So I have a file of "keys", for example:
key1
key2
key3
and I have a file of key:value pairs:
key1:value1
key2:value2
key3:value3
I want to replace the keys in my file of keys with their corresponding values in the key:value file. So the file of keys will look like this when complete:
value1
value2
value3
...
What is the best way to do this in bash? Note that a key may appear more than once in the keys file, but should only appear once in the key:values file.
if the join command is available in your environment, the following should work. The addition of an index via the awk command is needed to restore original key order (via a Schwartzian transform).
join -o 1.1,2.2 -t':' -1 2 -2 1 <(awk '{print(NR":"$0)}' key_file | sort -k2,2 -t':') <(sort -k1,1 -t':' key_values_file) | sort -k1,1 -t':' | cut -f2 -d':'
I know you want "bash" , but this is very simply solved with a quick perl script. Assume you have the files pairs.txt and keys.txt :
use strict;
my %keys2values;
# read through the pairs file to get the key:value mapping
open PAIRS, "cat pairs.txt |" ;
while(<PAIRS>) {
chomp $_;
my ($key,$value) = split(":",$_);
$keys2values{$key} = $value;
}
open KEYS, "cat keys.txt |";
while(<KEYS>) {
chomp $_;
my $key = $_;
if(defined $keys2values{$key}) {
print "$keys2values{$key}\n";
}
# if a key:value pair isn't defined, just print the key
else {
print "$key\n";
}
}
Since I have a thing for pure-bash solutions, I'll just post this solution. It will only work in bash 4+, because it uses associative arrays.
#!/bin/bash
while IFS=: read key value; do
declare -A hash[$key]=$value
done < pairfile
while read key; do
printf '%s\n' "${hash[$key]}"
done < keyfile
Related
I have a file like this:
AAKRKA HIST1H1B AAGAGAAKRKATGPP
AAKRKA HIST1H1E RKSAGAAKRKASGPP
AAKRLN ACAT1 LMTADAAKRLNVTPL
AAKRLN SUCLG2 NEALEAAKRLNAKEI
AAKRLR GTF2F1 VSEMPAAKRLRLDTG
AAKRMA VCL NDIIAAAKRMALLMA
AAKRPL WIZ YLGSVAAKRPLQEDR
AAKRQK MTA2 SSSQPAAKRQKLNPA
I would like to kind of merge 2 lines if they are exactly the same in the 1st column. The desired output is:
AAKRKA HIST1H1B,HIST1H1E AAGAGAAKRKATGPP,RKSAGAAKRKASGPP
AAKRLN ACAT1,SUCLG2 LMTADAAKRLNVTPL,NEALEAAKRLNAKEI
AAKRLR GTF2F1 VSEMPAAKRLRLDTG
AAKRMA VCL NDIIAAAKRMALLMA
AAKRPL WIZ YLGSVAAKRPLQEDR
AAKRQK MTA2 SSSQPAAKRQKLNPA
Sometimes there could be more than two lines starting with the same word. How could I reach the desired output with bash/awk?
Thanks for help!
Since this resembles SQL like group operations, you can use sqlite which is available in bash
with the given inputs
$ cat aqua.txt
AAKRKA HIST1H1B AAGAGAAKRKATGPP
AAKRKA HIST1H1E RKSAGAAKRKASGPP
AAKRLN ACAT1 LMTADAAKRLNVTPL
AAKRLN SUCLG2 NEALEAAKRLNAKEI
AAKRLR GTF2F1 VSEMPAAKRLRLDTG
AAKRMA VCL NDIIAAAKRMALLMA
AAKRPL WIZ YLGSVAAKRPLQEDR
AAKRQK MTA2 SSSQPAAKRQKLNPA
$
Script:
$ cat ./sqlite_join.sh
#!/bin/sh
sqlite3 << EOF
create table data(a,b,c);
.separator ' '
.import $1 data
select a, group_concat(b) , group_concat(c) from data group by a;
EOF
$
Results
$ ./sqlite_join.sh aqua.txt
AAKRKA HIST1H1B,HIST1H1E AAGAGAAKRKATGPP,RKSAGAAKRKASGPP
AAKRLN ACAT1,SUCLG2 LMTADAAKRLNVTPL,NEALEAAKRLNAKEI
AAKRLR GTF2F1 VSEMPAAKRLRLDTG
AAKRMA VCL NDIIAAAKRMALLMA
AAKRPL WIZ YLGSVAAKRPLQEDR
AAKRQK MTA2 SSSQPAAKRQKLNPA
$
This is a two-liner in awk; the first line stores the second and third fields in associative arrays indexed by the first field, accumulating fields with identical indices with leading commas before each field, and the second line iterates over the two arrays, deleting the leading comma on output:
{ second[$1] = second[$1] "," $2; third[$1] = third[$1] "," $3 }
END { for (i in second) print i, substr(second[i],2), substr(third[i],2) }
I made no assumptions about the order of the input or the output. If you want sorted output, pipe the output through sort. You can run the program at https://ideone.com/sbgLNk.
try this:
DATAFILE=data.txt
cut -d " " -f1 < $DATAFILE | sort | uniq |
while read key; do
column1="$key"
column2=""
column3=""
grep "$key" $DATAFILE |
while read line; do
set -- $line
[ -n "$column2" ] && [ -n "$2" ] && column2="$column2,"
[ -n "$column3" ] && [ -n "$3" ] && column3="$column3,"
column2="$column2$2"
column3="$column3$3"
echo "$column1 $column2 $column3"
done | tail -n1
done
There is a Capture the Flag challenge
I have two files; one with scrambled text like this with about 550 entries
dnaoyt
cinuertdso
bda
haey
tolpap
...
The second file is a dictionary with about 9,000 entries
radar
ccd
gcc
fcc
historical
...
The goal is to find the right, unscrambled version of the word, which is contained in the dictionary file.
My approach is to sort the characters from the first word from the first file and then look up if the first word from the second file has the same length. If so then sort that too and compare them.
This is my fully functional bash script, but it is very slow.
#!/bin/bash
while IFS="" read -r p || [ -n "$p" ]
do
var=0
ro=$(echo $p | perl -F -lane 'print sort #F')
len_ro=${#ro}
while IFS="" read -r o || [ -n "$o" ]
do
ro2=$(echo $o | perl -F -lane 'print sort # F')
len_ro2=${#ro2}
let "var+=1"
if [ $len_ro == $len_ro2 ]; then
if [ $ro == $ro2 ]; then
echo $o >> new.txt
echo $var >> whichline.txt
fi
fi
done < dictionary.txt
done < scrambled-words.txt
I have also tried converting all characters to ASCII integers and sum each word, but while comparing I realized that the sum of a different char pattern may have the same sum.
[edit]
For the records:
- no anagrams contained in dictionary
- to get the flag, you need to export the unscrambled words as one blob and ans make a SHA-Hash out of it (thats the flag)
- link to ctf for guy who wanted the files https://challenges.reply.com/tamtamy/user/login.action
You're better off creating a lookup dictionary (keyed by the sorted word) from the dictionary file.
Your loop body is executed 550 * 9,000 = 4,950,000 times (O(N*M)).
The solution I propose executes two loops of at most 9,000 passes each (O(N+M)).
Bonus: It finds all possible solutions at no cost.
#!/usr/bin/perl
use strict;
use warnings qw( all );
use feature qw( say );
my $dict_qfn = "dictionary.txt";
my $scrambled_qfn = "scrambled-words.txt";
sub key { join "", sort split //, $_[0] }
my %dict;
{
open(my $fh, "<", $dict_qfn)
or die("Can't open \"$dict_qfn\": $!\n");
while (<$fh>) {
chomp;
push #{ $dict{key($_)} }, $_;
}
}
{
open(my $fh, "<", $scrambled_qfn)
or die("Can't open \"$scrambled_qfn\": $!\n");
while (<$fh>) {
chomp;
my $matches = $dict{key($_)};
say "$_ matches #$matches" if $matches;
}
}
I wouldn't be surprised if this only takes one millionths of the time of your solution for the sizes you provided (and it scales so much better than yours if you were to increase the sizes).
I would do something like this with gawk
gawk '
NR == FNR {
dict[csort()] = $0
next
}
{
print dict[csort()]
}
function csort( chars, sorted) {
split($0, chars, "")
asort(chars)
for (i in chars)
sorted = sorted chars[i]
return sorted
}' dictionary.txt scrambled-words.txt
Here's perl-free solution I came up with using sort and join:
sort_letters() {
# Splits each letter onto a line, sorts the letters, then joins them
# e.g. "hello" becomes "ehllo"
echo "${1}" | fold-b1 | sort | tr -d '\n'
}
# For each input file...
for input in "dict.txt" "words.txt"; do
# Convert each line to [sorted] [original]
# then sort and save the results with a .sorted extension
while read -r original; do
sorted=$(sort_letters "${original}")
echo "${sorted} ${original}"
done < "${input}" | sort > "${input}.sorted"
done
# Join the two files on the [sorted] word
# outputting the scrambled and unscrambed words
join -j 1 -o 1.2,2.2 "words.txt.sorted" "dict.txt.sorted"
I tried something very alike, but a bit different.
#!/bin/bash
exec 3<scrambled-words.txt
while read -r line <&3; do
printf "%s" ${line} | perl -F -lane 'print sort #F'
done>scrambled-words_sorted.txt
exec 3>&-
exec 3<dictionary.txt
while read -r line <&3; do
printf "%s" ${line} | perl -F -lane 'print sort #F'
done>dictionary_sorted.txt
exec 3>&-
printf "" > whichline.txt
exec 3<scrambled-words_sorted.txt
while read -r line <&3; do
counter="$((++counter))"
grep -n -e "^${line}$" dictionary_sorted.txt | cut -d ':' -f 1 | tr -d '\n' >>whichline.txt printf "\n" >>whichline.txt
done
exec 3>&-
As you can see I don't create a new.txt file; instead I only create whichline.txt with a blank line where the word doesn't match. You can easily paste them up to create new.txt.
The logic behind the script is nearly the logic behind yours, with the exception that I called perl less times and I save two support files.
I think (but I am not sure) that creating them and cycle only one file will be better than ~5kk calls of perl. This way "only" ~10k times is called.
Finally, I decided to use grep because it's (maybe) the fastest regex matcher, and searching for the entire line the lenght is intrinsic in the regex.
Please, note that what #benjamin-w said is still valid and, in that case, grep will reply badly and I did not managed it!
I hope this could help [:
I have a file called list_of_files.txt which is a list of over 500 other files. It looks like so:
list1.txt
list2.txt
list3.txt
etc
This lists all look like so: (all columns are made of numerical values)
value1 value2 value3
value4 value5 value6
etc
For each of those lists, I want to cut a certain column of interest, sort it so that number are in increasing order and check whether my original file and new one have the same order.
I tried making a loop .sh script like so:
for i in list_of_files.txt
do
cut -f3 -d " " list*.txt > chr*_all_positions.txt
sort -n chr*_all_positions.txt > chr*_ordered_positions.txt
diff chr*_all_positions.txt chr*_ordered_positions.txt > result_*.txt
done
However, this does not work. Any help would be appreciated.
Loop over the numbers, not the file names:
i=1
while [[ -f list$i.txt ]] ; do
cut -f3 -d " " list$i.txt > chr$i\_all_positions.txt
sort -n chr$i\_all_positions.txt > chr$i\_ordered_positions.txt
diff chr$i\_all_positions.txt chr$i\_ordered_positions.txt > result_$i.txt
((i++))
done
Also, you can use sort -c or sort -C to check whether the output is sorted without the need to create the _ordered file.
Using readarray and array
readarray -t arrname < list_of_files.txt
for filename in "${arrname[#]}"; do
...
done
Using read builtin
while read filename; do
...
done < list_of_files.txt
I have 2 files refer.txt and parse.txt
refer.txt contains the following
julie,remo,rob,whitney,james
parse.txt contains
remo/hello/1.0,remo/hello2/2.0,remo/hello3/3.0,whitney/hello/1.0,julie/hello/2.0,julie/hello/3.0,rob/hello/4.0,james/hello/6.0
Now my output.txt should list the files in parse.txt based on the order specified in refer.txt
ex of output.txt should be:
julie/hello/2.0,julie/hello/3.0,remo/hello/1.0,remo/hello2/2.0,remo/hello3/3.0,rob/hello/4.0,whitney/hello/1.0,james/hello/6.0
i have tried the following code:
sort -nru refer.txt parse.txt
but no luck.
please assist me.TIA
You can do that using gnu-awk:
awk -F/ -v RS=',|\n' 'FNR==NR{a[$1] = (a[$1])? a[$1] "," $0 : $0 ; next}
{s = (s)? s "," a[$1] : a[$1]} END{print s}' parse.txt refer.txt
Output:
julie/hello/2.0,julie/hello/3.0,remo/hello/1.0,remo/hello2/2.0,remo/hello3/3.0,rob/hello/4.0,whitney/hello/1.0,james/hello/6.0
Explanation:
-F/ # Use field separator as /
-v RS=',|\n' # Use record separator as comma or newline
NR == FNR { # While processing parse.txt
a[$1]=(a[$1])?a[$1] ","$0:$0 # create an array with 1st field as key and value as all the
# records with keys julie, remo, rob etc.
}
{ # while processing the second file refer.txt
s = (s)?s "," a[$1]:a[$1] # aggregate all values by reading key from 2nd file
}
END {print s } # print all the values
In pure native bash (4.x):
# read each file into an array
IFS=, read -r -a values <parse.txt
IFS=, read -r -a ordering <refer.txt
# create a map from content before "/" to comma-separated full values in preserved order
declare -A kv=( )
for value in "${values[#]}"; do
key=${value%%/*}
if [[ ${kv[$key]} ]]; then
kv[$key]+=",$value" # already exists, comma-separate
else
kv[$key]="$value"
fi
done
# go through refer list, putting full value into "out" array for each entry
out=( )
for value in "${ordering[#]}"; do
out+=( "${kv[$value]}" )
done
# print "out" array in comma-separated form
IFS=,
printf '%s\n' "${out[*]}" >output.txt
If you're getting more output fields than you have input fields, you're probably trying to run this with bash 3.x. Since associative array support is mandatory for correct operation, this won't work.
tr , "\n" refer.txt | cat -n >person_id.txt # 'cut -n' not posix, use sed and paste
cat person_id.txt | while read person_id person_key
do
print "$person_id" > $person_key
done
tr , "\n" parse.txt | sed 's/(^[^\/]*)(\/.*)$/\1 \1\2/' >person_data.txt
cat person_data.txt | while read foreign_key person_data
do
person_id="$(<$foreign_key)"
print "$person_id" " " "$person_data" >>merge.txt
done
sort merge.txt >output.txt
A text book data processing approach, a person id table, a person data table, merged on a common key field, which is the first name of the person:
[person_key] [person_id]
- person id table, a unique sortable 'id' for each person (line number in this instance, since that is the desired sort order), and key for each person (their first name)
[person_key] [person_data]
- person data table, the data for each person indexed by 'person_key'
[person_id] [person_data]
- a merge of the 'person_id' table and 'person_data' table on 'person_key', which can then be sorted on person_id, giving the output as requested
The trick is to implement an associative array using files, the file name being the key (in this instance 'person_key'), the content being the value. [Essentially a random access file implemented using the filesystem.]
This actually adds a step to the otherwise simple but not very efficient task of grepping parse.txt with each value in refer.txt - which is more efficient I'm not sure.
NB: The above code is very unlikely to work out of the box.
NBB: On reflection, probably a better way of doing this would be to use the file system to create a random access file of parse.txt (essentially an index), and to then consider refer.txt as a batch file, submitting it as a job as such, printing out from the parse.txt random access file the data for each of the names read in from refer.txt in turn:
# 1) index data file on required field
cat person_data.txt | while read data
do
key="$(print "$data" | sed 's/(^[^\/]*)/\1/')" # alt. `cut -d'/' -f1` ??
print "$data" >>./person_data/"$key"
done
# 2) run batch job
cat refer_data.txt | while read key
do
print ./person_data/"$key"
done
However having said that, using egrep is probably just as rigorous a solution or at least for small datasets, I would most certainly use this approach given the specific question posed. (Or maybe not! The above could well prove faster as well as being more robust.)
Command
while read line; do
grep -w "^$line" <(tr , "\n" < parse.txt)
done < <(tr , "\n" < refer.txt) | paste -s -d , -
Key points
For both files, newlines are translated to commas using the tr command (without actually changing the files themselves). This is useful because while read and grep work under the assumption that your records are separated by newlines instead of commas.
while read will read in every name from refer.txt, (i.e julie, remo, etc.) and then use grep to retrieve lines from parse.txt containing that name.
The ^ in the regex ensures matching is only performed from the start of the string and not in the middle (thanks to #CharlesDuffy's comment below), and the -w option for grep allows whole-word matching only. For example, this ensures that "rob" only matches "rob/..." and not "robby/..." or "throb/...".
The paste command at the end will comma-separate the results. Removing this command will print each result on its own line.
I have a bunch of different kinds of files I need to look at periodically, and what they have in common is that the lines have a bunch of key=value type strings. So something like:
Version=2 Len=17 Hello Var=Howdy Other
I would like to be able to reference the names directly from awk... so something like:
cat some_file | ... | awk '{print Var, $5}' # prints Howdy Other
How can I go about doing that?
The closest you can get is to parse the variables into an associative array first thing every line. That is to say,
awk '{ delete vars; for(i = 1; i <= NF; ++i) { n = index($i, "="); if(n) { vars[substr($i, 1, n - 1)] = substr($i, n + 1) } } Var = vars["Var"] } { print Var, $5 }'
More readably:
{
delete vars; # clean up previous variable values
for(i = 1; i <= NF; ++i) { # walk through fields
n = index($i, "="); # search for =
if(n) { # if there is one:
# remember value by name. The reason I use
# substr over split is the possibility of
# something like Var=foo=bar=baz (that will
# be parsed into a variable Var with the
# value "foo=bar=baz" this way).
vars[substr($i, 1, n - 1)] = substr($i, n + 1)
}
}
# if you know precisely what variable names you expect to get, you can
# assign to them here:
Var = vars["Var"]
Version = vars["Version"]
Len = vars["Len"]
}
{
print Var, $5 # then use them in the rest of the code
}
$ cat file | sed -r 's/[[:alnum:]]+=/\n&/g' | awk -F= '$1=="Var"{print $2}'
Howdy Other
Or, avoiding the useless use of cat:
$ sed -r 's/[[:alnum:]]+=/\n&/g' file | awk -F= '$1=="Var"{print $2}'
Howdy Other
How it works
sed -r 's/[[:alnum:]]+=/\n&/g'
This places each key,value pair on its own line.
awk -F= '$1=="Var"{print $2}'
This reads the key-value pairs. Since the field separator is chosen to be =, the key ends up as field 1 and the value as field 2. Thus, we just look for lines whose first field is Var and print the corresponding value.
Since discussion in commentary has made it clear that a pure-bash solution would also be acceptable:
#!/bin/bash
case $BASH_VERSION in
''|[0-3].*) echo "ERROR: Bash 4.0 required" >&2; exit 1;;
esac
while read -r -a words; do # iterate over lines of input
declare -A vars=( ) # refresh variables for each line
set -- "${words[#]}" # update positional parameters
for word; do
if [[ $word = *"="* ]]; then # if a word contains an "="...
vars[${word%%=*}]=${word#*=} # ...then set it as an associative-array key
fi
done
echo "${vars[Var]} $5" # Here, we use content read from that line.
done <<<"Version=2 Len=17 Hello Var=Howdy Other"
The <<<"Input Here" could also be <file.txt, in which case lines in the file would be iterated over.
If you wanted to use $Var instead of ${vars[Var]}, then substitute printf -v "${word%%=*}" %s "${word*=}" in place of vars[${word%%=*}]=${word#*=}, and remove references to vars elsewhere. Note that this doesn't allow for a good way to clean up variables between lines of input, as the associative-array approach does.
I will try to explain you a very generic way to do this which you can adapt easily if you want to print out other stuff.
Assume you have a string which has a format like this:
key1=value1 key2=value2 key3=value3
or more generic
key1_fs2_value1_fs1_key2_fs2_value2_fs1_key3_fs2_value3
With fs1 and fs2 two different field separators.
You would like to make a selection or some operations with these values. To do this, the easiest is to store these in an associative array:
array["key1"] => value1
array["key2"] => value2
array["key3"] => value3
array["key1","full"] => "key1=value1"
array["key2","full"] => "key2=value2"
array["key3","full"] => "key3=value3"
This can be done with the following function in awk:
function str2map(str,fs1,fs2,map, n,tmp) {
n=split(str,map,fs1)
for (;n>0;n--) {
split(map[n],tmp,fs2);
map[tmp[1]]=tmp[2]; map[tmp[1],"full"]=map[n]
delete map[n]
}
}
So, after processing the string, you have the full flexibility to do operations in any way you like:
awk '
function str2map(str,fs1,fs2,map, n,tmp) {
n=split(str,map,fs1)
for (;n>0;n--) {
split(map[n],tmp,fs2);
map[tmp[1]]=tmp[2]; map[tmp[1],"full"]=map[n]
delete map[n]
}
}
{ str2map($0," ","=",map) }
{ print map["Var","full"] }
' file
The advantage of this method is that you can easily adapt your code to print any other key you are interested in, or even make selections based on this, example:
(map["Version"] < 3) { print map["var"]/map["Len"] }
The simplest and easiest way is to use the string substitution like this:
property='my.password.is=1234567890=='
name=${property%%=*}
value=${property#*=}
echo "'$name' : '$value'"
The output is:
'my.password.is' : '1234567890=='
Yore.
Using bash's set command, we can split the line into positional parameters like awk.
For each word, we'll try to read a name value pair delimited by =.
When we find a value, assign it to the variable named $key using bash's printf -v feature.
#!/usr/bin/env bash
line='Version=2 Len=17 Hello Var=Howdy Other'
set $line
for word in "$#"; do
IFS='=' read -r key val <<< "$word"
test -n "$val" && printf -v "$key" "$val"
done
echo "$Var $5"
output
Howdy Other
SYNOPSIS
an awk-based solution that doesn't require manually checking the fields to locate the desired key pair :
approach being avoid splitting unnecessary fields or arrays - only performing regex match via function call when needed
only returning FIRST occurrence of input key value. Subsequent matches along the row are NOT returned
i just called it S() cuz it's the closest letter to $
I only included an array (_) of the 3 test values for demo purposes. Those aren't needed. In fact, no state information is being kept at all
caveat being : key-match must be exact - this version of the code isn't for case-insensitive or fuzzy/agile matching
Tested and confirmed working on
- gawk 5.1.1
- mawk 1.3.4
- mawk-2/1.9.9.6
- macos nawk
CODE
# gawk profile, created Fri May 27 02:07:53 2022
{m,n,g}awk '
function S(__,_) {
return \
! match($(_=_<_), "(^|["(_="[:blank:]]")")"(__)"[=][^"(_)"*") \
? "^$" \
: substr(__=substr($-_, RSTART, RLENGTH), index(__,"=")+_^!_)
}
BEGIN { OFS = "\f" # This array is only for testing
_["Version"] _["Len"] _["Var"] # purposes. Feel free to discard at will
} {
for (__ in _) {
print __, S(__) } }'
OUTPUT
Var
Howdy
Len
17
Version
2
So either call the fields in BAU fashion
- $5, $0, $NF, etc
or call S(QUOTED_KEY_VALUE), case-sensitive, like
As a safeguard, to prevent mis-interpreting null strings
or invalid inputs as $0, a non-match returns ^$
instead of empty string
S("Version") to get back 2.
As a bonus, it can safely handle values in multibyte unicode, both for values and even for keys, regardless of whether ur awk is UTF-8-aware or not :
1 ✜
🤡
2 Version
2
3 Var
Howdy
4 Len
17
5 ✜=🤡 Version=2 Len=17 Hello Var=Howdy Other
I know this is particularly regarding awk but mentioning this as many people come here for solutions to break down name = value pairs ( with / without using awk as such).
I found below way simple straight forward and very effective in managing multiple spaces / commas as well -
Source: http://jayconrod.com/posts/35/parsing-keyvalue-pairs-in-bash
change="foo=red bar=green baz=blue"
#use below if var is in CSV (instead of space as delim)
change=`echo $change | tr ',' ' '`
for change in $changes; do
set -- `echo $change | tr '=' ' '`
echo "variable name == $1 and variable value == $2"
#can assign value to a variable like below
eval my_var_$1=$2;
done