A script is a sequence of commands or instructions that are executed by an interpreter program rather than compiled into a standalone executable program.
0
votes
2answers
16 views
Using grep to find first two numbers of IP addresses?
I'm trying to figure out how to use grep to pull out only the first two numbers of an IP address in a list. I've got a routine that is isolating the log entires (from Exim) that I need, now I just ...
0
votes
1answer
31 views
Make a bin script acts as an argument [on hold]
I'm using PRIME in a two GPU system.
To start a game, I'd use something like:
DRI_PRIME=1 game
What I want is to make a bin executable that will act as an argument (ie. DRI_PRIME=1) before another ...
1
vote
2answers
38 views
How to notice log file changes with Linux standard tools? [duplicate]
I need something that does not need to be installed. It's on an embedded system with very little space on the HD. I can't instal anything. I need to do it with something that is already included.
I ...
3
votes
3answers
93 views
Shell Script to move folders containing a specific word
I'm searching for an simple shell script to mv all folders in /var/www/uploads/ that containing Math or Physics in the name to /mnt/Backup/.
I've never done something like that before, due to the ...
0
votes
1answer
22 views
Prompting when redirecting content of script to remote machine
I have simple script:
#!/bin/bash
while getopts ":u:" opt; do
case $opt in
u)
USER="${OPTARG}"
;;
\?)
echo "Unknown flag has been used: -$OPTARG" >&2
exit 1
...
-1
votes
1answer
31 views
How does fakeroot script work? [closed]
Could somebody please explain how exactly the fakeroot script works?
[Edit]
The fakeroot script works together with libfakeroot-sysv.so.
A detailed step-by-step explanation is needed.
3
votes
2answers
80 views
shell script problem with using the operators
I am comparing two strings using the levenshtein distance algorithm. I got the PHP implementation of the algorithm from here. I am calling this php implementation from my shell script as below.
...
1
vote
1answer
34 views
Differences between %pre and %post in Kickstart on CentOS?
I have been setting up machines with Kickstart on CentOS and I am unsure about the differences between the %pre and %post sections of the kickstart .cfg file.
The CentOS Documentation for the ...
0
votes
0answers
7 views
mysql optimized query execution [migrated]
As part of an ongoing research work, I am checking if an URL exists or not using the cURL command. I have been executing a shell script for couple of days and it is doing some updates for each URL in ...
6
votes
1answer
146 views
Parallel execution of bash script
I have a table URL_Experiment in my database (mySQL database). I have 2 million URL links in this table.
For each URL, I am checking if some particular text is present in the URL and updating the ...
0
votes
1answer
31 views
Need to grep for specific lines from ongoing log and save it in some file
So, let me start with the overall outcome that i want to achieve.
There is just one log, which will have info on certain devices, that i am upgrading.
I use "tailf log" to monitor the log.
Now, ...
1
vote
1answer
25 views
Pressing tab after sourcing script file prints script related output
I have a script file in a directory. Its contents are as follows :
#!/bin/bash ...
1
vote
1answer
22 views
print all values of a file after removing some characters using grep
I have a file in which the values are stored as below.
Assistant Professor at SASTRA University
St John's memorial college
Paul George Univeristy
Department Chair at University of Texas
I am ...
2
votes
3answers
52 views
Extracting characters after a particular text
I am extracting a page from website using cURL command.
curl "www.google.com" -s | w3m -dump -T text/html > foo.txt
The w3m command outputs the HTML page in a much more simpler format so that ...
2
votes
1answer
51 views
shell script construct array for file elements
I have a file named input_file which contains some lines. I need to remove certain characters in the line and store them in an array. So to remove the characters, I use the sed command and storing in ...
1
vote
2answers
32 views
Make Trickle get the correct $PATH
Trickle is a bandwidth limiting program. I have the following script for trickle.
#!/bin/bash
echo $PATH
trickle -s -t 3 -u 200 -d 200 "$@"
I have a script in ~/bin/ that want to run the script ...
1
vote
1answer
48 views
curl and grep commands output into a new variable
I am extracting information from a website. I designed the code in VBA and found that it is taking too long to execute. So, I have decided to rewrite the code in Unix script. I am extracting a page ...
0
votes
1answer
44 views
What's the safest way to pipe an email to a script via procmail?
I have a simple procmailrc recipe that hands mail off to a script:
LOGFILE=/home/foouser/procmail-log
VERBOSE=yes
MAILDIR=/var/spool/mail/foouser
DEFAULT=/var/spool/mail/foouser
SHELL=/bin/sh
...
2
votes
1answer
36 views
Why does AWK not like dots in one of two substitutions?
I'm trying to use AWK in a bash script to look for a placeholder string in a template file and replace it with the contents of a variable that (can) contain various special characters.
Example:
...
2
votes
2answers
83 views
Use awk to split line into array and use that array's values in calling shell
First of all, my apologies for the somewhat clumsily worded title. If you can think of a better one, please feel free to edit. [EDIT: done]
What I am trying to do is use awk inside a bash script and ...
-3
votes
1answer
27 views
why does the dollar sign cause this command to be executed?
test_script.sh:
#!/bin/sh
D1="$(dirname $0)"
echo $D1
D0="(dirname $0)"
echo $D0
What I type on the command line:
$ ./test_script.sh
Output:
.
(dirname ./test_script.sh)
What significance ...
1
vote
2answers
53 views
How to check if string starts with value containing #, tab, and maybe space?
In my bash script, I want to check whether a string starts with # modified: or # new file:. In both instances, the character after # is a tab. In the latter instance, the character between ...
4
votes
5answers
1k views
Using $? in an if statement
function foo {
(cd $FOOBAR;
<some command>
if [$? -ne 0]
then
echo "Nope!"
else
echo "OK!"
fi
)
}
I am trying to write a function like the one above and place ...
0
votes
1answer
46 views
Can I use an if statement to detect if bash and dash are being run interactively? [duplicate]
After looking around for a while I've found several good pages describing how to check and see if a bash script is running interactively and there seem to be several methods, but one of them that I ...
5
votes
1answer
51 views
Is there any guarantee that /usr/bin/env will exist?
Often I will see scripts begin with a shebang line that uses #!/usr/bin/env interpreter_name for whatever interpreter, with the rationale that different systems might have the interpreter that they ...
2
votes
2answers
47 views
How to split files with common prefix in bash
I have a directory with many files with common prefix, like gsc*_other.foo, where * is a character that goes from 0 to 9 or a/b (where a stands for 10 and b for 11).
My goal is to create text files ...
2
votes
3answers
24 views
setting up script in a linux machine for scientific computation [closed]
I'd like to setup machine for test some computation in my old laptop, before replicate the tests on the server. The computation will be image-processing and machine learning, run some program, load ...
0
votes
1answer
57 views
How to execute Netscaler commands through a remote machine via SSH connection
I have been trying to execute some NetScaler commands like "bind" & "unbind" through a Linux Box via an SSH Connection.
Now the Problem is, Manually we are able to enter & execute commands on ...
2
votes
2answers
71 views
Using Sed with Regex
I would need to edit the values in a file delimited by colons (:)
I would like to replace the contents of the file by using regular expression.
After a grep to confirm that the item exist in the file ...
1
vote
2answers
41 views
Is this an array?
I'm currently looking at an existing script that have something like this:
variable='val1 val2 val3 val4'
Is this another way of setting an array? If not, what is it?
5
votes
3answers
159 views
Using notify-send with cron
I am using Arch Linux with KDE/Awesome WM. I am trying to get notify-send to work with cron. I have tried setting DISPLAY/XAUTHORITY variables, and running notify-send with "sudo -u", all without ...
3
votes
2answers
111 views
Human readable dmesg time stamps on OpenWRT
The output of dmesg shows the number of second+milliseconds since the system start.
[ 10.470000] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[ 14.610000] device eth0 entered ...
1
vote
4answers
55 views
Bash Script to Sort Files into Alphabetical Folders on ReadyNAS Duo v1
I have an old ReadyNAS Duo v1 (Sparc) running an unknown flavour of Linux.
I have a folder structure with 1,000+ files I want to move into a folder structure based on the first letter of the file ...
5
votes
4answers
133 views
Prefixing and appending blocks of text to a list of files
I'm trying to prefix and append blocks of text to a list of files. Here is where I am so far. The sticking point is the sed -i "1i \$prefix" "$file" && line. sed won't substitute the value of ...
1
vote
1answer
39 views
Bash: show prompts if arguments weren't provided
What is the best way of supporting in the script prompts and arguments at the same time? I want to show prompts if arguments weren't provided.
Is there something better/shorter than this? ⇩
...
4
votes
1answer
81 views
Bash is automatically reloading (injecting) updates into a running script upon saving it: Why? Any practical use?
I was writing a bash script, and happened to updated the code (saved the script file to disk) while the script was waiting for some input in a while loop. After I returned to the terminal and ...
1
vote
2answers
82 views
Bash script to adjust brightness when battery unplugged
I am trying to set up my system and to get some practice with scripting and the like. I am running Linux Mint 16 on a Samsung RC520 laptop (Linux 3.11.0-12-generic x86_64). I want to implement a ...
0
votes
0answers
38 views
Video tools for creating presentation
I have captured video (with audio) from presentation, slides (just images), and array of times (when slides was listed).
Goal is to create presentation video: big slide with small video frame at the ...
3
votes
0answers
34 views
GRUB 2 scripting: convert device name in GRUB notation into a Linux device name
I'm trying to use partition labels (or UUIDs, that does not matter) to select root partition without use of an initrd/initramfs.
With initramfs, this is fairly easy: root=LABEL=... or ...
1
vote
1answer
56 views
Number of cores on FreeBSD
What would the equivalent of Debian's nproc be in FreeBSD? I'm trying to include this in a bash script variable so if it could just print out the number of cores that would be fantastic.
0
votes
3answers
64 views
How to compact a chmod UNIX command
Is there anyway to compact the follow UNIX command:
chmod 755 scriptA.ksh | chmod 755 scriptB.ksh | chmod 755 scriptC.ksh | chmod 755 scriptD.ksh
The above command makes every KornShell (ksh) ...
8
votes
3answers
172 views
Send email written in markdown using mutt
Sometimes I need to send a fragment of code on google-group inline. Text does not help here; I can type it in markdown, convert it to html (using pandoc etc.), attach to mutt as text/html and send it.
...
2
votes
0answers
53 views
Automating startup tasks
I have a "morning ritual" that occurs on every boot of my machine: starting up a few browser tabs, starting up skype, starting up terminator and subdividing some screens, etc.
Is there any tool that ...
1
vote
1answer
62 views
Linux - Sending a command to a screen through a shell script? [duplicate]
I'm trying to figure out how to make a script that will be able to send commands to a screen that will execute within whatever the screen is doing. Is this possible, and if so, how is it done? I've ...
1
vote
1answer
48 views
Linux - How to open a console and display command results on startup?
I have a Linux server with a screen always displaying the end of a very usefull file.
How could I automatically enter a shell and display the end of this file when the server starts?
I'd like to do ...
1
vote
1answer
70 views
How can you run a script triggered by a joystick input?
I'm using a Raspberry Pi running Raspbian to power my arcade cabinet. I want to shut the Pi down using the sudo poweroff command without using the keyboard. I'm thinking the best way would be to ...
16
votes
5answers
611 views
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 ...
2
votes
1answer
135 views
permission denied on scripts in ~/bin
I set some additional locations to the PATH environment variable in my ~/.bashrc so that these are included/sourced in logins and non-interactive scripts that are scheduled with cron.
I've noticed ...
0
votes
1answer
24 views
Copying specific text from one file into a schema
I have two files. One being a schema, and the other a list of data. The schema looks like:
line_name:
shot_edit:
channel edit:
cable_edit
and repeats regularly for the number of lines that I ...
2
votes
2answers
138 views
How can I print only certain commands from a bash script as they are run?
I have a bash script with various if statements based on command line arguments I pass in when calling it. Having some kind of output as to what commands are being run is helpful to confirm the flow ...
