how do I find where a executable is present in macosx? - macos

I have a command called youtube-dl .. but dont know where it is installed.. i can run it from shell.. how do i find where it is installed ? which youtube-dl doesnt say anything..

Bash has a command that will show whether a command is an alias, a function or an executable in your path (and, if so, where):
type -a youtube-dl
It's much better than which which doesn't include aliases or functions.

If you can't find it with which (or whereis) then it could be:
a function defined in .bashrc or .profile (or some other file the shell loads on startup or login)
an alias defined in one of the above files.
You can search your environment for youtube-dl:
$ set | grep youtube-dl
or save it to some file and load it into a texteditor:
$ set >myenv
$ open -a textedit myenv
and for the aliases:
$ alias >myalias
or
$ alias | grep youtube-dl

Have you tried
whereis youtube-dl
?
Otherwise you could just search for it:
find / -name youtube-dl

Related

How to get readlink -e on M1 Macs which also works when used in bash scripts?

I am using several bash scripts for build and deployment processes which use readlink with the -e option. Since this option is not available I followed this suggest to install coreutils and create a symbolink between greadlink and readlink.
This worked perfectly on my Intel mac but when I recently switch to M1 mac I realized that the path to greadlink and readlink are changed so I tried this:
ln -s /opt/homebrew/bin/greadlink /usr/bin/readlink
Which gave me an error: Operation not permitted
I realised that this is because of the System Integrity Protection
How can I still use readlink -e in my bash scripts without deactivate the System Integrity Protection?
One approach is to create a script named readlink somewhere in your PATH with the following content.
#!/bin/sh
exec greadlink "$#"
Just make sure that the relative path of script named readlink comes before /usr/bin/ since the system readlink is in /usr/bin when you run:
declare -p PATH
or
echo "$PATH"
An example how to do it:
Create a directory in ~/, name it scripts since it will have script as contents.
mkdir -p ~/scripts
Edit ~/.bashrc to include the created directory in the PATH env variable.
if [[ :$PATH: != *:$HOME/scripts:* ]]; then
PATH=$HOME/scripts:$PATH
fi
Source ~/.bashrc
source ~/.bashrc
Create a script name readlink inside the ~/scripts directory with the following contents:
#!/bin/sh
exec /opt/homebrew/bin/greadlink "$#"
Make it executable
chmod +x ~/scripts/readlink
Check which readlink is the first in PATH
type -a readlink
Output should be something like.
readlink is /home/zlZimon/scripts/readlink
readlink is /usr/bin/readlink
Note that the current work around is for a single user, or rather the user that has scripts directory in PATH, for a system wide approach one can use the path from homebrew or /usr/local/ or whichever default is available for all users.

bash, how to dot source a downloaded file (using curl) into bash

I have .sh file that I would like to dotsource into my running environment. This does not work:
curl -s https://raw.githubusercontent.com/bla/bla/master/stuff.sh | bash
The above does not work, i.e. The script runs, but the environment variables and things inside stuff.sh are not dotsourced into the running environment. I also tried:
. curl -s https://raw.githubusercontent.com/bla/bla/master/stuff.sh | bash
curl -s https://raw.githubusercontent.com/bla/bla/master/stuff.sh | bash source
curl -s https://raw.githubusercontent.com/bla/bla/master/stuff.sh | source bash
All fail. Would appreciate knowing how this can be done?
I am not a bash expert, but if you are willing to accept some drawbacks, the easiest method to do that is without pipes. I believe that it should be possible when you separate download and sourcing:
prompt># curl -s https://raw.githubusercontent.com/bla/bla/master/stuff.sh > ./stuff.sh
prompt># . ./stuff.sh
From the bash manual (man bash), in the chapter about the builtin source command:
Read and execute commands from filename [...]
There is no mentioning about standard input as a possible source for the commands which should be sourced.
However, as hanshenrik stated in his answer, you always can use process substitution to create a temporary (and invisible on the file system) file which you can feed to source. The syntax is <(list), where <(list) is expanded to a unique file name chosen by bash, and list is a sequence of commands whose output is put into that file (the file does not appear on the file system, though).
Process substitution is documented in the bash manual (man bash) in a paragraph under that exact caption.
try
source <(curl -s https://raw.githubusercontent.com/bla/bla/master/stuff.sh)
i tried doing
curl -s https://raw.githubusercontent.com/bla/bla/master/stuff.sh | source /dev/stdin
but that didn't work for some reason, no idea why (anyone knows?)

How to execute HandbrakeCLI from script?

I'm trying to execute a script that runs a Handbrake video conversion.
If I run the following command from the terminal, it works fine:
HandbrakeCLI -i inputtestfile.mp4 -o outputtestfile.mp4 -z "Preset"
If I put this into a .sh script (and give the script execution rights using chmod a+x), I get the following error:
HandbrakeCLI: Command not found
If I then put the full path to HandbrakeCLI, it then works, for example:
/usr/local/Cellar/handbrake/1.2.0/bin/HandBrakeCLI -i inputtestfile.mp4 -o outputtestfile.mp4 -z "Preset"
However, the above method is inconvenient because every time I update Handbrake to a new version, I'll have to update the script.
How can I add Path (I think this is right), to the script, so I can just use:
HandbrakeCLI -i inputtestfile.mp4 -o outputtestfile.mp4 -z "Preset"
Thanks
You can begin the .sh script with:
PATH=$PATH:/usr/local/Cellar/handbrake/1.2.0/bin
path is an environment variable that affects where sh would look unqualified files names (commands) from.
And for the changing version you can parse HandBrake --version output and use it as a variable instead of 1.2.0 string in PATH.

How to check for path expansion for executables

Like most makefiles, I have some bash scripts that use variables for executables. For example, $mysql_exec for /usr/bin/mysql. I would like to be able to say something like:
mysql_exec=mysql
to use $PATH or
mysql_exec=/usr/bin/mysql
to get an absolute location without $PATH. I also want to check to see if the executable is valid using something like this:
if [ ! -x $mysql_exec ] ...
However, this command:
if [ ! -x "mysql" ]; then print "oh oh"; fi
Actually prints "oh oh", even though mysql is in my $PATH. From the command-line, typing mysql has the same effect as typing /usr/bin/mysql. So, how do I get bash really check to see if $mysql_exec is an executable ($PATH and all)?
In Bash, you can use the built-in type -P to force a resolution against the PATH or type -p to show the path only if there's no alias or function by that name. Using type avoids calling an external such as which.
Something like this may do what you're looking for:
[ -x "$(type -p "$mysql_exec")" ]
whether you use
mysql_exec=mysql
or
mysql_exec=/usr/bin/mysql
which is a small program that checks $PATH for a program specified as an argument:
$ which mysql
/usr/bin/mysql
Another useful utility (that isn't installed on all systems but is included in GNU CoreUtils) is readlink. readlink can give you back a full and absolute path, without symlinks. For example:
$ cd ~me/bin
$ ln -s `which mysql` mysupersql
$ readlink -f mysupersql
/usr/bin/mysql
I often use a combination of both so I know that the path is both absolute and not a symlink:
mysql_exec=$(readlink -f `which mysql`)
if [ ! -x "$mysql_exec" ] ; then
...
To add to Kaleb's answer, you an also check if the file is a symlink using if [-L $file] and follow that symlink if you can't install readlink. The rest of the check though remains as the way Kaleb mentioned.

How to find out where alias (in the bash sense) is defined when running Terminal in Mac OS X

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.

Resources