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

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7
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1answer
707 views

bash: per-command history. How does it work?

OK. I have an old G5 running Leopard and a Dell running Ubuntu 10.04 at home and a MacPro also running Leopard at work. I use Terminal.app/bash a lot. On my home G5 it exhibits a nice feature: using ...
13
votes
1answer
998 views

When should I put configurations into .bashrc vs into. .bash_profile?

I was looking at Questin 9152: Why doesn’t my path update now?. Which customizations should go into my ~/.bashrc file vs. into my ~/.bash_profile file?
11
votes
3answers
12k views

Filtering top command output

I'm running a Mac and want to filter the output of the top command for a particular process such that only the PID, COMMAND and %CPU columns are displayed. After getting the PID of the process, I ...
13
votes
3answers
330 views

Reuse text on a bash command

If i'm writing a long command or just typing an extensive file path, is there any that i can "reuse" it with some command shortcut? e.g: 1.cp /home/myuser/really/big/file/here/and/there.png ...
8
votes
5answers
4k views

How to replace vim screen buffer with previous bash activity after quitting?

I'm trying to find out what a bash (or vim) feature is. Here's the scenario. I'm in a bash terminal, then edit something with vim, then exit back to bash. In some terminals, the vim session screen ...
5
votes
4answers
7k views

Using SQLite3 with Cygwin

I'm trying to use sqlite3.exe command shell with a mintty terminal in cygwin. I tried the program from a windows command prompt and it works. When I try to use it from the cygwin mintty terminal it ...
6
votes
2answers
1k views

Creating an alias containing bash history expansion

I often forget to run a command with sudo, so I find myself often typing sudo !! immediately afterwards. I tried aliasing this, but bash chokes on the !! part. Is there some way to represent this ...
5
votes
1answer
3k views

colouring output of ls according to file extension

I am working on some C++ files all of which are in a single folder. When I do ls both the .cpp and the .h files show up in the same colour. Is there a way to tell the bash shell that I want to ...
2
votes
1answer
806 views

How do you remove nested empty directories using a Bash script on Linux?

I want to be able to run a script that will remove all my empty directories. The problem is some of them are nested, i.e. directories that only have empty directories in them, so the script needs to ...
2
votes
1answer
4k views

Messed up $PATH variable in Mac OS X

I did something to my PATH. I was trying to add some new path and now none of the command like open ~/.bash_profile work, and echo $PATH only shows one path which is /Application/Filename. Is ...
1
vote
6answers
659 views

downloading complete web pages (not sites)

I often use offline time (e.g. when on the car/train/plane) to read articles pulled from the web. To store the content, I currently use Firefox's Save Page As. (Note that's not recursively downloading ...
3
votes
2answers
610 views

How to reorder folders? (as displayed in `ls -U`)

I've got a number of unordered folders on a memory stick, which my car stereo shows in order of their real position on the stick (i.e. same as ls -U) What's the easiest way of physically reordering ...
3
votes
3answers
4k views

sudo permission denied

I ran this code: sudo cat <<EOF | sudo sed -e "s,%,$,g" >/etc/init.d/dropbox echo "Hello World" EOF But even though, I get "permission denied", cause you have to be root to make changes ...
3
votes
2answers
10k views

How to use scp in a bash script without specifying password?

I am a bash newbie, and am writing a bash script that will allow transfer of files between two computers. BTW, is there a more secure alternative to scp? Currently, I am doing this manually, by using ...
2
votes
1answer
149 views

Difference between / and // directories in bash OSX

I was working in the bash terminal on my system (OSX 10.8.3 / bash version 3.2.48(1)-release (x86_64-apple-darwin12)) and I accidentally typed "cd //" instead of "cd /" to get back to the root ...
1
vote
1answer
370 views

Terminal new window always shows -bash: Searching: command not found

When open terminal, it always shows -bash: Searching: command not found. It does not affect other functions, just each time, even though open a new terminal window, it still pops up at the top of the ...
1
vote
3answers
264 views

Linux - Protection from ourselves (Root)

I love Linux and everything she stands for; however, unfortunately I grew up with Windows. Thusly so I have learned very bad practices (such as NT Authority will protect me). I have several Linux ...
37
votes
7answers
58k views

Mac OS X keyboard shortcuts for terminal

After googling for some Mac OS X terminal shortcuts, I wanted to find how can I go back characters on a line on the terminal or words or similar. I found ALT + B but it does not work. Do you know ...
107
votes
5answers
44k views

In bash, how do I escape an exclamation mark?

I want to do something like bzr commit -m "It works!". I can sort of escape the exclamation mark by doing bzr commit -m "It works\!". However, then my commit message includes the backslash. How do I ...
29
votes
4answers
19k views

Cygwin fatal error unable to remap.. What does it mean?

When running python in cygwin, I get the following error: 0 [main] python 6140 C:\cygwin\bin\python.exe: *** fatal error - unable to remap \\?\C:\cygwin\lib\python2.6\lib-dynload\time.dll to same ...
54
votes
4answers
22k views

Bash: Spaces in alias name

I am trying to create an aliases in bash. What I want to do is map ls -la to ls -la | more In my .bashrc file this is what I attempted: alias 'ls -la'='ls -la | more' However it does not work ...
26
votes
4answers
29k views

I want to change DPI with ImageMagick without changing the actual byte-size of the image data

In GIMP there is a very simple way to do what I want. I only have the German dialog installed but I’ll try to translate it. I’m talking about going to Picture -> PrintingSize and then adjusting the ...
26
votes
3answers
79k views

Command: sudo su -

I understand what su - does logs you into root with the root environment (as opposed to su which logs you into root with your environment) And I understand what sudo does you are root for one ...
20
votes
3answers
25k views

Environment variables in bash_profile or bashrc?

I have found this question [blog]: Difference between .bashrc and .bash_profile very useful but after seeing the most voted answer (very good by the way) I have further questions. Towards the end of ...
17
votes
3answers
40k views

Copy list of files

I have a list of files separated by spaces in a file list.txt. I'd like to copy them to a new folder. I tried to do: cp `cat list.txt` new_folder but it did not work. How would you do this ? ...
11
votes
5answers
47k views

How to get real-time network statistics in Linux with KB/MB/Bytes format and for specific port or application processID

I used IPTraf, Iftop, vnstat, bwm-ng, ifconfig -a. None of them is helping me to find real-time packets that is getting send/received from my application in KB or MB format. The reason is i am writing ...
30
votes
1answer
6k views

How can I get bash to perform tab-completion for my aliases?

I have a bunch of bash completion scripts set up (mostly using bash-it and some manually setup). I also have a bunch of aliases setup for common tasks like gco for git checkout. Right now I can ...
15
votes
4answers
3k views

A command before every bash command

Does anyone know a mean of putting a 'time' command before every command in a bash session?
34
votes
8answers
20k views

Rename a group of files with one command

If I have a group of files with a .htm extention, how can I rename them all to .html? mv *.htm *.html does not work.
27
votes
1answer
4k views

How do I reload .inputrc using a bash script?

This question explains how to reload .inputrc using C-x C-r. But how would one reload it using commands in a bash script?
38
votes
7answers
41k views

How can I do a recursive find and replace from the command line?

Using a shell like bash or zshell, how can I do a recursive 'find and replace'? In other words, I want to replace every occurrence of 'foo' with 'bar' in all files in this directory and its ...
22
votes
7answers
25k views

In bash, how to sort strings with numbers in them?

If I have these files in a directory cwcch10.pdf cwcch11.pdf cwcch12.pdf cwcch13.pdf cwcch14.pdf cwcch15.pdf cwcch16.pdf cwcch17.pdf cwcch18.pdf cwcch1.pdf cwcch2.pdf cwcch3.pdf cwcch4.pdf cwcch5.pdf ...
36
votes
4answers
3k views

Difference between “a=b” and “export a=b” in bash

What's the difference between: a=b and export a=b In bash? I understand that they both define environment variables, but I don't fully understand the difference.
32
votes
4answers
96k views

How to gzip multiple files into one gz file?

I have 100 files: cvd1.txt cvd2.txt ... cvd100.txt How to gzip 100 files into one .gz file so that after I gunzip it, I should have cvd1.txt, cvd2.txt ... cvd100.txt separately? Thanks for your ...
18
votes
4answers
14k views

Newlines in sed on Mac OS X

I find that \n doesn't work in sed under Mac OS X. Specifically, say I want to break the words separated by a single space into lines: # input foo bar I use, echo "foo bar" | sed 's/ /\n/' But ...
17
votes
8answers
44k views

Creating and formating a partition using a bash script

Is there any way to create and format a partition using a bash script? I think it can be done with fdisk but I don't know how to feed commands from the bash script into the fdisk shell then exit the ...
18
votes
1answer
4k views

Why do we have login, non-login, interactive, and non-interactive bash shells?

So the bash man pages explain what login and interactive shells are: A login shell is one whose first character of argument zero is a -, or one started with the --login option. An ...
17
votes
8answers
28k views

Sudo - is there a command to check if I have sudo and/or how much time is left?

(Originally posted on Stack Overflow. They suggested I try here instead. Here's the original post: ...
20
votes
4answers
5k views

Equivalent/Alternatives for Alt+Dot in Mac

One thing i miss from the Linux shell is the Alt+Dot shortcut. What it does is insert the last argument of the previous command. It appears to be a trivial technique, but it's really useful. i.e. if ...
13
votes
2answers
16k views

(reverse-i-search) in bash

I usually end up using CTRL+r for (reverse-i-search), however, sometimes I pass the command that I was looking for; if I do again a (reverse-i-search) it doesn't find it anymore. I assume that the ...
17
votes
7answers
9k views

How to retrieve the absolute path of an arbitrary file from the OS X

I'm looking for a simple command that can be used within Bash to find the absolute and canonicalized path to a file on an OS X (similar to `readlink -f' under Linux). The following sample bash ...
17
votes
5answers
18k views

Writing “tail -f” output to another file

As a continuation from my last post where I have used grep & tail -f to find occurences of "rare" events. I would like to record this in another file. I've tried turning tail -f log.txt | ...
12
votes
4answers
33k views

How can I pipe output of ffmpeg to ffplay?

How can I pipe the output of ffmpeg to ffplay? At the moment I use a workaround in bash : mkfifo spam (ffplay spam 2> /dev/null &) ; capture /dev/stdout | ffmpeg -i - spam
9
votes
2answers
8k views

Finding all symbolic and hard links to a file on UNIX

If I have a specific file in a UNIX filesystem, is there a way to use bash to find all links to that file, both symbolic and hard? If I need different commands for each, what are they?
28
votes
3answers
11k views

Bash command to focus a specific window

Is there a way, in bash command line, to give focus to a specific window of a running process. Assume I know the process' name, number, and anything else I need. For instance, if I have a single ...
27
votes
2answers
19k views

Avoid unwanted path in Zip file

I'm making a shell script to package some files. I'm zipping a directory like this: zip -r /Users/me/development/something/out.zip /Users/me/development/something/folder/ The problem is that the ...
18
votes
6answers
44k views

Run part of a bash script as a different user

Is there a way to make part of a script run as a different (non-root) user? If it helps , the part to be run as a different user occurs at the end of the script Edit : OS -> Ubuntu 9.04
17
votes
4answers
7k views

Custom bash tab completion

I have my custom console utility cooltool with list of options fooOption barOption What should I do to able bash autocomplete the options by pressing the tab key? I mean the user typed $ ...
11
votes
1answer
9k views

How can I see a timestamp for when a command was executed using history?

I'd like to check at what time/date a command in bash history was executed. Is this possible?
10
votes
4answers
5k views

Open hidden configuration files without using Terminal

I made some changes to my .profile which corrupted the Terminal app. I can launch terminal but I no longer get a prompt. I can't show hidden files in order to delete the .profile or .bashrc files. ...