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1500 questions
104
votes
8 answers
Connecting to wifi network through command line
I am trying to connect to my WEP network just using the command-line (Linux).
I run:
sudo iwconfig wlan0 mode Managed essid 'my_network' key 'xx:xx:... hex key, 26 digits'
Then I try to obtain an IP with
sudo dhclient -v wlan0
or
sudo dhclient…
Jayson Condor
- 1,041
104
votes
2 answers
What do the symbols displayed by ls -F mean?
I noticed that if I run ls -F on a directory, some of the entries have a * or a @ after them.
spuder@ubuntu:~$ ls -F /sbin
acpi_available* getpcaps* lvmconf* ntfscp* start-stop-daemon*
agetty* getty* …
spuder
- 18,053
104
votes
8 answers
How to install apt-get or YUM on Mac OS X
I want to use either of apt-get or yum.
How to install them and make them successful running?
Karan-41317
- 1,151
104
votes
7 answers
Does LVM impact performance?
I have to migrate a few servers to Linux, and one important aspect that I need to evaluate is that my new host system must have elastic storage capacity. Naturally, doing some basic research, I came across LVM.
Is there any performance penalty for…
Pablo
- 2,545
- 6
- 27
- 24
104
votes
4 answers
How can swapoff be that slow?
Somehow I happened to swap out 14 GB of memory. After having killed the culprit, I have tons of free memory again, so I thought I could bring in the important data again. So with 5 GB out of 32 GB used and 14 GB of swap space used, I ran swapoff…
maaartinus
- 5,059
104
votes
1 answer
jq - select an attribute beginning with a string
input json:
[
{
"id": "89",
"hostname": "abcd"
},
{
"id": "89",
"hostname": "babcd"
}
]
How to modify below filter to get on output only hostname beginning with "abcd"?
$ jq -r '.[]|select(.hostname | contains("abcd"))'…
Chris
- 4,091
104
votes
6 answers
Can I set up system mail to use an external SMTP server?
Is it possible to set up system mail on a linux box to be sent via a different smtp server - maybe even with authentication? If so, how do I do this?
If that's unclear, let give an example. If I'm at the command line and type:
cat body.txt | mail -s…
cwd
- 45,389
104
votes
2 answers
List of terminal generated signals (eg Ctrl-C -> SIGINT)
Where can I find a complete list of the keyboard combinations which send signals in Linux?
Eg:
Ctrl+C - SIGINT
Ctrl+\ - SIGQUIT
Tom Hale
- 30,455
104
votes
11 answers
Eject USB drives / eject command
I know that the eject command can be used to eject almost any hardware component attached, but can it be used to eject USB drives?
Is it possible to eject USB drives and external HDD's with the eject command?
Joe Barr
- 1,327
104
votes
3 answers
Git submodule shows new commits, submodule status says nothing to commit
In a git repository, I have set up my .gitmodules file to reference a github repository:
[submodule "src/repo"]
path = src/repo
url = repourl
when I 'git status' on this repo, it shows:
On branch master
Your branch is up-to-date with…
Catherine Holloway
- 1,145
104
votes
3 answers
What are "session leaders" in `ps`?
What are session leaders, as in ps -d which selects all processes except session leaders?
its_me
- 13,959
104
votes
4 answers
What is difference between GTK and QT applications?
Many packages are available in both GTK and QT versions.
What's the difference between them?
Is there any difference in
performance or working method?
Pandya
- 24,618
104
votes
6 answers
As root, how can I list the crontabs for all users?
I have a script being run automatically that I can't find in the crontab for the expected users, so I'd like to search all users' crontabs for it.
Essentially I want to run a crontab -l for all users.
Highly Irregular
- 2,525
104
votes
16 answers
sort but keep header line at the top
I am getting output from a program that first produces one line that is a bunch of column headers, and then a bunch of lines of data. I want to cut various columns of this output and view it sorted according to various columns. Without the headers,…
jonderry
- 2,089
104
votes
6 answers
Using while loop to ssh to multiple servers
I have a file servers.txt, with list of servers:
server1.mydomain.com
server2.mydomain.com
server3.mydomain.com
when I read the file line by line with while and echo each line, all works as expected. All lines are printed.
$ while read HOST ; do…
Martin Vegter
- 358
- 75
- 236
- 411