The shell is unix's command-line interface. You can type commands in a shell interactively, or write scripts to automate tasks.
0
votes
1answer
13 views
TAB autocomplete on sudo sh
When I say sudo sh, TAB stops working as autocomplete signal on my Debian.
How can I enable TAB key autocomplete after I say sudo sh ?
0
votes
0answers
33 views
unexpected bash behaviour after console login (openSUSE)
I'm trying to install a Linux OS on the computer I use as a home server, because I liked "Raspbian" so much on my Raspberry Pi. I created a custom linux using openSUSE Studio, that's just text based ...
4
votes
2answers
29 views
Passing globbing expressions to functions/scripts
The following script is supposed to concatenate multiple csv files in a path specified in the first argument into a single csv file specified in the second argument
#!/bin/zsh
set -x
set -v
...
0
votes
0answers
13 views
Getting “zsh: command not found: time” when running `time` in subshell
I installed ZSH (and Oh-My-ZSH) on a Ubuntu 12.10 64 bit machine a few days ago. I just tried to do:
time (time ls)
and got this error:
zsh: command not found: time
( time ls; ) 0.00s user 0.00s ...
2
votes
2answers
45 views
Linux listing files between two date without touch command
I need a command which will list the files between given date and time (YYYYMMDDHHMMSS - format) in to a text file.
I don want to use touch command as its creating permission issue.
I am new to this ...
3
votes
1answer
41 views
Can't indent heredoc to match nesting's indent
If there's a "First World Problems" for scripting, this would be it. Mainly asking because I feel like I should know how to get around it if I need to.
I have the following code in a script I'm ...
1
vote
3answers
62 views
How to know which is the default script shell in Centos?
I'm using Centos 6 and after reading about different shells and dash implementasion as sh replacement in Debian, Ubuntu and Fedora, made up my mind to replace sh with dash as the script shell in ...
3
votes
3answers
107 views
Concatenating thousands of files: > vs >>
I found two seemingly contradictory answers on StackOverflow to the following questions:
Concatenating Thousands of Text Files Across Hundreds of Directories (while keeping some structure)
How do I ...
15
votes
2answers
441 views
Command line: <<< instead of <<
Why is the command md5sum <<< 'ddd'
(output: d6d88f2e50080b9602da53dac1102762 -)
right, and md5sum << 'ddd' not?
What does <<< mean?
5
votes
4answers
223 views
How to make `cd dir/filename` take me to dir/?
I would find it very convenient to be able to use cd with a file argument.
cd myDirectory/anyname.anyExtension
would be equivalent to
cd myDirectory/
What would be the best alias or function to ...
1
vote
2answers
66 views
What does the tilde (~) mean at the end of a filename? [duplicate]
What is the file with the ~ at the end of the filename for?
$ ls # aliased to add flags
-rwxrwxr-x 1 durrantm 2741 May 16 09:28 strip_out_rspec_prep_cmds.sh~*
drwxrwxr-x 13 durrantm 4096 May 16 ...
1
vote
1answer
23 views
How to open all the files in a directory, using terminal, in emacs?
I've 4 java files in a directory, which I want to work with in emacs. How do I open them all together? Thanks
0
votes
1answer
32 views
List partitions in grub2 shell?
I've been doing some spring cleaning of my hard drive. This cleaning caused my grub configuration to get messed up ( no surprise there ). So when I boot I wind up in the grub2 shell. ( The shell with ...
3
votes
3answers
34 views
Print process ID (PID) of a Matlab instance
To run my Matlab scripts, I've created a shell script to which I give two parameters - the path to the matlab file ($1) and to the log file ($2):
nohup time matlab -some_parameters -r "run $1;exit" ...
0
votes
2answers
45 views
At init, run my own script instead of the shell
This is purely theoretical but suppose I would like to deploy a linux distribution on many servers. The only solution I can think of would be to create an initramfs with a custom script to perform ...
0
votes
1answer
27 views
Weird behavior when sourcing .zshrc
I'm using zsh 5.0.2 (x86_64-apple-darwin12.3.0) on the latest MacOSX. If it makes any difference, I have also enabled oh-my-zsh.
The shell seems to be missing the .zshrc file when I want to source ...
1
vote
3answers
73 views
sed - how to replace a single quote?
This works fine:
sed -i 's# @driver.find_element(:xpath, "//a\[contains(@href,##' temp_spec.rb
against a source of
@driver.find_element(:xpath, "//a[contains(@href,'change_district')]").click
...
4
votes
4answers
107 views
sed how to substitute when string has “http://” in it?
I have a file xx that has the following contents:
@base_url = "http://dmstaffing-stage.herokuapp.com/"
I want to use sed to eliminate this line (replace with nothing). I have used this sed ...
3
votes
0answers
56 views
Fork vs. thread system time [closed]
I got the following logs:
Program 1:
Taken from a program executed 64 fork calls:
real 0m0.023s
user 0m0.068s
sys 0m0.008s
Program 2:
Taken from a program executed 64 thread calls:
real 0m0.613s
...
1
vote
1answer
40 views
gunzip multiple compressed files to another directory without deleting the .gz files
I have multiple .gz file in a folder and I want to unzip it in other folder through gunzip without deleting parent file. Please help.
0
votes
2answers
71 views
Is there a general command to see what shell is running? [duplicate]
On some the shell can be read on in the command prompt, other can be seen when help is ran. But this are not covered by all the shells.
Is there a general command to see what shell is running?
3
votes
1answer
30 views
Ignore files for zsh's completion for SVN
I managed to configure zsh such that it does not suggest LaTeX temporary files when I use autocompletion for emacs by adding this line to my ~/.zshrc:
zstyle ':completion:*:*:emacs:*:*files' ...
3
votes
6answers
172 views
How do I specify arguments to return all dot files, but not . and ..?
Normally dot files are not included for wildcard expansion:
% echo *
Applications Desktop Documents Downloads Library Movies Music Pictures Public bin
If I explicitly ask for dot files, I get them:
...
9
votes
4answers
196 views
+100
Why do I have to re-set env vars in tmux when I re-attach?
I mainly work on a mac and ssh/tmux attach to a Linux machine to do my work. I have ssh-agent running on the Linux machine. I have
set -g update-environment "SSH_AUTH_SOCK SSH_ASKPASS WINDOWID ...
3
votes
1answer
73 views
How can I keep color codes with grep input?
It I grep something twice:
... | grep foo | grep bar
It seems foo is not highlighted.
Infact, it seems grep removes colorcodes from its input; Any way to prevent this?
1
vote
1answer
24 views
Different “history” command output after reconnecting via SSH
Why do I get different results for the "history" command for the same user after I reconnect a disconnected SSH session?
I connect to a server using putty (SSH), say as root
My network gets ...
2
votes
3answers
50 views
Forcibly create directory hard link(s)?
I understand the reasoning why nearly every unix version doesn't allow hard-linking of directories (in fact HFS+ on OS X is the only one I know, but even that isn't made easy to do yourself). However, ...
9
votes
3answers
338 views
Why does “$(( ~33 ))” produce -34?
$ echo $(( 255 ))
255
$ echo $(( 33 ))
33
$ echo $(( ~33 ))
-34
$ echo $(( ~255 ))
-256
$
and my kernel is:
$ uname -a
Linux HOSTNAME 3.2.0-40-generic-pae #64-Ubuntu SMP Mon Mar 25 21:44:41 UTC ...
2
votes
1answer
33 views
redirection to file issues with nohup and pipe
for the following script
ssh -t esolve@hostname 'sudo nohup bash -c "ls > log 2>&1 &"'
I always got error information:
nohup: ignoring input and appending output to ...
2
votes
2answers
42 views
how to initialize `/etc/group`?
After editing /etc/group, How this update starts functioning without restarting the system in Unix?
Is there any command we need to run?
21
votes
7answers
2k views
why does ls -d also list files, and where is it documented?
when specifying ls --directory a* it should list only directories starting with a*
BUT it lists files AND directories starting with a
Questions:
where might I find some documentation on this, ...
3
votes
2answers
55 views
Wait for a X window to appear/disappear (in a sane way)
Inside a shell script, I need to wait for a window that has a string on its title to appear, do some action, and then wait for it to disappear, and do some other action.
Until yesterday, I had this ...
2
votes
3answers
43 views
Log in with specific shell at terminal login
If I log in to a system over ssh, I can use the default shell with a simple ssh user@host, or specify something like ssh user@host 'bash --norc --noprofile' or ssh user@host ksh.
Is it possible to ...
2
votes
1answer
60 views
File no longer available when trying to edit in vim via <()
When working with mercurial, I frequently do things like
vim <(hg cat -r 42 somefile)
However, if I try this with a file larger than several hundred lines, I get a Read Error in vim, and only ...
2
votes
1answer
72 views
What does “${x%% *}” mean in sh? [duplicate]
I just saw "$${x%% *}" in a makefile, which means "${x%% *}" in sh.
Why it is written in this way ?
how can a makefile detect whether a command is available in the local machine?
determine_sum = \
...
3
votes
3answers
92 views
How to move all files with a certain file extension from subdirectories to a single directory
I have a directory that contains many subdirectories. The subdirectories contain lots of types of files with different file extensions. I want to move (not copy) all the files of one type into a new ...
1
vote
2answers
83 views
shell script to do some text manipulation of text file data structure and slight content changes
Apologies in advance for the wall of text, not sure how else to represent the existing data structure.
I have been handed about a years worth of logs collected every hour from a server.
Sadly, ...
1
vote
2answers
56 views
How to make sure the shell builtin echo is invoked so that its not visible in process list?
Is this going to be visible in the process listing if the below line is executed from a command line or a shell script
bash -c "echo $password"
or
i just need to do echo $password from within ...
2
votes
1answer
34 views
process continous output of synclient
I am using synclient to track the position of finger on the touchpad.
I use the following command.
synclient -m 100 | awk '{print $2,$3}'
This command gives the 'x' and 'y' co-ordinate on the ...
6
votes
2answers
118 views
Decode Flags for Kill Command
I am new to Shell Scripting.
I saw this Command on a Book for Linux shell Scripting
$ kill -HUP 1234 >killout.txt 2>killerr.txt
I know what the command does, but i am not able to understand ...
1
vote
1answer
56 views
Standard I/O File Descriptors
I am new to Shell SCripting
I code this
$ ls -l 1> stdout.txt
and I get the output as desired,
1> stdout.txt
redirects the output from standard output to the file stdout.txt.
I don't ...
2
votes
0answers
50 views
zsh: Echoing every statement?
I have an odd problem with zsh when I switch between shells in a particular way:
Option 1 (works well):
I start a zsh shell. I switch to tcsh with /bin/tcsh, and I switch back to zsh with /bin/zsh
...
2
votes
2answers
60 views
Including sub-parameters in help options to execute wisely without getopt or getopts?
I am writing a script which can choose a file and print specific content. For example,
san#./script.sh
Expected Usage : ./script.sh --file1 --dns
(Here it checks for file1, search for dns name and ...
1
vote
1answer
59 views
How to open process substituted file from php?
Here's what I tried to do myself:
$ type 1.sh
#!/bin/bash -eu
php -r 'var_dump(file_get_contents($_SERVER["argv"][1]));' -- <(echo 1)
$ ./1.sh
PHP Warning: file_get_contents(/dev/fd/63): failed ...
0
votes
1answer
49 views
Can I redirect output to a log file and background a process at the same time?
Can I redirect output to a log file and background a process at the same time?
In other words, can I do something like this?
nohup java -jar myProgram.jar 2>$1 > output.log &
Or, is that ...
4
votes
1answer
41 views
Suspend and edit previous single line commands
Say I want to modify the latter of some concatenated command line options, is it possible without killing the first command?
Specifically I have compile and run scripts executed thusly:
> compile ...
1
vote
1answer
74 views
what's wrong with embedding php scripts inside bash ones?
I was trying to use php inside bash script, but I came across several problems. My first try failed with error about bash not being able to find end of here-document. The minimal version that still ...
4
votes
1answer
47 views
Understanding when background process gets terminated
I have a script which starts a number of background processes and if works fine when called from the cmdline.
However the same script is also called during my xsession startup and additionally on ...
16
votes
5answers
893 views
In what situations would a user not let the shell record his command into history?
If I add export HISTCONTROL=ignorespace in .bashrc, bash won't record any commands which have whitespace before them into history. But I do not understand under what situations it will be useful. ...
12
votes
4answers
497 views
difference between function foo() {} and foo() {}
I can define bash functions using or omitting the function keyword. Is there any difference?
#!/bin/bash
function foo() {
echo "foo"
}
bar() {
echo "bar"
}
foo
bar
Both calls to functions ...
