I currently working as a intern at a hosting firm. They asked me to write a bin/bash script to help automate a process to check the user's domain's and .pointers for them. And validate with a "whois" command if the domains/pointers are on our server's.
I'm new with bin/bash scripting but i was told i should check nested loops out. So to test my script out i made similar paths as they would look like on the server. /usr/local/directadmin/data/users/#USER#/domains.list and users/#USER#/domains/#DOMAIN NAME OF USER#.pointers
#part 1
for i in $(cat /home/MrC/Desktop/Users) #<the list of users i need to check)
do
if [ -f "/usr/local/directadmin/data/users/$i/domainlist.txt" ]
then
echo "/usr/local/directadmin/data/users/$i" >> /home/MrC/Desktop/output.tx$
cat "/usr/local/directadmin/data/users/$i/domainlist.txt" >> /home/carlos/Des$
fi
#part 2
for s in $(cat /home/mrC/Desktop/output.txt)
do
if [ -f "/usr/local/directadmin/data/users/$i/domains/$s.pointers" ]
then
echo "/usr/local/directadmin/data/users/$i" >> /home/MrC/Desktop/pointers.$
cat "usr/local/directadmin/data/users/$i/domains/$s.pointers" >> /home/MrC$
fi
done
done
So part 1 works this is the output.txt below
/usr/local/directadmin/data/users/testuser
lolla.nl
blaat2.nl
blaat3.nl
google2.nl
/usr/local/directadmin/data/users/testusers
blaat.nl
google.com
test.nl
pietje.nl
But i cant seem part two to work (no pointer file). my goal with part two of the script is to read the output (domainname) and put it #/$i/domains/$s.pointers.
I'm new on the forum i hope i asked my question in a proper fashion. if some one could give me hints/tips to which direction i should look that would be highly appreciated.
For
Do
if
then
for
do
COMMAND A
COMMAND B
COMMAND C
done
fi
done
while read -r i; do #stuff; done < /home/MrC/Desktop/Users (adjust IFS or specify the delimiter with the -d option to read).
– David C. Rankin
Related
Thank you for your concern.
I'm a noob trying to bulk-ip-lookup with [geoiplookup -f GeoLiteCity.dat] command.
I have more than 700 ips to lookup which saved on as c.txt (on the same folder)
How can I make a bash shell script? I've already made one and all I got was:
sudo: unable to execute ./ok.sh: No such file or directory
Here is my script
It would be all - ok to use another language.
To make it more clear;
[geoiplookup -f GeoLiteCity.dat IP1]
[geoiplookup -f GeoLiteCity.dat IP2]
...
[geoiplookup -f GeoLiteCity.dat IP700]
and save them as one text file. (Which would be 700 row)
I'm Korean and sorry for my poor English, but I couldn't find any in my language how to do this. I'll really appreciate it, or I have to look up 1 by 1 till Friday... (as internet speed is extremely slow in my company)
Please help me. I will pray for you at every sunday morning. Thank you.
found a very simple answer with a duckduckgo search for 'iterate through each line of file bash'
stackoverflow.com/questions/1521462/looping-through-the-content-of-a-file-in-bash
#!/usr/bin/bash
printf "\n\n"
while read ip; do
echo "LOOKING UP IP $ip"
geoiplookup $ip
printf "\n\n"
done < ipaddresses.txt
save it as iplookup.sh and run, without 'sudo':
bash iplookup.sh
tested and working. be sure to rename your file 'c.txt' to 'ipaddresses.txt' ! also the 'ipaddresses.txt' file must be in the same directory
I am using a bash script to execute a program. The program must take the following argument. (The program is gnuplot.)
gnuplot -e "filename='output_0.csv'" 'plot.p'
I need to be able to assemble the following string: "filename='output_0.csv'"
My plan is to assemble the string STRING=filename='output_0.csv' and then do the following: gnuplot -r "$STRING" 'plot.p'. Note I left the words STRING without stackoverflow syntax style highlighting to emphasise the string I want to produce.
I'm not particularly proficient at bash, and so I have no idea how to do this.
I think that strings can be concatenated by using STRING="$STRING"stuff to append to string? I think that may be required?
As an extra layer of complication the value 0 is actually an integer which should increment by 1 each time the program is run. (Done by a for loop.) If I have n=1 in my program, how can I replace the 0 in the string by the "string value" or text version of the integer n?
A safest way to append something to an existing string would be to include squiggly brackets and quotes:
STRING="something"
STRING="${STRING}else"
You can create the "dynamic" portion of your command line with something like this:
somevalue=0
STRING="filename='output_${somevalue}.csv'"
There are other tools like printf which can handle more complex formatting.
somevalue=1
fmt="filename='output_%s.csv'"
STRING="$(printf "$fmt" "$somevalue")"
Regarding your "extra layer of complication", I gather that this increment has to happen in such a way as to store the value somewhere outside the program, or you'd be able to use a for loop to handle things. You can use temporary files for this:
#!/usr/bin/env bash
# Specify our counter file
counter=/tmp/my_counter
# If it doesn't exist, "prime" it with zero
if [ ! -f "$counter" ]; then
echo "0" > $counter
fi
# And if it STILL doesn't exist, fail.
if [ ! -f "$counter" ]; then
echo "ERROR: can't create counter." >&2
fi
# Read the last value...
read value < "$counter"
# and set up our string, per your question.
STRING="$(printf "filename='output_%d.csv'" "${value}")"
# Last, run your command, and if it succeeds, update the stored counter.
gnuplot -e "$STRING" 'plot.p' && echo "$((value + 1))" > $counter
As always, there's more than one way to solve this problem. With luck, this will give you a head start on your reading of the bash man page and other StackOverflow questions which will help you learn what you need!
An answer was posted, which I thought I had accepted already, but for some reason it has been deleted, possibly because it didn't quite answer the question.
I posted another similar question, and the answer to that helped me also answer this question. You can find said question and answer here: bash: Execute a string as a command
I'm working on a bash script that will add users in a batch process. This code goes as follows:
#!/bin/bash
# A script that creates users.
echo "This is a script to create new users on this system."
echo "How many users do you want to add?"
read am
echo " "
for i in {0..$am..1}
do
echo "Enter a username below:"
read usern
sudo useradd $usern
sudo passwd $usern
echo " "
echo "User $am '$usern' added."
done
In this case, I wanted to make 4 users. I went through and entered the username "callum3" and set the password as "1234" for ease of login. Once I input everything (correctly, may I add) the terminal window displays the following.
User 4 'callum3' added.
This shows that my for loop isn't actually working, when I can see nothing wrong with it. I have tried using a while loop with no luck there either.
Am I making a rookie mistake here or is there something deeper going on?
Although I suspected it, for a better understanding on what could be wrong with your script I pasted it in shellcheck.net. That the problem is in the line:
for i in {0..$am..1}
Bash doesn't support variables in brace range expansions. That is, you cannot use a variable in an expression like {..}.
Instead, use seq. With seq $var you get a sequence from 1 (default) to $var:
for i in $(seq "$am")
I feel like I'm missing something in that nobody has suggested an arithmetic for loop:
for ((i=0; i<am; i++)); do
…
done
This has the particular benefit in bash of being both readable and not requiring a subshell.
You can use:
for i in `seq 0 $((am-1))`
do
...
done
Sequence will start from 0 and end at $am-1
I have an automated process that has a number of lines like the following pattern:
sudo cat /some/path/to/a/file >> /some/other/file
I'd like to transform that into a one liner that will only append to /some/other/file if /some/path/to/a/file has not already been added.
Edit
It's clear I need some examples here.
example 1: Updating a .bashrc script for a specific login
example 2: Creating a .screenrc for different logins
example 3: Appending to the end of a /etc/ config file
Some other caveats. The text is going to be added in a block (>>). Consequently, it should be relatively straight forward to see if the entire code block is added or not near the end of a file. I am trying to come up with a simple method for determining whether or not the file has already been appended to the original.
Thanks!
Example python script...
def check_for_appended(new_file, original_file):
""" Checks original_file to see if it has the contents of new_file """
new_lines = reversed(new_file.split("\n"))
original_lines = reversed(original_file.split("\n"))
appended = None
for new_line, orig_line in zip(new_lines, original_lines):
if new_line != orig_line:
appended = False
break
else:
appended = True
return appended
Maybe this will get you started - this GNU awk script:
gawk -v RS='^$' 'NR==FNR{f1=$0;next} {print (index($0,f1) ? "present" : "absent")}' file1 file2
will tell you if the contents of "file1" are present in "file2". It cannot tell you why, e.g. because you previously concatenated file1 onto the end of file2.
Is that all you need? If not update your question to clarify/explain.
Here's a technique to see if a file contains another file
contains_file_in_file() {
local small=$1
local big=$2
awk -v RS="" '{small=$0; getline; exit !index($0, small)}' "$small" "$big"
}
if ! contains_file_in_file /some/path/to/a/file /some/other/file; then
sudo cat /some/path/to/a/file >> /some/other/file
fi
EDIT: Op just told me in the comments that the files he wants to concatenate are bash scripts -- this brings us back to the good ole C preprocessor include guard tactics:
prepend every file with
if [ -z "$__<filename>__" ]; then __<filename>__=1; else
(of course replacing <filename> with the name of the file) and at the end
fi
this way, you surround the script in each file with a test for something that's only true once.
Does this work for you?
sudo (set -o noclobber; date > /tmp/testfile)
noclobber prevents overwriting an existing file.
I think it doesn't, since you wrote you want to append something but this technique might help.
When the appending all occurs in one script, then use a flag:
if [ -z "${appended_the_file}" ]; then
cat /some/path/to/a/file >> /some/other/file
appended_the_file="Yes I have done it except for permission/right issues"
fi
I would continue into writing a function appendOnce { .. }, with the content above. If you really want an ugly oneliner (ugly: pain for the eye and colleague):
test -z "${ugly}" && cat /some/path/to/a/file >> /some/other/file && ugly="dirt"
Combining this with sudo:
test -z "${ugly}" && sudo "cat /some/path/to/a/file >> /some/other/file" && ugly="dirt"
It appears that what you want is a collection of script segments which can be run as a unit. Your approach -- making them into a single file -- is hard to maintain and subject to a variety of race conditions, making its implementation tricky.
A far simpler approach, similar to that used by most modern Linux distributions, is to create a directory of scripts, say ~/.bashrc.d and keep each chunk as an individual file in that directory.
The driver (which replaces the concatenation of all those files) just runs the scripts in the directory one at a time:
if [[ -d ~/.bashrc.d ]]; then
for f in ~/.bashrc.d/*; do
if [[ -f "$f" ]]; then
source "$f"
fi
done
fi
To add a file from a skeleton directory, just make a new symlink.
add_fragment() {
if [[ -f "$FRAGMENT_SKELETON/$1" ]]; then
# The following will silently fail if the symlink already
# exists. If you wanted to report that, you could add || echo...
ln -s "$FRAGMENT_SKELETON/$1" "~/.bashrc.d/$1" 2>>/dev/null
else
echo "Not a valid fragment name: '$1'"
exit 1
fi
}
Of course, it is possible to effectively index the files by contents rather than by name. But in most cases, indexing by name will work better, because it is robust against editing the script fragment. If you used content checks (md5sum, for example), you would run the risk of having an old and a new version of the same fragment, both active, and without an obvious way to remove the old one.
But it should be straight-forward to adapt the above structure to whatever requirements and constraints you might have.
For example, if symlinks are not possible (because the skeleton and the instance do not share a filesystem, for example), then you can copy the files instead. You might want to avoid the copy if the file is already present and has the same content, but that's just for efficiency and it might not be very important if the script fragments are small. Alternatively, you could use rsync to keep the skeleton and the instance(s) in sync with each other; that would be a very reliable and low-maintenance solution.
I'm new programming in shell and I need some help with this code...
Buildname= test
echo $Buildname > lbuild
cbuild < lbuild
echo $cbuild
So echo $cbuild must display the first line in the text file created.
can someone help me with that?
Use read
read -r cbuild < filename
I think you either want double quotes around the test in Buildname = test or there is more to the script. :-)
I took the liberty of assuming I know what you need, here's my swag at it:
#! /bin/bash
Buildname="test"
echo $Buildname > lbuild
cbuild=$(cat lbuild)
echo $cbuild