At first I had
touch $NAME_OF_FILE$DATE.$FILE_EXT
then I changed it to
PATH="Logs/"
touch $PATH$NAME_OF_FILE$DATE.$FILE_EXT
The file is created correctly in the folder, however only echos are being printed in there because says commands are not found like grep, awk, and others.
EDIT: The folder is already created on my desktop
Thanks
Alan
PATH is an environment variable that specifies where executables are located and is used by your shell to look for commands executables (grep, awk, ...). You should not override it in your script.
Try:
MYPATH="Logs/"
touch $MYPATH$NAME_OF_FILE$DATE.$FILE_EXT
To understand what PATH is open a shell and type echo $PATH. You will see it contains the directories where your commands executables are.
Related
I am building a source file with some alias to executable files (these are working just fine) and assigning directories to variables in order to get to the directory quicker, with less typing. For example, if I source example.source:
#!/usr/bin/bash
mydir="/path/to/some/dir"
I can get to /path/to/some/dir with
cd $mydir
However, I am not being able to use tab complete to navigate through other sub-directories like I would do by typing the complete path. I mean, if I use the tab key to complete the variable I get cd $mydir but not cd $mydir/ (I have to delete the last space character and manually type the slash / to see the next sub-directories). Hope this is an understandable question. Is there any workaround for this?
EDIT: the linux distribution I'm using is Slackware Linux 3.2.31.c x86_64 GenuineIntel GNU/Linux
EDIT2: GNU bash, version 4.2.37(2)-release
Apparently this feature is starting to be implemented in bash 4.3, release 26-Feb-2014 09:25.
Reading the NEWS file in bash 4.3 I found this:
i. The word completion code checks whether or not a filename
containing a
shell variable expands to a directory name and appends `/' to the word
as appropriate. The same code expands shell variables in command names
when performing command completion.
Unfortunately I cannot do a de novo installation of bash (because I'm working on a server) but I hope this can help others.
If I understand your question, then I believe it can be solved by putting this at the top of your example.source. This will list your contents every-time that you cd.
#!/usr/bin/bash
# Make cd change directories and then list the contents
function cd() {
builtin cd $*;
ls;
}
mydir="/path/to/some/dir"
cd $mydir
My other suggestion is to try to put cd within your alias. Something like this:
mydir="cd /path/to/some/dir"
$mydir
I want to add a small script to the linux PATH so I don't have to actually run it where it's physically placed on disk.
The script is quite simple is about giving apt-get access through a proxy I made it like this:
#!/bin/bash
array=( $# )
len=${#array[#]}
_args=${array[#]:1:$len}
sudo http_proxy="http://user:password#server:port" apt-get $_args
Then I saved this as apt-proxy.sh, set it to +x (chmod) and everything is working fine when I am in the directory where this file is placed.
My question is : how to add this apt-proxy to PATH so I can actually call it as if it where the real apt-get ? [from anywhere]
Looking for command line only solutions, if you know how to do by GUI its nice, but not what I am looking for.
Try this:
Save the script as apt-proxy (without the .sh extension) in some directory, like ~/bin.
Add ~/bin to your PATH, typing export PATH=$PATH:~/bin
If you need it permanently, add that last line in your ~/.bashrc. If you're using zsh, then add it to ~/.zshrc instead.
Then you can just run apt-proxy with your arguments and it will run anywhere.
Note that if you export the PATH variable in a specific window it won't update in other bash instances.
You want to define that directory to the path variable, not the actual binary e.g.
PATH=$MYDIR:$PATH
where MYDIR is defined as the directory containing your binary e.g.
PATH=/Users/username/bin:$PATH
You should put this in your startup script e.g. .bashrc such that it runs each time a shell process is invoked.
Note that order is important, and the PATH is evaluated such that if a script matching your name is found in an earlier entry in the path variable, then that's the one you'll execute. So you could name your script as apt-get and put it earlier in the path. I wouldn't do that since it's confusing. You may want to investigate shell aliases instead.
I note also that you say it works fine from your current directory. If by that you mean you have the current directory in your path (.) then that's a potential security risk. Someone could put some trojan variant of a common utility (e.g. ls) in a directory, then get you to cd to that directory and run it inadvertently.
As a final step, after following the solution form proposed by #jlhonora (https://stackoverflow.com/a/20054809/6311511), change the permissions of the files in the folder "~/bin". You can use this:
chmod -R 755 ~/bin
make an alias to the executable into the ~/.bash_profile file and then use it from anywhere or you can source the directory containing the executables you need run from anywhere and that will do the trick for you.
adding to #jlhonora
your changes in ~./bashrc or ~./zshrc won't reflect until you do
source ~./zshrc or source ./bashrc , or restart your pc
I am trying to install some scripts into linux and follwoing line is given as instruction.
Install the xyz script into some convenient directory in $PATH.
but I'm unable to understand what exactly does it mean.How do I install given script in $PATH directory.Script is placed under /users/username/ Dir.
In a terminal type echo $PATH. You will see a list of directories. Put your script, or a link to your script in one of those directories, typically in /usr/local/bin.
its a bad description of the script-author :) usually, in your $PATH are multiple directories mentioned, separated by colon.
you can echo them:
echo $PATH
What the Author means: just copy the script in a directory which is in your $PATH, e.g. /usr/local/bin
$PATH is a list of directories where bash looks for executables.
The given instruction suggests that yours scripts should be put in one of these directories.
An alternative is to put your scripts in any directory and add that directory to $PATH. In your case, add the following line in your $HOME/.bash_profile configuration file:
export PATH=$PATH:/users/username
I have a program written in C, which is named computeWeight.c and to compile it i use the following code
chaitu#ubuntu:~$ gcc -Wall -o computeWeight computeWeight.c
//to execute it:
chaitu#ubuntu:~$ ./computeWeight
Do i have any mechansim where i can directly use as mentioned below,
chaitu#ubuntu:~$ computeWeight
Should i be changing any permissions on the executable to get this?
You need to add "." to your path. Some people regard this as dangerous, though. See for instance http://www.arsc.edu/support/policy/dotinpath.html .
The $PATH variable define the places where linux would look for executables (try typing echo $PATH in a terminal). You need to put that file in one of those places. One way is to add a bin folder in your home directory, put the executable file there, and add this line (which adds the bin directory in your home folder to the search path) to your .cshrc file so that it'd be executed for every shell:
set PATH = ($PATH $HOME/bin)
With that said I don't think typing ./ is that bad.
export PATH=$PATH:.
I'm pretty new to programming for Linux environments, so I don't exactly know what to search for in order to answer this question for myself. I need to understand how applications set the shell to accept a certain command to start them. For example, you can start Firefox from the command line by executing the command: firefox.
I don't know where this is defined. Makefile? Configure script? In the source code itself?
Any resources / reading on Linux programming tidbits like these would be greatly appreciated!
Thank you.
Firefox is launched by the command "firefox" because there is an executable file in one of the folders in the $PATH environment variable called "firefox".
Are you talking about the PATH variable? It seems like you are.
In linux, you should be able to type: "echo $PATH" (without quotes) and get a ":"-separated list of locations where programs are located (like firefox).
If you need to add something to your path, you should be able to do:
export PATH=$PATH:/another/directory
In your shell (which is most likely bash)
You can also type:
which firefox
To display the location of the firefox executable.
Typically the shell is going to have an environment variable called $PATH set. This is just an ordered list of all the directories to look when somebody types in a command. As soon as it finds an executable file (by which I mean a file for which you have execute permissions, not a file ending in .exe) with the same name as whatever was typed, it will run that file. Common directories in $PATH might be /bin, /usr/local/bin, ~/bin, etc.
So, when you type 'firefox', the shell looks through all the directories in $PATH until it finds /usr/local/bin/firefox, which it then runs. To make your own programs run the same way, you'll either need to put them (or a symbolic link to them) in a directory that is likely to be in every user's path (/usr/local/bin/ is a good choice), or you'll need to get your users to add your program's directory to their $PATH.
For a more complete description, see the Wikipedia article about the $PATH variable.
As an alternative to the modification of $PATH mentioned earlier, you could also copy or link your executable in one of the directories already in your $PATH. more specifically, /usr/local/bin/ is available on most UNIX system for pretty much this purpose (installing software outside the default package management of the operating system).
It has to be in the path as everyone else mentioned, but you might also need to make it executable with something like this:
chmod +x /path/to/file
And if it's a script there's usually a shebang at the top that tells the os what to use to execute it:
#! /usr/bin/python
Often, large packages are installed in /opt with a wrapper script or link somewhere in the PATH. For example, on my system, Google Picasa is installed in /opt/google/picasa and there is a symlink at /usr/bin/picasa to /opt/google/picasa/3.0/picasa
Firefox is at /usr/bin/firefox on my system and that's a symlink to /usr/bin/firefox-3.0 which is itself a symlink to /usr/lib/firefox-3.0.11/firefox.sh - That shell file fumbles around until it finally runs /usr/lib/firefox-3.0.11/firefox (unless it finds a reason to do something else). That, finally, is a binary executable. So /usr/lib is where firefox is installed, for me.
You can use this command to find out where a program is:
type -a firefox
Then, you can find out what kind of file it is using this:
file /usr/bin/firefox
Also see the Filesystem Heirarchy Standard for more information about recommended locations for files and programs.