaces all instances of foo (case insensitive) with bar in the file config.txt
Check out sed:
sed -i -r 's|^(include /etc/nginx/https.include;)$|#\1|' /etc/nginx/app-servers.include
-i means do the substitution in-place and -r means to use extended regular expressions.
cd pathname
for y in `ls *`;
do sed "s/ABCD/DCBA/g" $y > temp; mv temp $y;
done
This script shold replace string ABCD to DCBA in all the files in pathname