My current snippet of code looks like this ...
#Location of network config files
nfds="/etc/sysconfig/network-scripts/"
#Standard prefer of network config files
fil="ifcfg-"
#Array variable that feeds "$nic"
cards= array loop built from "nic=$(ls /sys/class/net | grep en)"
#Set color for Divice labile
div="\033[38;5;39m"
#Set Fix format and colour info
fix="\033[38;5;118m"
#Set color for OK
ok="\033[38;5;28m"
#Clear All font and color info
ctf="\033[0m"
function currentCardDefRoute(){
defr=$(grep DEFROUTE $nfds$fil$cards | cut -d = -f 2)
if [[ $defr = "yes" ]] || [[ $defr = "no" ]]; then
echo -e " "$div$cards$ctf"'s current default route is\t"$div$defr$ctf"\t\t\t\t ["$ok"OK"$ctf"]"
$st
else
echo -e " "$div$cards$ctf"'s current default route is \t"$fix"Missing"$ctf"\t\t\t ["$fix"PLEASE FIX"$ctf"]"
$st
fi
}
I indent 1 space on all echo lines for readability and consistent formatting. Keeping output readable and easy to understand.
Im looking to us the "columns" option and make the output more dynamic and have the format consistent no matter the screen size or var result. I would love to also get rid of all the "\t"s in my code. I have tried printf to no success.
I googled a lot of different ways and not seen the specific answer Im looking for or a variation I can draw an answer from.
Thank you for your help.
btw. This is the first code I have ever written so go easy guys :)
You may want to try using the column utility. It's sole purpose is for formatting output into columns. That may be easier than trying to do the same thing with echo or printf.
If you have to use printf, you'll want to use a format specifier like "%25.25s". The first number is the "minimum field width", which (in this case) causes the output to be at least 25 characters wide. If the output is shorter, it's padded with whitespace. The second number indicates the maximum number of characters to print. When these two numbers are the same, it effectively says to print the string in a field that's exactly 25 characters wide. You can use this to force varying-length strings to take up the same amount of space on the screen.
Related
I want to have a standard BASH PS1 prompt that will automatically have a colour set based upon the hostname of the server.
This would meant that whenever logging into a server, it would instantly be clear and familiar that you are on that server as the prompt colour would be different to other servers
A given hostname must always give the same colour
I have found similar ideas with hex codes, but this is specifically for use with BASH colours
The idea would then be that there can be a standard bash prompt code snippet that can be included everywhere and will always give different colours for different servers without any further code changes
In a nutshell, the question is what bash function could you write that will take 2 arguments - a string and a hash. It should echo out the string in a colour that is determined by the hash, and the colour should always be the same for any given hash
EDIT - TO CLARIFY
the answers so far assume that host names are known in advance
I am looking for something that will assign the same random colour deterministically based on whatever host name is for that server
I am definitely not looking for something that requires any kind of code change when installing the PS1 on a new server
This post is along the lines but doesn't seem to have a simple PS1 snippet that I can use https://aweirdimagination.net/2015/02/28/better-hash-based-colors/
I am looking for something that will assign the same random colour deterministically based on whatever host name is for that server
Take a hashing algorithm and compute the hash of the hostname - as to convert a string to numbers. Then use this pseudorandom-number to generate a color.
gen_prompt_function() {
local number
number=$(
# get "random" string that depends on hostname
md5sum <<<"$HOSTNAME" |
# meh - take first byte and convert it to decimal
cut -c-2 | xargs -i printf "%d\n" "0x{}" |
# convert 0-255 range into 30-37 range
awk '{print int($0/255.0*(37-30)+30)}'
)
printf '\[\e[%d;1m\]%s\[\e[m\]' "$number" "$HOSTNAME"
}
PS1="$(gen_prompt_function)"'$ '
Read ANSI escpe sequences, tput and about color handling in terminfo and bash manual controlling prompt. Remember to add \[ \] around color codes.
PS. In my bash adventures solely for hostname prompt coloring I have written a color handling script that generates a rainbow from 3 RGB colors taken from first 18 characters extracted from hash of a string, like in screeshot below. That script is used in my PS1 configuration.
declare -A color=([hosty]=33 [hostr]=31 [hostb]=34 [hostm]=35)
function color () {
host=$1
printf $'\e[%d;1m%s\e[m' "${color[$host]}" "$host"
}
PS1='$(color $HOSTNAME)$ '
Determine what the host name is, then define PS1.
case $HOSTNAME in
foo.com) color='...' ;;
bar.org) color='...' ;;
esac
PS1="..." # using $color as necessary
I am writing a shell script, in which I get the location of java via which java. As response I get (for example)
/usr/pi/java7_32/jre/bin/java.
I need the path to be cut so it ends with /jre/, more specificly
/usr/pi/java7_32/jre/
as the programm this information is provided to can not handle the longe path to work.
I have used cut with the / as delimiter and as I thought that the directory of the Java installation is always the same, therfore a
cut -d'/' -f1-5
worked just fine to get this result:
/usr/pi/java7_32/jre/
But as the java could be installed somewhere else aswell, for example at
/usr/java8_64/jre/
the statement would not work correctly.
I need tried sed, awk, cut and different combinations of them but found no answer I liked.
As the title says I would count the number of appereance of the car / until the substing jre/ is found under the premisse that the shell counts from the left to the right.
The incremented number would be the the field I want to see by cutting with the delimiter.
path=$(which java) # example: /usr/pi/java7_32/jre/bin/java
i=0
#while loop with a statment which would go through path
while substring != jre/ {
if (char = '/')
i++
}
#cut the path
path=$path | cut -d'/' -f 1-i
#/usr/pi/java7_32/jre result
Problem is the eventual difference in the path before and after
/java7_64/jre/, like */java*/jre/
I am open for any ideas and solutions, thanks a lot!
Greets
Jan
You can use the shell's built-in parameter operations to get what you need. (This will save the need to create other processes to extract the information you need).
jpath="$(which java)"
# jpath now /usr/pi/java7_32/jre/bin/java
echo ${jpath%jre*}jre
produces
/usr/pi/java7_32/jre
The same works for
jpath=/usr/java8_64/jre/
The % indicates remove from the right side of the string the matching shell reg-ex pattern. Then we just put back jre to have your required path.
You can overwrite the value from which java
jpath=${jpath%jre*}jre
IHTH
You can get the results with grep:
path=$(echo $path | grep -o ".*/jre/")
i have config file like this for example:
# Blah blah, this is sample config file blah blah
# Something more blah blah
value1=YES
value2=something
#value3=boom
# Blah blah
valueN=4145
And i want to make script to read and edit config files like this. I thinking about make a menu with groups of config options, then after write an option console output will be like this:
Group of funny options (pick option to change value):
1. value1=YES
2. value2=something
3. [disabled]value3=boom
After picking 1 for exaple i can change value1 from YES to NO or disable and activate other (hash unhash) plus adding new variables to the end of file. Then in the end save all changes in this config file. Any tips what i need to use? Actually trying with read line + awk to skip # lines (with space), but still i have problem to get all this variables and making changes in config file. I will be grateful for your help.
Edit.
while read line
do
echo $line | awk '$1' != "#" && / / { print $1 $3 }'
done < config.conf
Thinking about this for now to read informations what i want. Plus i'm gonna use something like this to change values:
sed -c -i "s/("one" *= *).*/\1$two/" config.conf
I have completly no idea how i can get this variables to my script and use it like i write before. Actually i search for any tips, not someone who write this script for me. I'm beginner at linux scripting :V
I would recommend to abstain from such an, seemingly generic configuration program, because the comments might contain important informations about the current value and will be outdated, if the values change, while the comments don't.
Second problem is, that I would expect, if activating an entry is possible, deactivating it should be possible too. So now you have 2 options what to do with each value.
Third problem: In most cases, guessing a type by the value might work. YES seems to be a boolean, 47 an int, foobar a name - or is it a file? - but often a wider type is possible too, so YES can be just a string or a file, 47.3 might be valid where 47 is or might be not and so on.
However, for experimenting and trying things out, select and grep might be a start:
select line in $(grep "=" sample.conf) "write" "abort"
do
case $line in
"write") echo write; break ;;
"abort") echo abort; break ;;
'#'*=*) echo activate $line;;
*=[0-9]*) echo int value $line;;
*=YES|NO) echo boolean value $line;;
*) echo text value $line ;;
esac
done
Instead of 'echo intvalue $line' you would probably call a function "intconfigure" where only int values are accepted. For "write", you would write back to the file, but I omitted, conserving the comments without assignment and sorting them in again at the right position has to be done, which isn't trivial, given the opportunity to activate or deactivate comments.
But read up on the select command in shell and try it out and see how far you come.
If you think you have reached a usable solution, use this for all your configuration files privately and see, whether you prefer it over using a simple editor or not.
I have a python script that is pulling URLs from pastebin.com/archive, which has links to pastes (which have 8 random digits after pastbin.com in the url). My current output is a .txt with the below data in it, I only want the links to pastes present (Example: http://pastebin.com///Y5JhyKQT) and not links to other pages such as pastebin.com/tools). This is so I can set wget to go pull each individual paste.
The only way I can think of doing this is writing a bash script to count the number of characters in each line and only keep lines with 30 characters exactly (this is the length of the URLs linking to pastes).
I have no idea how I'd go about implementing something like this using grep or awk, perhaps using a while do loop? Any help would be appreciated!
http://pastebin.com///tools
http://pastebin.com//top.location.href
http://pastebin.com///trends
http://pastebin.com///Y5JhyKQT <<< I want to keep this
http://pastebin.com//=
http://pastebin.com///>
From the sample you posted it looks like all you need is:
grep -E '/[[:alnum:]]{8}$' file
or maybe:
grep -E '^.{30}$' file
If that doesn't work for you, explain why and provide a better sample.
This is the algorithm
Find all characters between new line characters or read one line at a time.
Count them or store them in variable and get its count. This is the length of your line.
Only process those lines that are exactly same count as you want.
In python there is both functions character count of string and reading line as well.
#!/usr/bin/env zsh
while read aline
do
if [[ ${#aline} == 30 ]]; then
#do something
fi
done
This is documented in the bash man pages under the "Parameter Expansion" section.
EDIT=this solution is zsh-only
I have a folder of files which need to be renamed.
Instead of a simple incrimental numeric rename function I need to first provide a naming convention which will then incriment in order to ensure file name integrity within the folder.
say i have files:
wei12346.txt
wifr5678.txt
dkgj5678.txt
which need to be renamed to:
Eac-345-018.txt
Eac-345-019.txt
Eac-345-020.txt
Each time i run the script the naming could be different and the numeric incriment to go along with it may also be ddifferent:
Ebc-345-010.pdf
Ebc-345-011.pdf
Ebc-345-012.pdf
So i need to ask for a provided parameter from the user, i was thinking this might be useful as the previous file name in the list of files to be indexed eg: Eac-345-017.txt
The other thing I am unsure about with the incriment is how the script would deal with incrimenting 099 to 100 or 999 to 1000 as i am not aware of how this process is carried out.
I have been told that this is an easy script in perl however I am running cygwin on a windows machine in work and have access to only bash and windows shells in order to execute the script.
Any pointers to get me going would be greatly appreciated, i have some experience programming but scripting is almost entirely new.
Thanks,
Craig
(i understand there are allot of posts on this type of thing already but none seem to offer any concise answer, hence my question)
#!/bin/bash
prefix="$1"
shift
base_n="$1"
shift
step="$1"
shift
n=$base_n
for file in "$#" ; do
formatted_n=$(printf "%03d" $n)
# re-use original file extension whilke we're at it.
mv "$file" "${prefix}-${formatted_n}.${file##*.}"
let n=n+$step
done
Save the file, invoke it like this:
bash fancy_rename.sh Ebc-345- 10 1 /path/to/files/*
Note: In your example you "renamed" a .txt to a .pdf, but above I presumed the extension would stay the same. If you really wanted to just change the extension then it would be a trivial change. If you wanted to actually convert the file format then it would be a little more complex.
Note also that I have formatted the incrementing number with %03d. This means that your number sequence will be e.g.
010
011
012
...
099
100
101
...
999
1000
Meaning that it will be zero padded to three places but will automatically overflow if the number is larger. If you prefer consistency (always 4 digits) you should change the padding to %04d.
OK, you can do the following. You can ask the user first the prefix and then the starting sequence number. Then, you can use the built-in printf from bash to do the correct formatting on the numbers, but you may have to decide to provide enough number width to hold all the sequence, because this will result in a more homogeneous names. You can use read to read user input:
echo -n "Insert the prefix: "
read prefix
echo -n "Insert the sequence number: "
read sn
for i in * ; do
fp=`printf %04d $sn`
mv "$i" "$prefix-$fp.txt"
sn=`expr $sn + 1`
done
Note: You can extract the extension also. That wouldn't be a problem. Also, here I selected 4 numbers fot the sequence number, calculated into the variable $fp.