I'm on a shared webhost where I don't have permission to edit the global bash configuration file at /ect/bashrc. Unfortunately there is one line in the global file, mesg y, which puts the terminal in tty mode and makes scp and similar commands unavailable. My local ~./bashrc includes the global file as a source, like so:
# Source global definitions
if [ -f /etc/bashrc ]; then
. /etc/bashrc
fi
My current workaround uses grep to output the global file, sans offending line, into a local file and use that as a source.
# Source global definitions
if [ -f /etc/bashrc ]; then
grep -v mesg /etc/bashrc > ~/.bash_global
. ~/.bash_global
fi
Is there a way to do include a grepped file like this without the intermediate step of creating an actual file? Something like this?
. grep -v mesg /etc/bashrc > ~/.bash_global
lose the cat, its useless
source <(grep -v "mesg" /etc/bashrc)
the <() syntax is called process substitution.
. <(grep -v mesg /etc/bashrc)
I suggest to call mesg n :)
From memory, but something like
grep -v mesg /etc/bashrc | eval
should do the trick
Since i'm not sure eval will read stdin, you may need to rephrase it into
eval `grep -v mesg /etc/bashrc`
Related
Let's say I have .env file contains lines like below:
USERNAME=ABC
PASSWORD=PASS
Unlike the normal ones have export prefix so I cannot source the file directly.
What's the easiest way to create a shell script that loads content from .env file and set them as environment variables?
If your lines are valid, trusted shell but for the export command
This requires appropriate shell quoting. It's thus appropriate if you would have a line like foo='bar baz', but not if that same line would be written foo=bar baz
set -a # automatically export all variables
source .env
set +a
If your lines are not valid shell
The below reads key/value pairs, and does not expect or honor shell quoting.
while IFS== read -r key value; do
printf -v "$key" %s "$value" && export "$key"
done <.env
This will export everything in .env:
export $(xargs <.env)
Edit: this requires the environment values to not have whitespace. If this does not match your use case you can use the solution provided by Charles
Edit2: I recommend adding a function to your profile for this in any case so that you don't have to remember the details of set -a or how xargs works.
This is what I use:
function load_dotenv(){
# https://stackoverflow.com/a/66118031/134904
source <(cat $1 | sed -e '/^#/d;/^\s*$/d' -e "s/'/'\\\''/g" -e "s/=\(.*\)/='\1'/g")
}
set -a
[ -f "test.env" ] && load_dotenv "test.env"
set +a
If you're using direnv, know that it already supports .env files out of the box :)
Add this to your .envrc:
[ -f "test.env" ] && dotenv "test.env"
Docs for direnv's stdlib: https://direnv.net/man/direnv-stdlib.1.html
Found this:
http://www.commandlinefu.com/commands/view/12020/export-key-value-pairs-list-as-environment-variables
while read line; do export $line; done < <(cat input)
UPDATE So I've got it working as below:
#!/bin/sh
while read line; do export $line; done < .env
use command below on ubuntu
$ export $(cat .env)
The script is located here: https://github.com/docker-library/ghost/blob/master/docker-entrypoint.sh
#!/bin/bash
set -e
if [[ "$*" == npm*start* ]]; then
baseDir="$GHOST_SOURCE/content"
for dir in "$baseDir"/*/ "$baseDir"/themes/*/; do
targetDir="$GHOST_CONTENT/${dir#$baseDir/}"
mkdir -p "$targetDir"
if [ -z "$(ls -A "$targetDir")" ]; then
tar -c --one-file-system -C "$dir" . | tar xC "$targetDir"
fi
done
if [ ! -e "$GHOST_CONTENT/config.js" ]; then
sed -r '
s/127\.0\.0\.1/0.0.0.0/g;
s!path.join\(__dirname, (.)/content!path.join(process.env.GHOST_CONTENT, \1!g;
' "$GHOST_SOURCE/config.example.js" > "$GHOST_CONTENT/config.js"
fi
ln -sf "$GHOST_CONTENT/config.js" "$GHOST_SOURCE/config.js"
chown -R user "$GHOST_CONTENT"
set -- gosu user "$#"
fi
exec "$#"
From what I know, it says that if you use some variation of npm start to move some files around from $GHOST_SOURCE to $GHOST_CONTENT, do something to the config.js file, link the config file, set ownership of the content files, and then execute npm start as the user user. Otherwise, it just runs your commands normally.
The specifics are what are hard for me to understand because there are a lot of things from bash that I've never seen before. So I have a lot of questions.
for dir in "$baseDir"/*/ "$baseDir"/themes/*/; do
In the above, why do they specify both /*/ and /themes/*/? Shouldn't /*/ contain themes? Is * not a wildcard for some reason?
targetDir="$GHOST_CONTENT/${dir#$baseDir/}"
In the above, what is the point of # in the variable expansion?
tar -c --one-file-system -C "$dir" . | tar xC "$targetDir"
In the above, does this somehow save time? Why not use something like rsync? I understand the point of -C, but why -c and --one-file-system?
sed -r '
s/127\.0\.0\.1/0.0.0.0/g;
s!path.join\(__dirname, (.)/content!path.join(process.env.GHOST_CONTENT, \1!g;
' "$GHOST_SOURCE/config.example.js" > "$GHOST_CONTENT/config.js"
What does this sed command do? I know it's a replacement, but why the "$GHOST_SOURCE/config.example.js" > "$GHOST_CONTENT/config.js" as the end?
ln -sf "$GHOST_CONTENT/config.js" "$GHOST_SOURCE/config.js"
In the above, what is the point of this symlink? Why try to link them to each other if both files already exist?
set -- gosu user "$#"
In the above what does calling set with no args do?
I hope that's not too much. I felt making a separate question for each of these would be too much especially since it's all related to each other.
for dir in "$baseDir"/*/ "$baseDir"/themes/*/; do
In the above, why do they specify both /*/ and /themes/*/? Shouldn't
/*/ contain themes? Is * not a wildcard for some reason?
themes/ is in the first match, but themes/*/ is not, so you need the second entry to include the contents of themes.
targetDir="$GHOST_CONTENT/${dir#$baseDir/}"
In the above, what is the point of # in the variable expansion?
It removes the $baseDir prefix from $dir. So for example:
bash$ dir=/home/bmitch/data/docker
bash$ echo $dir
/home/bmitch/data/docker
bash$ echo ${dir#/home/bmitch}
/data/docker
tar -c --one-file-system -C "$dir" . | tar xC "$targetDir"
In the above, does this somehow save time? Why not use something like
rsync? I understand the point of -C, but why -c and --one-file-system?
rsync may not be installed on every machine by default, tar is fairly universal. The -c is to create, vs extract, and --one-file-system avoids tar continuing to an outside mount point (nfs, symlink to root, etc).
sed -r '
s/127\.0\.0\.1/0.0.0.0/g;
s!path.join\(__dirname, (.)/content!path.join(process.env.GHOST_CONTENT, \1!g;
' "$GHOST_SOURCE/config.example.js" > "$GHOST_CONTENT/config.js"
What does this sed command do? I know it's a replacement, but why the
"$GHOST_SOURCE/config.example.js" > "$GHOST_CONTENT/config.js" as the
end?
config.example.js is the input (last arg to the sed), config.js is the output (after the >). So it takes the config.example.js, change the ip address from 127.0.0.1 to 0.0.0.0, effectively listening on all interfaces/ip's instead of just internally on the loopback. The second half of the sed is changing the path.join arguments from __dirname to process.env.GHOST_CONTENT.
ln -sf "$GHOST_CONTENT/config.js" "$GHOST_SOURCE/config.js"
In the above, what is the point of this symlink? Why try to link them
to each other if both files already exist?
The $GHOST_SOURCE/config.js is replaced (-f) with a link to $GHOST_CONTENT/config.js. Symbolic links give a file name reference to another actual file, so there will be two names, but one copy of the data, which means you will only have a single configuration in this situation.
set -- gosu user "$#"
In the above what does calling set with no args do?
This changes the values of $1, $2, ... $n to be $1=gosu, $2=user, $3=the old $1, $4=the old $2..., essentially adding the gosu and user to the beginning of the passed parameters to the script. The -- makes sure that set doesn't interpret any values from $# as a flag for itself.
The following is iptable save file, which I modified by setting some variables like you see below.
-A OUTPUT -o $EXTIF -s $UNIVERSE -d $INTNET -j REJECT
I also have a bash script which is defining this variables and should call iptables-restore with the save file above.
#!/bin/sh
EXTIF="eth0"
INTIF="eth1"
INTIP="192.168.0.1/32"
EXTIP=$(/sbin/ip addr show dev "$EXTIF" | perl -lne 'if(/inet (\S+)/){print$1;last}');
UNIVERSE="0.0.0.0/0"
INTNET="192.168.0.1/24"
Now I need to use
/sbin/iptables-restore <the content of iptables save file>
in bash script and somehow insert the text file on top to this script, so the variables will be initialized. Is there any way to do that?
UPDATE: even tried this
/sbin/iptables-restore -v <<-EOF;
$(</etc/test.txt)
EOF
Something like this:
while read line; do eval "echo ${line}"; done < iptables.save.file | /sbin/iptables-restore -v
or more nicely formatted:
while read line
do eval "echo ${line}"
done < iptables.save.file | /sbin/iptables-restore -v
The eval of a string forces the variable expansion stuff.
Use . (dot) char to include one shell script to another:
#!/bin/sh
. /path/to/another/script
In your shell script:
. /path/to/variable-definitions
/sbin/iptables-restore < $(eval echo "$(</path/to/template-file)")
or possibly
/sbin/iptables-restore < <(eval echo "$(</path/to/template-file)")
How can I find out where an alias is defined on my system? I am referring to the kind of alias that is used within a Terminal session launched from Mac OS X (10.6.3).
For example, if I enter the alias command with no parameters at a Terminal command prompt, I get a list of aliases that I have set, for example:
alias mysql='/usr/local/mysql/bin/mysql'
However, I have searched all over my system using Spotlight and mdfind in various startup files and so far can not find where this alias has been defined. ( I did it a long time ago and didn't write down where I assigned the alias).
For OSX, this 2-step sequence worked well for me, in locating an alias I'd created long ago and couldn't locate in expected place (~/.zshrc).
cweekly:~ $ which la
la: aliased to ls -lAh
cweekly:~$ grep -r ' ls -lAh' ~
/Users/cweekly//.oh-my-zsh/lib/aliases.zsh:alias la='ls -lAh'
Aha! "Hiding" in ~/.oh-my-zsh/lib/aliases.zsh. I had poked around a bit in .oh-my-zsh but had overlooked lib/aliases.zsh.
you can just simply type in alias on the command prompt to see what aliases you have. Otherwise, you can do a find on the most common places where aliases are defined, eg
grep -RHi "alias" /etc /root
First use the following commands
List all functions
functions
List all aliases
alias
If you aren't finding the alias or function consider a more aggressive searching method
Bash version
bash -ixlc : 2>&1 | grep thingToSearchHere
Zsh version
zsh -ixc : 2>&1 | grep thingToSearchHere
Brief Explanation of Options
-i Force shell to be interactive.
-c Take the first argument as a command to execute
-x -- equivalent to --xtrace
-l Make bash act as if invoked as a login shell
Also in future these are the standard bash config files
/etc/profile
~/.bash_profile or ~/.bash_login or ~/.profile
~/.bash_logout
~/.bashrc
More info: http://www.heimhardt.com/htdocs/bashrcs.html
A bit late to the party, but I was having the same problem (trying to find where the "l." command was aliased in RHEL6), and ended up in a place not mentioned in the previous answers. It may not be found in all bash implementations, but if the /etc/profile.d/ directory exists, try grepping there for unexplained aliases. That's where I found:
[user#server ~]$ grep l\\. /etc/profile.d/*
/etc/profile.d/colorls.csh:alias l. 'ls -d .*'
/etc/profile.d/colorls.csh:alias l. 'ls -d .* --color=auto'
/etc/profile.d/colorls.sh: alias l.='ls -d .*' 2>/dev/null
/etc/profile.d/colorls.sh:alias l.='ls -d .* --color=auto' 2>/dev/null
The directory isn't mentioned in the bash manpage, and isn't properly part of where bash searches for profile/startup info, but in the case of RHEL you can see the calling code within /etc/profile:
for i in /etc/profile.d/*.sh ; do
if [ -r "$i" ]; then
if [ "${-#*i}" != "$-" ]; then
. "$i"
else
. "$i" >/dev/null 2>&1
fi
fi
done
Please do check custom installations/addons/plugins you have added, in addition to the .zshrc/.bashrc/.profile etc files
So for me: it was git aliased to 'g'.
$ which g
g: aliased to git
Then I ran the following command to list all aliases
$ alias
I found a whole lot of git related aliases that I knew I had not manually added.
This got me thinking about packages or configurations I had installed. And so went to the
.oh-my-zsh
directory. Here I ran the following command:
$ grep -r 'git' . |grep -i alias
And lo and behold, I found my alias in :
./plugins/git/git.plugin.zsh
I found the answer ( I had been staring at the correct file but missed the obvious ).
The aliases in my case are defined in the file ~/.bash_profile
Somehow this eluded me.
For more complex setups (e.g. when you're using a shell script framework like bash-it, oh-my-zsh or the likes) it's often useful to add 'alias mysql' at key positions in your scripts. This will help you figure out exactly when the alias is added.
e.g.:
echo "before sourcing .bash-it:"
alias mysql
. $HOME/.bash-it/bash-it.sh
echo "after sourcing bash:"
alias mysql
I think that maybe this is similar to what ghostdog74 meant however their command didn't work for me.
I would try something like this:
for i in `find . -type f`; do # find all files in/under current dir
echo "========"
echo $i # print file name
cat $i | grep "alias" # find if it has alias and if it does print the line containing it
done
If you wanted to be really fancy you could even add an if [[ grep -c "alias" ]] then <print file name>
The only reliable way of finding where the alias could have been defined is by analyzing the list of files opened by bash using dtruss.
If
$ csrutil status
System Integrity Protection status: enabled.
you won't be able to open bash and you may need a copy.
$ cp /bin/bash mybash
$ $ codesign --remove-signature mybash
and then use
sudo dtruss -t open ./mybash -ic exit 2>&1 | awk -F'"' '/^open/ {print substr($2, 0, length($2)-2)}'
to list all the files where the alias could have been defined, like
/dev/dtracehelper
/dev/tty
/usr/share/locale/en_CA.UTF-8/LC_MESSAGES/BASH.mo
/usr/share/locale/en_CA.utf8/LC_MESSAGES/BASH.mo
/usr/share/locale/en_CA/LC_MESSAGES/BASH.mo
/usr/share/locale/en.UTF-8/LC_MESSAGES/BASH.mo
/usr/share/locale/en.utf8/LC_MESSAGES/BASH.mo
/usr/share/locale/en/LC_MESSAGES/BASH.mo
/Users/user/.bashrc
/Users/user/.bash_aliases
/Users/user/.bash_history
...
Try: alias | grep name_of_alias
Ex.: alias | grep mysql
or, as already mentioned above
which name_of_alias
In my case, I use Oh My Zsh, so I put aliases definition in ~/.zshrc file.
I have a bash script that creates a Subversion patch file for the current directory. I want to modify it to zip the produced file, if -z is given as an argument to the script.
Here's the relevant part:
zipped=''
zipcommand='>'
if [ "$1" = "-z" ]
then
zipped='zipped '
filename="${filename}.zip"
zipcommand='| zip >'
fi
echo "Creating ${zipped}patch file $filename..."
svn diff $zipcommand $filename
This doesn't work because it passes the | or > contained in $zipcommand as an argument to svn.
I can easily work around this, but the question is whether it's ever possible to use these kinds of operators when they're contained in variables.
Thanks!
I would do something like this (use bash -c or eval):
zipped=''
zipcommand='>'
if [ "$1" = "-z" ]
then
zipped='zipped '
filename="${filename}.zip"
zipcommand='| zip -#'
fi
echo "Creating ${zipped}patch file $filename..."
eval "svn diff $zipcommand $filename"
# this also works:
# bash -c "svn diff $zipcommand $filename"
This appears to work, but my version of zip (Mac OS X) required that i change the line:
zipcommand='| zip -#'
to
zipcommand='| zip - - >'
Edit: incorporated #DanielBungert's suggestion to use eval
eval is what you are looking for.
# eval 'printf "foo\nbar" | grep bar'
bar
Be careful with quote characters on that.
Or you should try zsh shell whic allows to define global aliases, e.g.:
alias -g L='| less'
alias -g S='| sort'
alias -g U='| uniq -c'
Then use this command (which is somewhat cryptic for the ones who took a look from behind ;-) )
./somecommand.sh S U L
HTH
Open a new file handle on either a process substitution to handle the compression or on the named file. Then redirect the output of svn diff to that file handle.
if [ "$1" = "-z" ]; then
zipped='zipped '
filename=$filename.zip
exec 3> >(zip > "$filename")
else
exec 3> "$filename"
fi
echo "Creating ${zipped}patch file $filename"
svn diff >&3