I want to extract some data from a file and save it in an array, but i don't know how to do it.
In the following I'm extracting some data from /etc/group and save it in another file, after that I print every single item:
awk -F: '/^'$GROUP'/ { gsub(/,/,"\n",$4) ; print $4 }' /etc/group > $FILE
for i in `awk '{ print $0 }' $FILE`
do
echo "member: "$i" "
done
However, I don't want to extract the data into a file, but into an array.
members=( $(awk -F: '/^'$GROUP':/ { gsub(/,/,"\n",$4) ; print $4 }' /etc/group) )
The assignment with the parentheses indicates that $members is an array. The original awk command has been enclosed in $(...), and the colon added so that if you have group and group1 in the file, and you look for group, you don't get the data for group1 too. Of course, if you wanted both entries, then you drop the colon I added.
j=0
for i in `awk '{ print $0 }' $FILE`
do
arr[$j] = $i
j=`expr $j + 1`
done
arr=($(awk -F: -v g=$GROUP '$1 == g { gsub(/,/,"\n",$4) ; print $4 }' /etc/group))
Related
I am facing some issue when I am reading the 3rd word(a hex string) of each line in a text file and compare it with a hex number. Can some one please help me on it.
#!/bin/bash
A=$1
cat $A | while read a; do
a1=$(echo \""$a"\" | awk '{ print $3 }')
#echo $a > cut -d " " -f 3
echo $a1
(("$a1" == 0x10F7))
echo $?
done
But when I use below, the comparison happens correctly,
a1= 0xADCAFE
(( "$a1" == 0x10F7 ))
echo $?
Then why it is showing issue when I read like below,
a1=$(echo \""$a"\" | awk '{ print $3 }')
or> a1=$(echo $a | awk '{ print $3 }')
echo $a prints intended hex value, but comparison does not happen.
Regards,
Running Awk inside a while read loop is an antipattern. Just do the loop in Awk; it's good at that.
awk '$3 == 4343' "$1"
If you want to compare against a string whose value is "0x10F7" then it's
awk '$3 == "0x10F7"' "$1"
If you want to match either, case insensitively etc, a regex is a good way to do that.
awk '$3 ~ /^(0x10[Ff]7|4343)$/' "$1"
Notice how the $1 in double quotes is handled by the shell, and gets replaced by a (properly quoted!) copy of the script's first command-line argument before Awk runs, while the Awk script in single quotes has its own namespace, so $3 is an Awk variable which refers to the third field in the current input line.
Either way, avoid the useless use of cat and always always always quote variables which contain file names with double quotes.
That's literal double quotes. You seem to have tried both a dangerous bare $a and a doubly double-quoted "\"$a\"" where the simple "$a" would be what you actually want.
Thank you all for your responses, Now my script is working fine. I was trying to match two files, below script does the purpose
#!/bin/bash
A=$1
B=$2
dos2unix -f "$A"
dos2unix -f "$B"
rm search_match.txt search_data_match.txt search_nomatch.txt search_data_nomatch.txt
while read line;do
search_word=$(echo $line | awk '{ print $1 }')
grep "$search_word" $B >> temp_file.txt
while read var;do
file1_hex=$(echo $line | awk '{ print $2 }')
file2_hex=$(echo $var | awk '{ print $3 }')
(("$file1_hex" == "$file2_hex"))
zero=$(echo $?)
if [ "$zero" -eq 0 ] ; then
echo $line >> search_match.txt
echo $var >> search_data_match.txt
else
echo $line >> search_nomatch.txt
echo $var >> search_data_nomatch.txt
fi
done < "temp_file.txt"
rm temp_file.txt
done < "$A"
I am working on a shell script that converts exported Microsoft in-addr.apra.txt files to a more useful format so that i can use it in the future in other products for automation purposes. No i am figuring a problem which (im not a programmer) can not solve in a simple way.
Sample script
x=123.223.224
rev $x
gives me
422.322.321
but i want to have the output as follow:
224.223.123
is there a easy way to do it without rev or putting each group in a variable? Or is there a sample i can use? or maybe i use the wrong tools to do it?
Using awk:
x='123.223.224'
awk 'BEGIN{FS=OFS="."} {for (i=NF; i>=2; i--) printf $i OFS; print $1}' <<< "$x"
224.223.123
Use awk for this!
If your text file always contains three octets, simply use . as separator:
echo $x | awk -F. '{ print $3 "." $2 "." $1 }'
For more complex cases, use internal split():
echo $x | awk '{
n = split($0, a, ".");
for(i = n; i > 1; i--) {
printf "%s.", a[i];
}
print a[1]; }'
In this sample split() will split every line (which is passed as argument $0) using delimiter ., saves resulting array into a and returns length of that array (which is saved to n). Note that unlike C,
split() array indexes are starting with one.
Or python:
python -c "print '.'.join(reversed('$x'.split('.')))"
Here is my script.
#!/bin/sh
value=$1
delim=$2
total_fields=$(echo "$value" | tr -cd $2 | wc -c)
let total_fields=total_fields+1
i=1
reverse_value=""
while [ $total_fields -gt 0 ]; do
cur_value=$(echo "$value" | cut -d${delim} -f${total_fields})
if [ $total_fields -ne 1 ]; then
cur_value="$cur_value${delim}"
fi
#echo "$cur_value"
reverse_value="$reverse_value$cur_value"
#echo "$i --> $reverse_value"
let total_fields=total_fields-1
done
echo "$reverse_value"
Using a few small tools.
tr '.' '\n' <<< "$x" | tac | paste -sd.
224.223.123
I hope you can help me.
I try to separate a String:
#!/bin/bash
file=$(<sample.txt)
echo "$file"
The File itself contains Values like this:
(;FF[4]GM[1]SZ[19]CA[UTF-8]SO[sometext]BC[cn]WC[ja]
What I need is a way to extract the Values between the [ ] and set them as variables, for Example:
$FF=4
$GM=1
$SZ=19
and so on
However, some Files do not contain all Values, so that in some cases there is no FF[*]. In this case the Program should use the Value of "99"
How do I have to do this?
Thank you so much for your help.
Greetings
Chris
It may be a bit overcomplicated, but here it comes another way:
grep -Po '[-a-zA-Z0-9]*' file | awk '!(NR%2) {printf "declare %s=\"%s\";\n", a,$0; next} {a=$0} | bash
By steps
Filter file by printing only the needed blocks:
$ grep -Po '[-a-zA-Z0-9]*' a
FF
4
GM
1
SZ
19
CA
UTF-8
SO
sometext
BC
cn
WC
ja
Reformat so that it specifies the declaration:
$ grep -Po '[-a-zA-Z0-9]*' a | awk '!(NR%2) {printf "declare %s=\"%s\";\n", a,$0; next} {a=$0}'
declare FF="4";
declare GM="1";
declare SZ="19";
declare CA="UTF-8";
declare SO="sometext";
declare BC="cn";
declare WC="ja";
And finally pipe to bash so that it is executed.
Note 2nd step could be also rewritten as
xargs -n2 | awk '{print "declare"$1"=\""$2"\";"}'
I'd write this, using ; or [ or ] as awk's field separators
$ line='(;FF[4]GM[1]SZ[19]CA[UTF-8]SO[sometext]BC[cn]WC[ja]'
$ awk -F '[][;]' '{for (i=2; i<NF; i+=2) {printf "%s=\"%s\" ", $i, $(i+1)}; print ""}' <<<"$line"
FF="4" GM="1" SZ="19" CA="UTF-8" SO="sometext" BC="cn" WC="ja"
Then, to evaluate the output in your current shell:
$ source <(!!)
source <(awk -F '[][;]' '{for (i=2; i<NF; i+=2) {printf "%s=\"%s\" ", $i, $(i+1)}; print ""}' <<<"$line")
$ echo $SO
sometext
To handle the default FF value:
$ source <(awk -F '[][;]' '{
print "FF=99"
for (i=2; i<NF; i+=2) printf "%s=\"%s\" ", $i, $(i+1)
print ""
}' <<< "(;A[1]B[2]")
$ echo $FF
99
$ source <(awk -F '[][;]' '{
print "FF=99"
for (i=2; i<NF; i+=2) printf "%s=\"%s\" ", $i, $(i+1)
print ""
}' <<< "(;A[1]B[2]FF[3]")
$ echo $FF
3
Per your request:
while IFS=\[ read -r A B; do
[[ -z $B ]] && B=99
eval "$A=\$B"
done < <(exec grep -oE '[[:alpha:]]+\[[^]]*' sample.txt)
Although using an associative array would be better:
declare -A VALUES
while IFS=\[ read -r A B; do
[[ -z $B ]] && B=99
VALUES[$A]=$B
done < <(exec grep -oE '[[:alpha:]]+\[[^]]*' sample.txt)
There you could have access both with keys ("${!VALUES[#]}") and values "${VALUES['FF']}".
I would probably do something like this:
set $(sed -e 's/^(;//' sample.txt | tr '[][]' ' ')
while (( $# > 2 ))
do
varname=${1}
varvalue=${2}
# do something to test varname and varvalue to make sure they're sane/safe
declare "${varname}=${varvalue}"
shift 2
done
i have an input file as follow:
some lines with quote and :
AGE:23
some lines with quote and :
NAME:2,0,"My Name Is"
some lines with quote and :
Actually i use this code to extract information from the file:
age="$(cat "$file" | awk -F ':' '/AGE:/ { print $2 }')"
name="$(cat "$file" | awk -F '"' '/NAME:/ { print $2 }' )"
echo "age: $age"
echo "name: $name"
output:
age: 23
name: My Name Is
i'm searching for a better way to do this than running cat and awk two times. i have search to do it in one cat/awk line but can't figure it out, not appropriated in this case? can anyone point me a better way please ?
Thanks in advance
while IFS=: read key value; do
case $key in
AGE) age=$value;;
NAME) name=$(awk -F'"' '{print $2}' <<< "$value");;
esac
done < "$file"
I like #JohnKugelman's approach, but it can be improved: use colon and quote as the field separators:
while IFS=':"' read -ra fields; do
case ${fields[0]} in
AGE) age=${fields[1]} ;;
NAME) [[ ${fields[1]} == "2,0," ]] && name=${fields[2]} ;;
esac
done < file
With awk, I'd write:
read age name < <(
awk -F '[:,]' '
$1 == "AGE" {printf "%s ",$2}
$1 == "NAME" && $2 == 2 && $3 == 0 {printf "%s ",$NF}
END {print ""}
' filename
)
If the data is simple as you have shown in your question. No need to use shell for this , just awk will be more than enough
awk -F '"' '/AGE/{print tolower($0)}/NAME/{print "name:"$2}' input.txt
I am trying to search for a pattern and from the results i am extracting just the second column. The command works well in command line but not inside a bash script.
#!/bin/bash
set a = grep 'NM_033356' test.txt | awk '{ print $2 }'
echo $a
It doesnt print any output at all.
Input
NM_033356 2
NM_033356 5
NM_033356 7
Your code:
#!/bin/bash
set a = grep 'NM_033356' test.txt | awk '{ print $2 }'
echo $a
Change it to:
#!/bin/bash
a="$(awk '$1=="NM_033356"{ print $2 }' test.txt)"
echo "$a"
Code changes are based on your sample input.
.......
a="$(awk '/NM_033356/ { print $2 }' test.txt)"
Try this:
a=`grep 'NM_033356' test.txt | awk '{ print $2 }'`