I have an annoying problem when using Screen on my SLED10 machine. When changing directory (cd, chdir, pushd/popd) the resulting path is echoed in the terminal.
user#/home/user> cd ..
Directory: /home
user#/home>
This problem only seem to exist in Screen. I have checked my prompt and it does not contain anything related to this behavior. I am using tcsh/xterm.
How do I get rid of the echo of the directory?!
Best Regards,
Stefan
Maybe cd has been overridden with an alias or a function.
Once in screen, use:
alias cd to see if there is an alias and declare -f to check your functions.
Related
So,
cd .. moves back into the parent directory.
I'd like to add functionality so that I could type...
cd ...
... and move into the parent directory's parent directory.
and consequently move up an additional tier for each extra .
The idea came from an SO answer about a script called 'up' which should do essentially the same thing. But I'm curious if it'd be possible to just add to the cd command.
After a quick search I've noticed that cd is a bash builtin so I don't think it'll be possible to edit any original code. Would it be possible to create a new cd(.sh) script that executes in place of the builtin cd command when valid arguments are provided? What other ways might this be accomplished by?
Note: this is more for learning than practical application, I just think it'd be a cool thing to do.
Thanks!
You can define an alias in your .bashrc file:
alias ...='cd ../..'
and after that you can issue ... to go up two directories. If you only want that alias for cd it will work.
You can add the following lines to the file ~/.bashrc
alias cd..='cd ..'
alias cd...='cd ../..'
and so on.
After adding this lines close the terminal and open an new one. There you can us cd.. to go one directory up, cd... to go two directories up ...
I am on a RedHat csh.
I just modified ~/.cshrc with a wrong path and resulting in an syntax-error.
my shell just not recognize ls or gedit. So, when I again try to modify, it is not again opening with gedit ~/.cshrc.
When I boot the system it is not starting the profile.
I Have the root access and root profile is fine. Can I edit it from root.
Please help me to remove last two lines i have added to /.cshrc, using root-profile so that it works normal as previous.
thanks.
I'm guessing your PATH isn't getting set properly due to the syntax-error in your .cshrc (assumption since you mention ls isn't working). Try the following from your shell:
echo $PATH
echo is a built-in and should always work. If it returns nothing, is empty, or doesn't include a list of paths similar to /bin, /usr/bin, etc ... then your path is indeed incorrect. Use the full path to gedit on the command line like:
/usr/bin/gedit ~/.cshrc
I tried running a script file using bash but it showed an error
bash-3.2$ example.sh : command not found
I also tried
ls -l example.sh
I found that it was not executable, so I used
sudo chmod 777 example.sh
I again tried running it but same error was coming. I double checked that I am in the same folder as the file using ls. But still I am not able to execute the script file.
I finally tried making a dummy script file and running it , and found the same error
I think there is some problem with BASH. Can some one help me with what is the problem?
I am working on redhat, bash was already installed in my system
Since I am newbie on linux any help would be appreciated
bash search for commands in your $PATH. Apparently the current directory, ., is not in your $PATH. (This is a good thing; having . in your $PATH is insecure.)
You'll need to specify a directory name. Just type:
./example.sh
Incidentally, doing:
sudo chmod 777 example.sh
is two kinds of overkill. First, you don't need to use sudo; use sudo only when you actually need to. Presumably your personal account owns the file, so you can just use chmod directly.
Second, 777 is way too permissive. It allows anyone on the system to read, execute, or modify example.sh. (If you're the only person on the system it may not matter much, but it's still a bad habit.) Typically you should use 755 for directories and for files that need to be executable, and 644 for files that don't need to be executable.
Or just use
chmod +x example.sh
to set execute permission (your umask will prevent that from setting the permissions too loosely).
. (the current directory) is probably not on your path. Try ./example.sh or bash example.sh. You could also add . to your PATH environment variable, but that's generally frowned upon.
Your bash PATH probably doesn't include ., try running it by typing:
./example.sh
When you type a command, your shell searches your path to try to find the command, if the current directory (e.g. .) isn't part of the path, the script that you are trying to run won't be found. You'd have to explicitly give it the path to where this command is. And since it's in your current directory, you can just add ./ in front of the command.
first confirm the bash path
to check the path of bash use:
which bash
if you get "/bin/bash"
then add
#!/bin/bash
...
...
or whatever is the path on first line of your bash script
I'm using a command which I don't know where the information is stored.
alias nup='ps ax | grep "nginx"'
Where is this alias saved?
It depends upon your environment and configurations.
For bash, I would generally put it in a .bashrc file that in a home directory.
In ubuntu alias get stored in the .bashrc file.
If you are typing alias update_linux='sudo apt-get update' in the terminal, then it will create an alias temporarily. It works until you close your terminal.
To add an alias permanently you can edit ~/.bashrc and add the alias to it:
gedit ~/.bashrc
and add alias at the end
alias update_linux='sudo apt-get update'
Don't forget to refresh the .bashrc configuration, by running:
source ~/.bashrc
for more details on creating alias you can read following blog: Codebucket.
Try
grep alias ~/.*
grep alias /etc/*
to find most aliases. In /etc/default, /etc/environment, depending on your distribution (I read: ubuntu)/version there might be more in other /etc/ -subdirs.
I am using Ubuntu 14.04, and you may put your aliases directly in .bashrc, but you may also create a file in ~/.bash_aliases, which will hold your aliases separately and load them automatically.
By default, the .bash_aliases file is not there. You will need to create it, but first make sure you create it in the same directory as your .bashrc file
To find your .bashrc, you may use this:
sudo find / -name .bashrc -print
My output was:
/root/.bashrc
/home/ddropik/.bashrc
/etc/skel/.bashrc
As mentioned by OddityOverseer and ranendra, I am probably interested in the one in my home directory, that is /home/ddropik/.bashrc. So I navigate to my home directory, cd ~/
Now create the .bash_aliases file with touch .bash_aliases and then edit it with nano .bash_aliases. Add whatever aliases you want.
You won't be able to use your newly added aliases until you open a new terminal session, or reload your profile, --bash login
It's ussually in a file in your home directory, such as .aliases or something.
The question here is:
if I have an alias named 'shortcut,' how do I find out what file is defining that as an alias?
The best and most user-friendly way to do this is this:
sudo grep -roI alias\ nameOfAliasHere=\' /etc/ /home/yourUserName/
-r tells grep to read everything in the directory, and go through the directories recursively, Without it, grep will complain about what you want to do.
-o means print only the part of the line that matches your string
-I suppresses binary files in the results, because those will not help you find out where your alias is
The backslashes mean "treat the next character as part of the string, instead of the normal way you interpret it"
The command will go through everything, including subdirectories, in your home folder and in /etc
If you want to start with the most likely places, just do your home directory:
sudo grep -roI alias\ nameOfAliasHere=\' /home/yourUserName/
To search everywhere it's likely to be defined or mentioned, which can be handy, this:
sudo grep -oIr alias\ ls=\' / --exclude-dir={sys,proc,srv,media,tmp,sbin,bin,boot,mnt,recovery,run,backups,var}
A lot of things like to make the 'ls' command fancier, for example. Check out the comparison below. I also included 'time' at the beginning for kicks:
You can see that there are a couple places outside of your home dir and /etc that have that alias, and it's also defined in both .alias and .bashrc. Personally, I like to throw my custom aliases in a file called .alias, and then tell everything to source it. If you're having trouble with an alias you're trying to define, that's handy. The things you see in the ~/Downloads and .cache directories won't affect your active aliases. Same with the /usr directory.
The file in /etc/skel is used to create home directories for new users, so anything there doesn't affect you. If something shows up in /etc/profile though, that will.
You can also see that the root user has an alias for ls.
In my bash script I need to change current dir to user's home directory.
if I want to change to user's foo home dir, from the command line I can do:
cd ~foo
Which works fine, however when I do the same from the script it tells me:
./bar.sh: line 4: cd: ~foo: No such file or directory
Seams like it would be such a trivial thing, but it's not working. What's the problem here? Do I need to escape the "~" or perhaps missing quotes or something else?
Edit
when I say user I don't mean current user that runs the script, but in general any other user on the system
Edit
Here is the script:
#!/bin/bash
user="foo"
cd ~$user
if username is hardcoded like
cd ~foo
it works, but if it is in the user variable then it doesn't. What am I missing here?
What about
cd $(getent passwd foo | cut -d: -f6)
and
USER=foo
eval cd ~$USER
works, too (foo is the username)
Change it to:
cd $HOME
Actually, I'm not sure why cd ~whatever wouldn't work. I've just tested with a small script and it worked fine:
#!/bin/bash
cd ~sbright
I actually get the same error message that you do when the specified user does not exist on the system. Are you sure (and yes, I know this is one of those is-it-plugged-in questions) that the user exists and has a valid home directory specified?
Edit:
Now that I see what you are actually doing... tilde expansion happens before variable interpolation, which is why you are getting this error.
Is the script going to be run by the user? If it is you can just do:
cd ~
Is there some reason you can't do:
#!/bin/bash
cd /home/$USER
Of course directories aren't in /home on all *nixes, but assuming you know what OS/distro your script is targeted for, you should be able to come up with something that works well enough.