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1500 questions
82
votes
3 answers
Why doesn't cp have a progress bar like wget?
Please note that I don't ask how. I already know options like pv and rsync -P.
I want to ask why doesn't cp implement a progress bar, at least as a flag ?
Lamnk
- 1,450
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82
votes
4 answers
What could DUP mean when using ping?
What could DUP mean when using ping?
LanceBaynes
- 39,295
- 97
- 250
- 349
82
votes
3 answers
How does /usr/bin/env know which program to use?
When I use the shebang #!/usr/bin/env python to run a script, how does the system know which python to use? if I look for a python bin path in the environment variables I find nothing.
env | grep -i python
tMC
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- 1
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81
votes
2 answers
What do square brackets mean without the "if" on the left?
As far as I know, square brackets are used to enclose an expression usually in if else statements.
But I found square brackets being used without the "if" as follows:
[ -r /etc/profile.d/java.sh ] && . /etc/profile.d/java.sh
in the following…
supertonsky
- 913
- 1
- 7
- 6
81
votes
8 answers
rsync all files of remote machine over SSH without root user?
I have this command to backup a remote machine. The problem is that I need root rights to read and copy all files. I have no root user enabled for security reasons and use sudo the Ubuntu way. Would I need some cool piping or something to do…
redanimalwar
- 1,027
- 1
- 10
- 13
81
votes
2 answers
Command line: <<< instead of <<
Why is the command md5sum <<< 'ddd'
(output: d6d88f2e50080b9602da53dac1102762 -)
right, and md5sum << 'ddd' not?
What does <<< mean?
Jean Paulus
- 811
- 1
- 7
- 3
81
votes
8 answers
Best way to remove bytes from the start of a file?
Today I had to remove the first 1131 bytes from an 800MB mixed text / binary file, a filtered subversion dump I'm hacking for a new repository. What's the best way to do this?
To start with I tried
dd bs=1 skip=1131 if=filtered.dump…
Rup
- 913
- 1
- 7
- 11
81
votes
5 answers
Bash: How to read one line at a time from output of a command?
I am trying to read the output of a command in bash using a while loop.
while read -r line
do
echo "$line"
done <<< $(find . -type f)
The output I got
ranveer@ranveer:~/tmp$ bash test.sh
./test.py ./test1.py ./out1 ./test.sh ./out ./out2…
RanRag
- 5,675
- 6
- 20
- 15
81
votes
1 answer
vi - How go to line N?
In vi editor how do I go to a particular line ?
For example if I open a file named file.py is there an option for open the file at a particular line or can I open my file and then go to line with keybord shortcut ?
Antoine Subit
- 2,019
- 2
- 11
- 10
81
votes
4 answers
No sha256sum in MacOS
I tried to use sha256sum in High Sierra; I attempted to install it with MacPorts, as:
sudo port install sha256sum
It did not work.
What to do?
Rui F Ribeiro
- 55,929
- 26
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81
votes
5 answers
Remove unused packages
I have installed some rpm package on my Fedora 17. Some packages had a lot of dependencies.
I have removed some packages but I forgot remove unused dependencies with yum remove.
How can I do that now?
mudlee
81
votes
2 answers
How to create backup from symbolic links?
I have a directory with symbolic links to other directories. I want to archive the symbolic links, not as links but as archives containing the files of directories they refer to, using tar command. How can I do this?
hknik
- 2,324
- 3
- 25
- 26
81
votes
4 answers
How to mount a disk image from the command line?
I know how to mount a drive that has a corresponding device file in /dev, but I don't know how to do this for a disk image that does not represent a physical device and does not have an analogue in /dev (e.g. an ISO file or a floppy image). I know…
user628544
- 1,495
- 2
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- 16
81
votes
13 answers
Why write an entire bash script in functions?
At work, I write bash scripts frequently. My supervisor has suggested that the entire script be broken into functions, similar to the following example:
#!/bin/bash
# Configure variables
declare_variables() {
noun=geese
count=three
}
#…
Doktor J
- 2,622
- 2
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- 18
81
votes
3 answers
What's the quickest way to find duplicated files?
I found this command used to find duplicated files but it was quite long and made me confused.
For example, if I remove -printf "%s\n", nothing came out. Why was that? Besides, why have they used xargs -I{} -n1?
Is there any easier way to find…
The One
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