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1500 questions
296
votes
2 answers
How to write startup script for Systemd?
I have 2 graphics cards on my laptop. One is IGP and another discrete.
I've written a shell script to to turn off the discrete graphics card.
How can I convert it to systemd script to run it at start-up?
Sharique
- 3,183
294
votes
7 answers
How to go to the previous working directory in terminal?
In terminal, how can I define a key to go to the previous directory which I was in when changing directory with the cd command?
For example, I'm in /opt/soft/bin and I cd into /etc/squid3 and I want to get back to the first directory.
Hojat Taheri
- 5,056
293
votes
9 answers
How can I display the contents of a text file on the command line?
I would like to display the contents of a text file on the command line. The file only contains 5-6 characters. Is there an easy way to do this?
Sam Weinberg
- 3,043
293
votes
10 answers
How to know if a disk is an SSD or an HDD
I want to know whether a disk is a solid-state drive or hard disk.
lshw is not installed. I do yum install lshw and it says there is no package named lshw. I do not know which version of http://pkgs.repoforge.org/lshw/ is suitable for my CentOS.
I…
user4951
- 10,519
293
votes
2 answers
Recursively delete all files with a given extension
I want to delete all *.o files in a directory and its sub-directories. However, I get an error:
sashoalm@aspire:~/.Workspace.OLD$ rm -r *.o
rm: cannot remove `*.o': No such file or directory
On the other hand, rm *.o works, but it's not recursive.
sashoalm
- 5,820
292
votes
29 answers
SSH tunneling error: "channel 1: open failed: administratively prohibited: open failed"
When I open this ssh tunnel:
ssh -nXNT -p 22 localhost -L 0.0.0.0:8984:remote:8983
I get this error when trying to access the HTTP server running on localhost:8984:
channel 1: open failed: administratively prohibited: open failed
What does this…
Neil
- 3,462
290
votes
6 answers
What's the difference between $(stuff) and `stuff`?
There are two syntaxes for command substitution: with dollar-parentheses and with backticks.
Running top -p $(pidof init) and top -p `pidof init` gives the same output. Are these two ways of doing the same thing, or are there differences?
tshepang
- 65,642
289
votes
8 answers
How to determine where an environment variable came from?
I have a Linux instance that I set up some time ago. When I fire it up and log in as root there are some environment variables that I set up but I can't remember or find where they came from.
I've checked ~/.bash_profile, /etc/.bash_rc, and all…
Joel
- 2,993
289
votes
12 answers
How do I convert an epoch timestamp to a human readable format on the cli?
How do I convert an epoch timestamp to a human readable format on the cli? I think there's a way to do it with date but the syntax eludes me (other ways welcome).
xenoterracide
- 59,188
- 74
- 187
- 252
288
votes
2 answers
how can I recursively delete empty directories in my home directory?
Possible Duplicate:
How to remove all empty directories in a subtree?
I create directories very often, scattered over my home directory, and I find it very hard to locate and delete them.
I want any alias/function/script to find/locate and delete…
Santosh Kumar
- 3,893
287
votes
3 answers
Most efficient method to empty the contents of a file
I am aware of three methods to delete all entries from a file.
They are
>filename
touch filename1
filename < /dev/null
Of these three I abuse >filename the most as that requires the least number of keystrokes.
However, I would like to know which…
debal
- 3,704
286
votes
16 answers
How do I find out what hard disks are in the system?
I need to know what hard disks are available, including ones that aren't mounted and possibly aren't formatted. I can't find them in dmesg or /var/log/messages (too much to scroll through). I'm hoping there's a way to use /dev or /proc to find out…
xenoterracide
- 59,188
- 74
- 187
- 252
285
votes
7 answers
Find out current working directory of a running process?
What command(s) can one use to find out the current working directory (CWD) of a running process? These would be commands you could use externally from the process.
slm
- 369,824
285
votes
18 answers
How do you sort du output by size?
How do you sort du -sh /dir/* by size? I read one site that said use | sort -n but that's obviously not right. Here's an example that is wrong.
[~]# du -sh /var/* | sort -n
0 /var/mail
1.2M /var/www
1.8M /var/tmp
1.9G /var/named
2.9M …
xenoterracide
- 59,188
- 74
- 187
- 252
285
votes
10 answers
How can I send stdout to multiple commands?
There are some commands which filter or act on input, and then pass it along as output, I think usually to stdout - but some commands will just take the stdin and do whatever they do with it, and output nothing.
I'm most familiar with OS X and so…
cwd
- 45,389