how to parse a string in Shell script - shell

I want to parse the following string in shell script.
VERSION=2.6.32.54-0.11.def
Here I want to get two value.
first = 263254
second = 11
I am using following to get the first value:
first=`expr substr $VERSION 1 9| sed "s/\.//g" |sed "s/\-//g"`
to get the second:
second=`expr substr $VERSION 10 6| sed "s/\.//g" |sed "s/\-//g"`
Using above code the output is:
first=263254
second=11
The result wont be consistent if version is changed to:
VERSION=2.6.32.54-0.1.def
Here second value will become 1d, but I want it give output of 1 only.
How can I directly parse the number after '-' and before '.d'?

$ first=$(echo $VERSION | cut -d- -f1 | sed 's/\.//g')
$ second=$(echo $VERSION | cut -d- -f2 | cut -d. -f2)

$ first=$(echo $VERSION | cut -d- -f1 | tr -d '.')
$ second=$(echo $VERSION | cut -d- -f2 | cut -d. -f2)
$ echo $first
263254
$ echo $second
11

you don't need multiple processes (sed|sed|sed...). single process with awk should work.
if you have VERSION=xxxx as string:
to get the first:
awk -F'[-=]' '{gsub(/\./,"",$2)}$0=$2'
to get the second:
awk -F'-|\\.def' '{split($2,a,".")}$0=a[2]'
test:
first:
kent$ echo "VERSION=2.6.32.54-0.1.def"|awk -F'[-=]' '{gsub(/\./,"",$2)}$0=$2'
263254
second
kent$ echo "VERSION=2.6.32.54-0.1.def"|awk -F'-|\\.def' '{split($2,a,".")}$0=a[2]'
1
kent$ echo "VERSION=2.6.32.54-0.1234.def"|awk -F'-|\\.def' '{split($2,a,".")}$0=a[2]'
1234
if you have VERSION=xxx as variable $VERSION:
first:
awk -F'-' '{gsub(/\./,"",$1)}$0=$1'
second:
awk -F'-|\\.def' '{split($2,a,".")}$0=a[2]'
test:
VERSION=2.6.32.54-0.1234.def
kent$ echo $VERSION|awk -F'-' '{gsub(/\./,"",$1)}$0=$1'
263254
7pLaptop 11:18:22 /tmp/test
kent$ echo $VERSION|awk -F'-|\\.def' '{split($2,a,".")}$0=a[2]'
1234

You should use regular expressions instead of the number of characters.
first=`sed 's/.//g' | sed 's/\(.*\)-.*/\1/'`
second=`sed 's/.//g' | sed 's/.*-\([0-9]*\).*/\1/'`
\(...\) are used to create a capturing group, and \1 output this group.

first=$(echo ${VERSION} | sed -e 's/^\([^-]*\)-0\.\([0-9]*\)\.def/\1/' -e 's/\.//g')
second=$(echo ${VERSION} | sed -e 's/^\([^-]*\)-0\.\([0-9]*\)\.def/\2/' -e 's/\.//g')

$ first=$(echo $VERSION | awk -F"\." '{gsub(/-.*/,"",$4);print $1$2$3$4}')
$ second=$(echo $VERSION | awk -F"\." '{print $5}' )

Related

How to remove first & last character in bash string

#!/bin/bash
MA=$(bt-device -l | cut -d " " -f 3)
MAC=${MA:1: -1}
bluetoothctl connect $MAC
Expected Result
98:9E:63:18:00:88
Actual result
(98:9E:63:18:00:88
A few alternatives:
$ echo 'Denny’s Tunez (98:9E:63:18:00:88)' | sed -En 's/^[^(]*\(([^)]*)\).*/\1/p'
98:9E:63:18:00:88
$ echo 'Denny’s Tunez (98:9E:63:18:00:88)' | cut -d'(' -f2 | cut -d')' -f1
98:9E:63:18:00:88
$ echo 'Denny’s Tunez (98:9E:63:18:00:88)' | awk -F'[)(]' '{print $2}'
98:9E:63:18:00:88
$ echo 'Denny’s Tunez (98:9E:63:18:00:88)' | grep -Eow '(..)(:..){5}'
98:9E:63:18:00:88
$ x='Denny’s Tunez (98:9E:63:18:00:88)'
$ y="${x//*\(/}"
$ y="${y//\)*}"
$ echo $y
98:9E:63:18:00:88
With GNU bash and its Parameter Expansion:
s="(98:9E:63:18:00:88)"
s="${s/#?/}" # remove first character
s="${s/%?/}" # remove last character
echo "$s"
Output:
98:9E:63:18:00:88
Using sed it can be done in a single step:
s='Denny’s Tunez (98:9E:63:18:00:88)'
echo "$s" | sed -E 's/.* \(|)//g'
98:9E:63:18:00:88
So for your example you can use:
mac=$(bt-device -l | sed -E 's/.* \(|)//g')
You can use parameter expansion:
offset and length
echo ${MA:1: -1}
prefix and suffix removal
tmp=${MA#(}
echo ${tmp%)}
parameter matching
tmp=${MA/#\(}
echo ${tmp/%\)}
Another approach is to:
whitelist what you do want
echo "$MA" | tr -dC '[0-9A-F:]'

How to get version number from string in bash

I have a variable having following format
bundle="chn-pro-X.Y-Z.el8.x86_64"
X,Y,Z are numbers having any number of digits
Ex:
1.0-2 # X=1 Y=0 Z=2
12.45-9874 # X=12 Y=45 Z=9874
How can I grab X.Y and store it in another variable?
EDIT:
I wasn't right with my wording, but
I want to store X.Y into new variable not individual X & Y's
I'm looking to finally have a variable version which has X.Y grabbed from bundle:
version="X.Y"
I would use awk:
bundle="chn-pro-12.45-9874.el8.x86_64"
echo "$bundle" | awk -F "[.-]" '{print $3,$4,$5}'
12 45 9874
Now if you want to assign to x, y, z use read and process substitution:
read -r x y z < <(echo "$bundle" | awk -F "[.-]" '{print $3,$4,$5}')
echo "x=$x, y=$y, z=$z"
x=12, y=45, z=9874
If you just want the value of X.Y as a single value this is still great use for awk:
bundle="chn-pro-12.45-9874.el8.x86_64"
echo "$bundle" | awk -F "[-]" '{print $3}'
12.45
And if you then want to put that into a variable:
x_y=$(echo "$bundle" | awk -F "[-]" '{print $3}')
echo "x_y=$x_y"
x_y=12.45
Or you can use cut in this case to get the third field:
echo "$bundle" | cut -d- -f3
12.45
Like that:
$ bundle="chn-pro-1.0-2.el8.x86_64"
$ X="$(echo "$bundle" | cut -d . -f1 | cut -d- -f3)"
$ Y="$(echo "$bundle" | cut -d . -f2 | cut -d- -f1)"
$ Z="$(echo "$bundle" | cut -d . -f2 | cut -d- -f2)"
$ echo "$X"
1
$ echo "$Y"
0
$ echo "$Z"
2
You can merge X and Y into a single variable:
$ XY="$X.$Y"
$ echo $XY
1.0
Use regex to separate numbers:
numbers=$(echo $bundle | grep -Eo '([0-9]+\.[0-9]+\-[0-9]+)' | sed 's/\./\t/g;s/\-/\t/g')
Then assign them to variables with using awk or tr or cut, whatever you want:
X=$(echo $numbers| awk '{print $1}')
Y=$(echo $numbers| awk '{print $2}')
Z=$(echo $numbers| awk '{print $3}')
EDIT
For storing x.y into single version variable you can simply ignore pervios commands:
version=$(echo $bundle | grep -Eo '([0-9]+\.[0-9]+\-[0-9]+)' | grep -Eo '([0-9]+\.[0-9]+)')
Given this input:
$ bundle="chn-pro-12.45-9874.el8.x86_64"
using GNU or BSD sed for -E:
$ foo=$(echo "$bundle" | sed -E 's/.*-([0-9]+\.[0-9]+)-[0-9].*/\1/')
$ echo "$foo"
12.45
or with any sed:
$ foo=$(echo "$bundle" | sed 's/.*-\([0-9][0-9]*\.[0-9][0-9]*\)-[0-9].*/\1/')
$ echo "$foo"
12.45
Assumptions:
the input string will always contain (at least) 3 hyphens
the desired version string will always reside between the 2nd and 3rd hyphens of the input string
we need to maintain the input string (ie, don't clobber/overwrite the variable containing the input string)
We can eliminate the subprocess calls (necessary for echo/sed/grep/awk/sed) by using some parameter expansions:
$ bundle="chn-pro-X.Y-Z.el8.x86_64"
$ temp="${bundle#*-}" # strip off 1st hyphen delimited string
$ echo "${temp}"
pro-X.Y-Z.el8.x86_64
$ temp="${temp#*-}" # strip off 2nd hyphen delimited string
$ echo "${temp}"
X.Y-Z.el8.x86_64
$ version="${temp%%-*}" # save 3rd hyphen delimited string (aka our version)
$ echo "${version}"
X.Y
NOTE: We can eliminate the temp variable by replacing all occurrences of temp with version with the understanding version does not contain what we want until after the 3rd parameter expansion has occurred, eg:
$ bundle="chn-pro-X.Y-Z.el8.x86_64"
$ version="${bundle#*-}"
$ version="${version#*-}"
$ version="${version%%-*}"
$ echo "${version}"
X.Y

How to print before and after dot text Unix

I am trying to print only specific output from sentence like below
Before and after dot text should be printed
InputVar="ABC SDFSG XYZ.AFGAJK JKK"
Expected output :
XYZ.AFGAJK
I am using cut command not working
echo "$InputVar" | cut -d'' -f2
Any other approach ?
Here are a few suggestions. awk with RS set to a space seems easiest. YMMV
$ echo "$InputVar" | cut -d ' ' -f 3
XYZ.AFGAJK
$ echo "$InputVar" | awk '/\./' RS=' '
XYZ.AFGAJK
$ echo "$InputVar" | awk '{for(i=1;i<=NF;i++) if(match($i,"\\.")) print $i}'
XYZ.AFGAJK
$ echo "$InputVar" | sed -n 's/.* \([^ .]*[.][^ .]*\) .*/\1/p'
XYZ.AFGAJK
Using cut:
If you really want to use cut, then you could try:
echo "$InputVar" | cut -d' ' -f3
Which uses a space character as a delimiter (you originally had an empty string, which is not allowed), and extracts field 3 rather than field 2.
Using grep:
You can use grep rather than cut, to match & extract specifically what you want:
echo "$InputVar" | grep -Eo '[^ ]+\.[^ ]+'
Explanation:
The -E option is for extended regex
The -o option is for extracting the matched component only
The regex matches a literal ., surrounded by a non-empty sequence of non-space characters
Comparing the two methods:
Either of these will work with your shown example. But, suppose the input string was instead:
InputVar="ABC SDFSG XYZ.AFGAJK JKK XYZ.ABC"
The version using grep would give all the matches (a literal . with non-space characters on either side).
Using cut however, you would need to specify the specific fields you want, i.e.
$ echo "$InputVar" | cut -d' ' -f3,5
XYZ.AFGAJK
XYZ.ABC
If you instead wanted just the n-th match, using the grep approach, you could use sed to select the n-th match, e.g.
$ echo "$InputVar" | grep -Eo '[^ ]+\.[^ ]+'
XYZ.AFGAJK
XYZ.ABC
$ echo "$InputVar" | grep -Eo '[^ ]+\.[^ ]+' | sed '1q;d'
XYZ.AFGAJK
$ echo "$InputVar" | grep -Eo '[^ ]+\.[^ ]+' | sed '2q;d'
XYZ.ABC

How to trim a string in shell script

I have a string,
var=refs/heads/testing/branch
I want to get rid of refs/heads/ in the string using shell script, such that I have only:
var=testing/branch
Commands I tried (one per line):
echo $(var) | awk -F\\ {'print $2'}
echo $var | sed -e s,refs/heads/,,
echo "refs/heads/testing/branch" | grep -oP '(?<=refs/heads/\)\w+'
echo "refs/heads/testing/branch" | LC_ALL=C sed -e 's/.*\\//'
echo "refs/heads/testing/branch" | cut -d'\' -f2
echo refs/heads/testing/branch | sed -e s,refs/heads/,,
there are lots of options out there ,try easy ones:
echo $var | cut -d "/" -f 3,4
echo $var | awk -F"/" '{print $3"/"$4}'
Shell parameter expansion: remove the prefix "refs/heads/" from the variable contents
$ var=refs/heads/testing/branch
$ echo "${var#refs/heads/}"
testing/branch

How to get nth line of a file in bash?

I want to extract from a file named datax.txt the second line being :
0/0/0/0/0/0 | 0/0/0/0/0/0 | 0/0/0/0/0/0
And then I want to store in 3 variables the 3 sequences 0/0/0/0/0/0.
How am I supposed to do?
Read the 2nd line into variables a,b and c.
read a b c <<< $(awk -F'|' 'NR==2{print $1 $2 $3}' datax)
the keys is to split the problem in two:
you want to get the nth line of a file -> see here
you want to split a line in chunks according to a delimiter -> that's the job of many tools, cut is one of them
For future questions, be sure to include a more complete dataset, here is one for now. I changed a bit the second line so that we can verify that we got the right column:
f.txt
4/4/4/4/4/4 | 4/4/4/4/4/4 | 4/4/4/4/4/4
0/0/0/0/a/0 | 0/0/0/0/b/0 | 0/0/0/0/c/0
8/8/8/8/8/8 | 8/8/8/8/8/8 | 8/8/8/8/8/8
8/8/8/8/8/8 | 8/8/8/8/8/8 | 8/8/8/8/8/8
Then a proper script building on the two key actions described above:
extract.bash
file=$1
target_line=2
# get the n-th line
# https://stackoverflow.com/questions/6022384/bash-tool-to-get-nth-line-from-a-file
line=$(cat $file | head -n $target_line | tail -1)
# get the n-th field on a line, using delimiter '|'
var1=$(echo $line | cut --delimiter='|' --fields=1)
echo $var1
var2=$(echo $line | cut --delimiter='|' --fields=2)
echo $var2
var3=$(echo $line | cut --delimiter='|' --fields=3)
echo $var3
aaand:
$ ./extract.bash f.txt
0/0/0/0/a/0
0/0/0/0/b/0
0/0/0/0/c/0
Please try the following:
IFS='|' read a b c < <(sed -n 2P < datax | tr -d ' ')
Then the variables a, b and c are assigned to each field of the 2nd line.
You can use sed to print a specific line of a file, so for your example on the second line:
sed -n -e 2p ./datax
Set the output of the sed to be a variable:
Var=$(sed -n -e 2p ./datax)
Then split the string into the 3 variables you need:
A="$(echo $Var | cut -d'|' -f1)"
B="$(echo $Var | cut -d'|' -f2)"
C="$(echo $Var | cut -d'|' -f3)"

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