The command-line is the interactive interface to your shell.

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5
votes
1answer
4k views

How to grep the output of cURL?

I need to retrieve the expiry date of an SSL cert. The curl application does provide this information: $ curl -v https://google.com/ * Hostname was NOT found in DNS cache * Trying ...
61
votes
9answers
18k views

How do I delete a file whose name begins with “-” (hyphen a.k.a. dash or minus)?

How do you remove a file whose filename begins with a dash (hyphen or minus) -? I'm ssh'd into a remote OSX server and I have this file in my directory: tohru:~ $ ls -l total 8 -rw-r--r-- 1 me ...
0
votes
2answers
37 views

Auto Delete Inactive files after x

Is there a way I could delete certain folders after x amount of days of inactivity? I was thinking of using cron but that wouldn't take the inactivity part into consideration. Is there any Debian ...
4
votes
2answers
76 views

Expand wild cards in command before executing it

Suppose I want to type something like this: rm build/* tmp/* I am about to run it but I want to expand the wildcards before executing so I can verify what is about to happen. How can I do this? ...
113
votes
14answers
50k views

How to have tail -f show colored output

I'd like to be able to tail the output of a server log file that has messages like: INFO SEVERE etc, and if it's SEVERE, show the line in red; if it's INFO, in green. What kind of alias can I ...
1
vote
3answers
131 views

Bash long string, no word splitting?

I want to tidy up some script with long commands, so that for example: { somecheck || somecomand "reallyreallyreallyreallyreallyreallylongstring" } &> /dev/null & becomes something like: ...
1
vote
0answers
51 views

Can't run php cli at webuser but will run as root

I am running a Magento application on a Nginx server. nginx + php-fpm running as webuser:www There are some function in the shell directory of Magento which run fine as root and the import run fine ...
4
votes
4answers
482 views

How to capture command line input into logfile and execute it at the same time?

Let's say I issue some commands on the command line: #capture what follows $ echo "foo" foo # don't capture $ echo "bing" bing # capture again $ echo "bar" bar How can I log commands selectively ...
0
votes
1answer
81 views

-bash: auto: command not found

I'm going to config my network interfaces and run this command: auto eth0 but it returns -bash: auto: command not found. It seems I've missed something which I don't know. Any idea? What should I ...
7
votes
6answers
13k views

How to output only file names (with spaces) in ls -Al?

I should echo only names of files or directories with this construction: ls -Al | while read string do ... done ls -Al output : drwxr-xr-x 12 s162103 studs 12 march 28 12:49 personal ...
9
votes
2answers
281 views

How to access the second argument from the last command in the history ?

I am starting to learn some Regex, therefore I use this command repeatedly: grep pattern /usr/share/dict/american-english Only the part with pattern changes, so I have to write the long expression ...
0
votes
3answers
42 views

is it possible to create a macro-like user defined shell command?

Is it possible to run a single shortened command that would in turn initiate multiple longer to type commands? for instance, $ kontact & rekonq when passed to my terminal opens two ...
0
votes
1answer
34 views

how to open sets of programs simultaneously with command line

I recently learned here how to open a program from the command line. my question is, how can i make a set of programs open simultaneously with one command entered?
3
votes
1answer
121 views

Initiating programs from command line

Silly question, but hopefully some easy rep for someone. I am new to the linux/open source community, and I find it very feature rich, but often confusing. I am trying to configure a speedy ...
7
votes
3answers
3k views

Why a long delay after command not found?

Often when I mistype a command such as ls (e.g. I hit ENTER before I type 's') there is a long (~2s) delay after the terminal displays: bash: l: command not found... I can understand the reasons ...
1
vote
2answers
40 views

Merge lines in file together from regex to “lineify” multiline log log files

Stadard unix command line tools (grep, cut, sed etc.) all work one line at a time. And nearly always, this is great. However I am trying to parse some postgresql slow query logs. Each entry has some ...
1
vote
1answer
66 views

Running every command through another

I'm setting up a system in which any external command that does something with real effect must be crypthographically signed before before the system will execute them. The restrictions are in place ...
2
votes
2answers
581 views

How to permanently enable scl CentOS 6.4?

I installed a newer version of devtoolset (1.1) and was wondering how I would go about permanently setting these to be default. Right now, when I ssh into my server running CentOS, I have to run this ...
-1
votes
1answer
45 views

Replace mutiple strings with different values in a file using unix [duplicate]

I have a file in which the data is like below, 01,0000000,xxxxxxx/ 02,xxxxxxxx,yyyyyy/ 03,test1,41203016,,/ 01,0000000,xxxxxxx/ ...
17
votes
6answers
7k views

How to display numbers in reverse order using seq(1)?

I have iterate over numbers in various order. I am able to display them in increasing order, even with steps like: $ seq --separator="," 1 10 1,2,3,4,5,6,7,8,9,10 $ seq --separator="," 1 2 10 ...
1
vote
1answer
50 views

How to copy a directory with only specified type of files?

I got a git directory with plenty of python files(and some special file like .git). I'd like to copy only these python files to another directory with the directory structure unchanged. How to do ...
4
votes
4answers
3k views

Get list of subdirectories which contain a file matching a string

How can I get a list of the subdirectories which contain a file matching a particular string? More specifically, I am looking for directories which contain a file with the letter 'f' somewhere ...
0
votes
1answer
40 views

What is the email matching regex in basic regex for grep?

I created a text file and put some email addresses in it. Then I used grep to find them. Indeed it worked: # pattern="^[a-zA-Z0-9]+@[a-zA-Z0-9]+\.[a-z]{2,}" # grep -E $pattern regexfile but only as ...
4
votes
1answer
3k views

Convert a folder of images into a multi-page pdf file using command line tools?

I have a folder with 100 jpg images. I want to convert these images into a multi-page pdf file, with all the images (cropped to A4 size). They are already in the correct rotation. Which tools should ...
35
votes
11answers
22k views

Markdown Viewer

I found a file formatted with Markdown. Could you guys suggest what viewer that I could use to view this type of files? Hopefully one without gui (if it's possible) Update I was actually looking for ...
0
votes
0answers
29 views

command line tool group chat utility under linux

I am working on mac osx Yosemite. I want to reach to a user under a certain IP address. (It might be local network or thru internet). I want to do it thru terminal using the default tools that ...
3
votes
3answers
128 views

extract from line to line and then save to separate file

I tried my luck with grep and sed but somehow I don't manage to get it right. I have a log file which is about 8 GB in size. I need to analyze a 15 minute time period of suspicious activity. I ...
1
vote
1answer
58 views

cfdisk or fdisk?

While reading the man page for fdisk I came across this interesting text: There are several *fdisk programs around. Each has its problems and strengths. Try them in the order ...
8
votes
5answers
585 views

What's the best way to take a segment out of a text file?

What's a good way of extracting say, lines 20 -45 out of a huge text file. Non-interactively of course!
17
votes
2answers
2k views

How did this '&' at the end of my command, make the script SO fast?

While solving some CTF challenges online, I came across a situation where I needed to bruteforce a server. This is the code I wrote: #!/bin/bash for i in {0..9}{0..9}{0..9}{0..9} do echo ...
22
votes
6answers
57k views

Is there a way to see details of all the threads that a process has in Linux?

For Windows, I think Process Explorer shows you all the threads under a process. Is there a similar command line utility for Linux that can show me details about all the threads a particular process ...
0
votes
1answer
43 views

How to shutdown Linux parted magic from terminal?

Once in a while I have to use parted magic to restore superblocks. I tried to execute in the terminal: shutdown -h now telinit 0 Both did not work, what else might be possible to shutdown Linux via ...
2
votes
2answers
74 views

Can I recover my .bash_profile from an open Terminal tab?

I'm actually using a Macbook Pro, and am quite new to non-Windows OS' (I know, for shame!), and I've made the mistake of overwriting my bash profile, instead of appending to it... (n00b!). What I do ...
2
votes
1answer
84 views

how to get the full command line args passed to a process on unix/linux systems? [duplicate]

I am looking for a reliable way to get the full command line args passed to a process even when these are very long. I do know about ps -f -p <pid> and /proc/<pid>/cmdline, both of which ...
1
vote
3answers
156 views

How to perform grep onto the output of ldd properly ?

# ldd /usr/bin/ffmpeg linux-vdso.so.1 => (0x00007ffffc1fe000) libavfilter.so.0 => not found libpostproc.so.51 => not found libswscale.so.0 => not found ...
2
votes
1answer
48 views

How to tell xargs which argument to choose ? [duplicate]

When xargs redirects the first commands output into the second command's argument and there is no choice about which argument for which element of the output, then there is only one way, for instance: ...
12
votes
6answers
21k views

Delete 100 lines from vi editor using single command

I am using Ubuntu and trying to delete all 100 lines from vi editor but I got interview question of doing this in one command.
2
votes
2answers
752 views

How to enable double tab autocompletion list in csh?

I've worked in Linux before where when I press tab it autocompletes until it becomes ambiguous. If I pressed tab twice at that point it would give me a list of all possible completions. My current ...
1
vote
1answer
48 views

How to distinguish between output of numerous similar commands

Say I am issuing ls -la in a directory that has hundreds if not thousands of files, then changing to another directions and issuing ls -la. I then need to scroll up to see what files are in the most ...
0
votes
1answer
38 views

How to reduce the size of an mpeg file using the command line ?

I have a file, the output of the file command displays: jeff_western2.mp4: ISO Media, MPEG v4 system, version 1 I do not know how to lookup the resolution but it looks quiet high, the file itself ...
2
votes
6answers
163 views

Join lines of text with repeated beginning

I have a long text file (a tab-file for stardict-editor) which consists of lines in the following format: word1 some text word1 some other text word2 more text word3 even more and would like to ...
0
votes
2answers
56 views

Get all hardisk list (/dev/sd*)Using command line

I need to get all the hardisk connected to my PC like, /dev/sda /dev/sdb /dev/sdc later I have to use it in script and monitor using iostat I alrady found fdisk command, it seems to be hard ...
1
vote
5answers
3k views

How can I output the difference between 2 files?

My file consists of the the following; roughly: username:username:username:username:username The above line continues to about 600 characters. I use the awk command in order to use it as an ...
8
votes
1answer
4k views

Command-line mv exclusion list

Is there a way to mv,cp, or any file operation such that I could specify all the files I don't want affected? For example, say I have a folder with the files file1, file2, and file3, and I want to ...
1
vote
1answer
51 views

Is it possible to establish a Socket session (between Server and Client) using shell commands ?

From what I read (only the very outline, i do not know C Language) a Socket session is established between a server and a client by calling functions for both of them in a certain order. It starts ...
7
votes
1answer
324 views

In which situations are PS2, PS3, PS4 used as the prompt?

When I log on into the shell I see the prompt whose value is stored in PS1. I also encountereded another prompt (but do not know which one) when I used the here-document syntax: bc << HERE ...
3
votes
5answers
324 views

How to grep the n-th substring between given delimiters?

Let's say we have a string and its delimiter is ?: Leslie Cheung April 1 ? Elvis August 16 ? Leonard Nimoy February 27 I know how to grep the first substring between delimiters: echo $above_string ...
2
votes
2answers
40 views

Is it possible to change the PS1 periodically by a script in the background?

I just came across the PS1 variable (so I am far from being an expert). It is possible to change the prompt by simply changing this variables value, for instance: PS1="\h" hostname as Prompt PS1="\j" ...
1
vote
2answers
49 views

Can not evoke watch command with non-integer time option

I want to start the w command periodically, according to man watch the smallest possible time interval is 0.1. I tried: watch -n1 w (works) watch -n1.5 w (does not work) watch -n0.1 w ...
4
votes
3answers
176 views

Get last part of string after hyphen

Is there a simple command line to extract the last part of a string separated by hyphens? E.g., I want to extract 123 from foo-bar-123.