Bash is a free shell for Unix-like operating systems from the GNU Project.

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3answers
8k views

remove first line in bash

Do you have a method to quickly remove the first line of a file in bash shell ? I mean using sed or stuff like that.
6
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6answers
3k views

What is the difference between “Shell” and “Terminal”? [duplicate]

I am fairly new to Ubuntu and I am loving it! But I don't quite understand the difference between the shell and the terminal. Can any one explain? Someone told me that a terminal is just a "tool" to ...
5
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2answers
183 views

Making custom, single-character directory mappings like ~ > $HOME

We all know that ~ maps to $HOME or /home/user. Is it possible to make other mappings like this on other characters (@,_)? A possible workaround I thought of was to use variables (which require at ...
5
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2answers
1k views

How can I run a different command but with the same arguments?

For example, I edit and then run the same source. vim arbit.py python arbit.py I know I could run it from within vim, but I want a general solution on Bash. I keep finding situations where I reuse ...
5
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2answers
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Linux: How to automatically run commands on SSH login?

Whenever I login to my Linux server I'd like to have several commands run automatically (set some variables, change location, etc.) This needs to be done on user login, not on system start. How can ...
5
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1answer
7k views

Counting occurrences in first column of a file

We have this file: 1 2 1 3 1 2 3 3 52 1 52 300 and 1000 more. I want to count the number of times each value occurs in the first column. 1 3 3 1 52 2 This means we saw 1 three times. How ...
4
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1answer
5k views

Where to store bash scripts that all users may execute on Debian?

I have many bash scripts on my server, that all users may use. but it seems the location /usr/local/sbin is not the best place. I don't want to use the home directory of the users, cause ...
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5answers
25k views

No bashrc file in my home directory

Here is what I noted down from my lecture: Find file .bashrc in your home directory do vi .bashrc When you put an application folder somewhere, make sure that its address is in the path variable. ...
3
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2answers
7k views

change default shell from zsh to bash

I'm trying to change my default shell in RHEL5 from zsh to bash. I tried to the methods mentioned in this thead. By typing sudo /usr/bin/chsh -s /bin/bash, the system says sudo: /usr/bin/chsh: ...
35
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5answers
257k views

How can I resolve the error “cannot execute binary file”?

When I login using SSH, all I can see is this... -bash: /usr/bin/id: cannot execute binary file -bash: [: : integer expression expected I couldn't do anything in here. Commands such as halt, ...
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1answer
3k views

Why does wget give an error when executed with sudo, but works fine without?

I tried the following command: $ wget -q --tries=10 --timeout=20 --spider http://google.com (From this SO post. I want to check my internet connection in bash.) I get following output: Spider ...
19
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2answers
65k views

.profile in Mac OS X?

I have set my terminal preferences to execute: set -o vi at startup. The problem is I don't get that command executed when open a new terminal tab. Is there something like .profile in OS X where ...
14
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9answers
11k views

How do I copy file named starting with a dot?

I am trying to copy all files under directory A to directory B. All files under directory A are starting with dot, for example: A/.a A/.b A/.c which I found if I use: cp A/* B, always get error: ...
14
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3answers
3k views

How can I add a command to the Bash history without executing it?

Every now and then it would be useful to add a command directly to the history in Bash without actually executing it. So far the closed thing I have found is adding a # in front of it and hitting ...
13
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3answers
27k views

How can I “grep” recursively filtering the name of the files I want with wildcards?

When I want to perform a recursive grep search in the current directory, I usually do: grep -ir "string" . But that command searches inside all kinds of files, including binary files (pictures, ...
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4answers
3k views

BASH history truncated to 500 lines on each login

For some reason, I cannot get my system to keep my BASH history after a reboot. Here are the relevant sections of my ~/.bashrc: shopt -s histappend PROMPT_COMMAND='history -a; updateWindowTitle' ...
9
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8answers
1k views

Save me from gibberish terminal

While logged in to a remote ssh session, sometimes I do cat to the wrong file (a binary or a diretory) and the display converts to gibberish. The only way out is to close the terminal and open a new ...
9
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6answers
4k views

bashrc: how to know X window is available or not?

There is a part in my ~/.bashrc, which sets $EDITOR to be gvim. It works fine when I am in X window. However, if I ssh to my workstation (from another workstation) gvim starts to complain "cannot open ...
9
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2answers
2k views

Is it possible to run a bash script in a sort of sandbox?

Our product has a need to execute an unknown bash script on a delicate server in order to achieve a certain goal. This bash script is user-supplied. We are interested in ensuring that only specific ...
7
votes
5answers
23k views

How do I run a script in the background and leave it running when I log out? [duplicate]

Possible Duplicate: Leave bash script running on remote terminal while not logged in? I have a bash script that runs Gaussian, a chemical structure calculator, which spends a couple days ...
7
votes
2answers
3k views

Smart tab completion (for directories)?

Are there shell versions that have a more intelligent tab completion? I'd like to be able to type cd foo-<TAB> Then it would show me the possible completions along with numbers that I can ...
7
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2answers
8k views

Monitor a Folder OSX for file changes then run a bash script [duplicate]

Possible Duplicate: Watch Filesystem in Real Time on OS X and Ubuntu I'm looking for a efficient method to monitor a local directory in OSX and if any files have been changed in that directory ...
6
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3answers
11k views

Can't edit /etc/profile on my mac

In terminal, I do this: sudo vi /etc/profile But I get a read-only version. I've never not been able to edit anything as a super user- What's going on?
6
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5answers
4k views

How to read one line from `tail -f` through a pipeline, and then terminate?

I would like to follow changes to a file via tail -f and then print out the first line that matches a grep command before terminating. What's the simplest way to do this? So far I've been ...
6
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3answers
7k views

How to redirect to stdin of a running bash shell?

Theoreticly, if I know the pid of the bash shell which is running, I can run a cat whose stdout is redirected to the stdin of that shell. It seems to be as if I type something on that shell. ...
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4answers
3k views

Accessing the output of a Bash pipe with 'read'

I'm trying to pipe some data from a Bash pipe into a Bash variable using the read command, like this: $ echo "Alexander the Grape" | read quot $ echo $quot $ But quot is empty. Some Googling ...
5
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6answers
326 views

Linux/Unix in Windows

What would be the best way to get the full-blown Unix/Linux bash inside Windows? I don't mean the Virtual Machine, but rather only the terminal with mounted NTFS drives. This way I could use the ...
5
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3answers
2k views

Alert after long running shell script

When I have wait for slow commands (operations on large databases for example), I start doing something else and often don't notice for a long time that it has finished, wasting valuable time. I am ...
5
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1answer
4k views

Bash, how to globally fix ^H and ^? backspace problems

I'd like to fix this frequent problem where the shell on a remote server thinks my terminal's backspace key is ^? and sometimes it thinks it is ^H, and happens to be incorrect and outputs the wrong ...
5
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2answers
4k views

How to persist bash history?

I don't know if this is expected, but my history is not saved across sessions. This is to say, if I close the window, then when I open it again, the history is empty. How can I persist it across ...
4
votes
2answers
4k views

Redirect stdout to a file when process is run in background

How can I redirect the stdout of a program to a file when it's run in the background? I have a program that generates output every second. When I run it normally and redirect to a file, the output ...
4
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2answers
3k views

rsync N newest files in a directory

What would be the easiest way to go about rsyncing the n newest files in a directory to a remote server?
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1answer
2k views

Move running process to background

How do you move a running process to the background? For example, type the command sleep 60 on the command line and try moving that process to the background.
4
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1answer
555 views

Function which overrides bash command

Is it possible to call a bash command which has been overridden with a function? I'd like to make pushd with no arguments alias to pushd . otherwise get normal behaviour. I've tried pushd(){ if [ ...
3
votes
2answers
2k views

Program to check/look up UTF-8/Unicode characters in string on command line?

I've just realized I have a file on my system; it lists normally: $ ls -la TΕSТER.txt -rw-r--r-- 1 user user 8 2013-04-11 18:07 TΕSТER.txt $ cat TΕSТER.txt testing ... yet, it crashes a piece of ...
3
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7answers
11k views

How to recursively download an entire web directory?

i have a web directory that has many folders and many sub folders containing files. i need to download everything using wget or bash.
3
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2answers
10k views

How list file by range of date?

I would like to list files with 3 days years old. I found this one at stackoverflow: find . -type f -printf "%-.22T+ %M %n %-8u %-8g %8s %Tx %.8TX %p\n" | sort | cut -f 2- -d ' ' | grep 2012 But I ...
2
votes
1answer
814 views

Bash autocomplete paths “through” environmental variables

I used to be able to type cd $home/p hit the tab key and the command would change to cd /home/phill Now it doesn't. When cd'ing to a directory based on an environmental variable, I'm "flying ...
2
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3answers
750 views

What escape code do I need in PS* to make sure terminal is back in normal settings on shell prompt?

Sometimes I accidentally cat some binary data; sometimes some ncurses program crash - for plenty of reasons terminal can end up in bad state, requiring manual reset. This is happening too often. Such ...
2
votes
4answers
151 views

Manage a few Linux servers at once

I have a small cluster that consists of a few Linux nodes. There's a shared NFS, and I have the same user account with shared SSH keys on all nodes, but other than that each node has it's-own file ...
1
vote
1answer
13k views

-bash: ls: command not found at Terminal on Mac OS X

I need to start using GIT for my projects from now on and I need to use some UNIX commands. but no matter what I do, I always receive "command not found" error. I installed MacPorts, but still cant ...
15
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2answers
3k views

How to prevent clearing of terminal output when I “exit” an SSH session?

This is the situation: I open a terminal in Ubuntu, and do ssh host-1, which works as expected. From host-1, I do ssh host-2, which again works fine and connects me to host-2. From host-2 I do, for ...
13
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4answers
5k views

Understanding pipe in bash

I dont quite understand how pipes work in bash. I know that it takes an output from one command as the input in another command. What an output is i can get because it's what the command prints out ...
12
votes
4answers
16k views

Copy files in Linux, avoid the copy if files do exist in destination

I need to copy a /home/user folder from one hard disk to another one. It has 100,000 files and around 10G size. I use cp -r /origin /destination sometimes I get some errors due to broken links,...
12
votes
5answers
19k views

What does the linux pipe symbol “|” do? [duplicate]

Here is a command that sorts files in a folder in reverse order ls | sort -r What does the | symbol in that command do? What I'm really looking for here is high level (easy to understand) ...
12
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1answer
32k views

How to permanently add current directory to PATH in Linux? [duplicate]

Possible Duplicate: Add folder to PATH I want to a add a directory to my bash to search in, and I am using the $PATH=.... it works however when I open a new command window it is not there. ...
10
votes
3answers
7k views

Spawn New Cygwin Window from Within Cygwin

I can't figure out how to launch a new Cygwin session from within Cygwin, similar to launching a new terminal from within bash with: gnome-terminal It's probably easy but I am missing something. ...
9
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6answers
8k views

Clear stdin before reading

I have the following bash script: # do some time consuming task here read -p "Give me some input: " input Now as you might have guessed, if a user presses some random keys during the "time ...
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3answers
8k views

Gnome: Change title of current terminal from bash command line

I know there are options to start a new terminal with a specified title, and that is is possible to change the title from a terminal using the menu: 'Terminal' -> Set Title. However, I want to change ...
8
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4answers
882 views

Running `exec` with a Bash built-in

I defined a shell function (let's call it clock), which I want to use as a wrapper to another command, similar to the time function, e.g. clock ls -R. My shell function performs some tasks and then ...