I have one queston about nested loop with bash.
I have an input files with one file name per line (full path)
I read this file and then i make a nest loop:
for i in $filelines ; do
echo $i
for j in $filelines ; do
./program $i $j
done
done
The program I within the loop is pretty low.
Basically it compare the file A with the file B.
I want to skip A vs A comparison (i.e comparing one file with itslef) AND
I want to avoid permutation (i.e. for file A and B, only perform A against B and not B against A).
What is the simplest to perform this?
Version 2: this one takes care of permutations
#!/bin/bash
tmpunsorted="/tmp/compare_unsorted"
tmpsorted="/tmp/compare_sorted"
>$tmpunsorted
while read linei
do
while read linej
do
if [ $linei != $linej ]
then
echo $linei $linej | tr " " "\n" | sort | tr "\n" " " >>$tmpunsorted
echo >>$tmpunsorted
fi
done <filelines
done <filelines
sort $tmpunsorted | uniq > $tmpsorted
while read linecompare
do
echo "./program $linecompare"
done <$tmpsorted
# Cleanup
rm -f $tmpunsorted
rm -f $tmpsorted
What is done here:
I use the while loop to read each line, twice, i and j
if the value of the lines is the same, forget them, no use to consider them
if they are different, output them into a file ($tmpunsorted). And they are sorted in alphebetical order before going tothe $tmpunsorted file. This way the arguments are always in the same order. So a b and b a will be same in the unsorted file.
I then apply sort | uniq on $tmpunsorted, so the result is a list of individual argument pairs.
finally loop on the $tmpsorted file, and call the program on each individual pair.
Since I do not have your program, I did an echo, which you should remove to use the script.
Related
I've got files where the extension is a number:
backup.1
backup.2
backup.3
I now need to check what the highest number is and save this number into a variable. (In the case above it would be i=3)
The problems is actually fairly simple in bash. Bash provides a parameter expansion with substring removal that makes it easy to obtain the final number from the filename. It has the form ${var##*.} which simply searches from the left of the string to the last occurrence of '.' removing all character up to, and including the dot, e.g.
var=backup.1
echo ${var##*.}
1
So all you need to is loop over all files matching backup.[0-9]* and keep a max variable holding the highest number seen, e.g.
max=0
for i in backup.[0-9]*; do
[ "${i##*.}" -gt $max ] && max="${i##*.}"
done
echo "max: $max"
Output based on your files,
max: 3
Look things over and let me know if you have further questions.
highest=$(ls backup* | sort -t"." -k2 -n | tail -n1 | sed -r 's/.*\.(.*)/\1/')
My files:
backup.1
backup.2
backup.3
backup.4
backup.5
backup.6
backup.7
backup.8
backup.9
backup.10
Output:
echo "${highest}"
10
I am trying to write a script which takes a directory containing text files (384 of them) and modifies duplicate lines that have a specific format in order to make them not duplicates.
In particular, I have files in which some lines begin with the '#' character and contain the substring 0:0. A subset of these lines are duplicated one or more times. For those that are duplicated, I'd like to replace 0:0 with i:0 where i starts at 1 and is incremented.
So far I've written a bash script that finds duplicated lines beginning with '#', writes them to a file, then reads them back and uses sed in a while loop to search and replace the first occurrence of the line to be replaced. This is it below:
#!/bin/bash
fdir=$1"*"
#for each fastq file
for f in $fdir
do
(
#find duplicated read names and write to file $f.txt
sort $f | uniq -d | grep ^# > "$f".txt
#loop over each duplicated readname
while read in; do
rname=$in
i=1
#while this readname still exists in the file increment and replace
while grep -q "$rname" $f; do
replace=${rname/0:0/$i:0}
sed -i.bu "0,/$rname/s/$rname/$replace/" "$f"
let "i+=1"
done
done < "$f".txt
rm "$f".txt
rm "$f".bu
done
echo "done" >> progress.txt
)&
background=( $(jobs -p) )
if (( ${#background[#]} ==40)); then
wait -n
fi
done
The problem with it is that its impractically slow. I ran it on a 48 core computer for over 3 days and it hardly got through 30 files. It also seemed to have removed about 10 files and I'm not sure why.
My question is where are the bugs coming from and how can I do this more efficiently? I'm open to using other programming languages or changing my approach.
EDIT
Strangely the loop works fine on one file. Basically I ran
sort $f | uniq -d | grep ^# > "$f".txt
while read in; do
rname=$in
i=1
while grep -q "$rname" $f; do
replace=${rname/0:0/$i:0}
sed -i.bu "0,/$rname/s/$rname/$replace/" "$f"
let "i+=1"
done
done < "$f".txt
To give you an idea of what the files look like below are a few lines from one of them. The thing is that even though it works for the one file, it's slow. Like multiple hours for one file of 7.5 M. I'm wondering if there's a more practical approach.
With regard to the file deletions and other bugs I have no idea what was happening Maybe it was running into memory collisions or something when they were run in parallel?
Sample input:
#D00269:138:HJG2TADXX:2:1101:0:0 1:N:0:CCTAGAAT+ATTCCTCT
GATAAGGACGGCTGGTCCCTGTGGTACTCAGAGTATCGCTTCCCTGAAGA
+
CCCFFFFFHHFHHIIJJJJIIIJJIJIJIJJIIBFHIHIIJJJJJJIJIG
#D00269:138:HJG2TADXX:2:1101:0:0 1:N:0:CCTAGAAT+ATTCCTCT
CAAGTCGAACGGTAACAGGAAGAAGCTTGCTTCTTTGCTGACGAGTGGCG
Sample output:
#D00269:138:HJG2TADXX:2:1101:1:0 1:N:0:CCTAGAAT+ATTCCTCT
GATAAGGACGGCTGGTCCCTGTGGTACTCAGAGTATCGCTTCCCTGAAGA
+
CCCFFFFFHHFHHIIJJJJIIIJJIJIJIJJIIBFHIHIIJJJJJJIJIG
#D00269:138:HJG2TADXX:2:1101:2:0 1:N:0:CCTAGAAT+ATTCCTCT
CAAGTCGAACGGTAACAGGAAGAAGCTTGCTTCTTTGCTGACGAGTGGCG
Here's some code that produces the required output from your sample input.
Again, it is assumed that your input file is sorted by the first value (up to the first space character).
time awk '{
#dbg if (dbg) print "#dbg:prev=" prev
if (/^#/ && prev!=$1) {fixNum=0 ;if (dbg) print "prev!=$1=" prev "!=" $1}
if (/^#/ && (prev==$1 || NR==1) ) {
prev=$1
n=split($1,tmpArr,":") ; n++
#dbg if (dbg) print "tmpArr[6]="tmpArr[6] "\tfixNum="fixNum
fixNum++;tmpArr[6]=fixNum;
# magic to rebuild $1 here
for (i=1;i<n;i++) {
tmpFix ? tmpFix=tmpFix":"tmpArr[i]"" : tmpFix=tmpArr[i]
}
$1=tmpFix ; $0=$0
print $0
}
else { tmpFix=""; print $0 }
}' file > fixedFile
output
#D00269:138:HJG2TADXX:2:1101:1:0 1:N:0:CCTAGAAT+ATTCCTCT
GATAAGGACGGCTGGTCCCTGTGGTACTCAGAGTATCGCTTCCCTGAAGA
+
CCCFFFFFHHFHHIIJJJJIIIJJIJIJIJJIIBFHIHIIJJJJJJIJIG
#D00269:138:HJG2TADXX:2:1101:2:0 1:N:0:CCTAGAAT+ATTCCTCT
CAAGTCGAACGGTAACAGGAAGAAGCTTGCTTCTTTGCTGACGAGTGGCG
I've left a few of the #dbg:... statements in place (but they are now commented out) to show how you can run a small set of data as you have provided, and watch the values of variables change.
Assuming a non-csh, you should be able to copy/paste the code block into a terminal window cmd-line and replace file > fixFile at the end with your real file name and a new name for the fixed file. Recall that awk 'program' file > file (actually, any ...file>file) will truncate the existing file and then try to write, SO you can lose all the data of a file trying to use the same name.
There are probably some syntax improvements that will reduce the size of this code, and there might be 1 or 2 things that could be done that will make the code faster, but this should run very quickly. If not, please post the result of time command that should appear at the end of the run, i.e.
real 0m0.18s
user 0m0.03s
sys 0m0.06s
IHTH
#!/bin/bash
i=4
sort $1 | uniq -d | grep ^# > dups.txt
while read in; do
if [ $((i%4))=0 ] && grep -q "$in" dups.txt; then
x="$in"
x=${x/"0:0 "/$i":0 "}
echo "$x" >> $1"fixed.txt"
else
echo "$in" >> $1"fixed.txt"
fi
let "i+=1"
done < $1
I have a file links.txt:
1 a.sh
3 b.sh
6 c.sh
4 d.sh
So, if i pass 1,4 as parameters to another file(master.sh), a.sh and d.sh should be stored in a variable.
sed '3!d' would print the 3rd line, but not the line that starts with 3. For that, you need sed '/^3 /!d'. The problem is you can't combine them for more lines, as this means "Delete everything that doesn't start with a 3", which means all other lines will be missed. So, use sed -n '/^3 /p' instead, i.e. don't print by default and tell sed what lines to print, not what lines to delete.
You can loop over the argument and create a sed script from them that prints the lines, then run sed using this output:
#!/bin/bash
file=$1
shift
for id in "$#" ; do
echo "/^$id /p"
done | sed -nf- "$file"
Run as script.sh filename 3 4.
If you want to remove the id from the output, you can either use
cut -f2 -d' '
or you can modify the generated sed script to do the work
echo "/^$id /s/.* //p"
i.e. only print if the substitution was successful.
This loops through each argument and greps for it in the links file. The result is piped into cut where we specify the delimiter as a space with -d flag and the field number as 2 with -f flag. Finally this is appended to the array called files.
links="links.txt"
files=()
for arg in $#; do
files=("${files[#]}" `grep "^$arg" "$links" | cut -d" " -f2`)
done;
echo ${files[#]}
Usage:
$ ./master.sh 1 4
a.sh d.sh
Edit:
As pointed out by mklement0, the solution above reads the file once per arg. The following first builds the pattern then reads the file just once.
links="links.txt"
pattern="^$1\s"
for arg in ${#:2}; do
pattern+="|^$arg\s"
done
files=$(grep -E "$pattern" "$links" | cut -d" " -f2)
echo ${files[#]}
Usage:
$ ./master.sh 1 4
a.sh d.sh
Here is another example with grep and cut:
#!/bin/bash
for line in $(grep "$1\|$2" links.txt|cut -d' ' -f2)
do
echo $line
done
Example of usage:
./master.sh 1 4
a.sh
d.sh
Why not just stores the values and call them at will:
items=()
while read -r num file
do
items[num]="$file"
done<links.txt
for arg
do
echo "${items[arg]}"
done
Now you can use the items array any time you like :)
The following awk solution:
preserves the argument order; that is, the results reflect the order in which the lookup values were specified (as opposed to the order in which the lookup values happen to occur in the file).
If that is not important (i.e., if outputting the results in file order is acceptable), the readarray technique below can be combined with this one-liner, which is a generalized variant of Panta's answer:
grep -f <(printf "^%s\n" "$#") links.txt | cut -d' ' -f2-
performs well, because the input file is only read once; the only requirement is that all key-value pairs fit into memory as a whole (as a single associative Awk array (dictionary)).
works with any lookup values that don't have embedded whitespace.
Similarly, the assumption is that the output column values (containing values such as a.sh in the sample input) have no embedded whitespace. awk doesn't handle quoted fields well, so more work would be needed.
#!/bin/bash
readarray -t files < <(
awk -v idList="$*" '
BEGIN { count=split(idList, idArr); for (i in idArr) idDict[idArr[i]]++ }
$1 in idDict { idDict[$1] = $2 }
END { for (i=1; i<=count; ++i) print idDict[idArr[i]] }
' links.txt
)
# Print results.
printf '%s\n' "${files[#]}"
readarray -t files reads stdin input (<) line by line into array variable files.
Note: readarray requires Bash v4+; on Bash 3.x, such as on macOS, replace this part with
IFS=$'\n' read -d '' -ra files
<(...) is a Bash process substitution that, loosely speaking, presents the output from the enclosed command as if it were (self-deleting) temporary file.
This technique allows readarray to run in the current shell (as opposed to a subshell if a pipeline had been used), which is necessary for the files variable to remain defined in the remainder of the script.
The awk command breaks down as follows:
-v idList="$*" passes the space-separated list of all command-line arguments as a single string to Awk variable idList.
Note that this assumes that the arguments have no embedded spaces, which is indeed the case here and also generally the case with identifiers.
BEGIN { ... } is only executed once, before the individual lines are processed:
split(idList, idArr) splits the input ID list into an array by whitespace and stores the result in idArr.
for (i in idArr) idDict[idArr[i]]++ } then converts the (conceptually regular) array into associative array idDict (dictionary), whose keys are the input IDs - this enables efficient lookup by ID later, and also allows storing the lookup result for each ID.
$1 in idDict { idDict[$1] = $2 } is processed for every input line:
Pattern $1 in idDict returns true if the line's first whitespace-separated field ($1) - e.g., 6 - is among the keys (in) of associative array idDict, and, if so, executes the associated action ({...}).
Action { idDict[$1] = $2 } then assigns the second field ($2) - e.g., c.sh - to the iDict entry for key $1.
END { ... } is executed once, after all input lines have been processed:
for (i=1; i<=count; ++i) print idDict[idArr[i]] loops over all input IDs in order and prints each ID's lookup result, which is the value of the dictionary entry with that ID.
I have the following script where I'm parsing 2 csv files to find a MATCH the files have 10000 lines each one. But the processing is taking a long time!!! Is this normal?
My script:
#!/bin/bash
IFS=$'\n'
CSV_FILE1=$1;
CSV_FILE2=$2;
sort -t';' $CSV_FILE1 >> Sorted_CSV1
sort -t';' $CSV_FILE2 >> Sorted_CSV2
echo "PATH1 ; NAME1 ; SIZE1 ; CKSUM1 ; PATH2 ; NAME2 ; SIZE2 ; CKSUM2" >> 'mapping.csv'
while read lineCSV1 #Parse 1st CSV file
do
PATH1=`echo $lineCSV1 | awk '{print $1}'`
NAME1=`echo $lineCSV1 | awk '{print $3}'`
SIZE1=`echo $lineCSV1 | awk '{print $7}'`
CKSUM1=`echo $lineCSV1 | awk '{print $9}'`
while read lineCSV2 #Parse 2nd CSV file
do
PATH2=`echo $lineCSV2 | awk '{print $1}'`
NAME2=`echo $lineCSV2 | awk '{print $3}'`
SIZE2=`echo $lineCSV2 | awk '{print $7}'`
CKSUM2=`echo $lineCSV2 | awk '{print $9}'`
# Test if NAM1 MATCHS NAME2
if [[ $NAME1 == $NAME2 ]]; then
#Test checksum OF THE MATCHING NAME
if [[ $CKSUM1 != $CKSUM2 ]]; then
#MAPPING OF THE MATCHING LINES
echo $PATH1 ';' $NAME1 ';' $SIZE1 ';' $CKSUM1 ';' $PATH2 ';' $NAME2 ';' $SIZE2 ';' $CKSUM2 >> 'mapping.csv'
fi
break #When its a match break the while loop and go the the next Row of the 1st CSV File
fi
done < Sorted_CSV2 #Done CSV2
done < Sorted_CSV1 #Done CSV1
This is a quadratic order. Also, see Tom Fenech comment: You are calling awk several times inside a loop inside another loop. Instead of using awk for the fields in every line try setting the IFS shell variable to ";" and read the fields directly in read commands:
IFS=";"
while read FIELD11 FIELD12 FIELD13; do
while read FIELD21 FIELD22 FIELD23; do
...
done <Sorted_CSV2
done <Sorted_CSV1
Though, this would be still O(N^2) and very inefficient. It seems you are matching 2 fields by a coincident field. This task is easier and faster to accomplish by using join command line utility, and would reduce order from O(N^2) to O(N).
Whenever you say "Does this file/data list/table have something that matches this file/data list/table?", you should think of associative arrays (sometimes called hashes).
An associative array is keyed by a particular value and each key is associated with a value. The nice thing is that finding a key is extremely fast.
In your loop of a loop, you have 10,000 lines in each file. You're outer loop executed 10,000 times. Your inner loop may execute 10,000 times for each and every line in your first file. That's 10,000 x 10,000 times you go through that inner loop. That's potentially looping 100 million times through that inner loop. Think you can see why your program might be a little slow?
In this day and age, having a 10,000 member associative array isn't that bad. (Imagine doing this back in 1980 on a MS-DOS system with 256K. It just wouldn't work). So, let's go through the first file, create a 10,000 member associative array, and then go through the second file looking for matching lines.
Bash 4.x has associative arrays, but I only have Bash 3.2 on my system, so I can't really give you an answer in Bash.
Besides, sometimes Bash isn't the answer to a particular issue. Bash can be a bit slow and the syntax can be error prone. Awk might be faster, but many versions don't have associative arrays. This is really a job for a higher level scripting language like Python or Perl.
Since I can't do a Bash answer, here's a Perl answer. Maybe this will help. Or, maybe this will inspire someone who has Bash 4.x can give an answer in Bash.
I Basically open the first file and create an associative array keyed by the checksum. If this is a sha1 checksum, it should be unique for all files (unless they're an exact match). If you don't have a sha1 checksum, you'll need to massage the structure a wee bit, but it's pretty much the same idea.
Once I have the associative array figured out, I then open file #2 and simply see if the checksum already exists in the file. If it does, I know I have a matching line, and print out the two matches.
I have to loop 10,000 times in the first file, and 10,000 times in the second. That's only 20,000 loops instead of 10 million that's 20,000 times less looping which means the program will run 20,000 times faster. So, if it takes 2 full days for your program to run with a double loop, an associative array solution will work in less than one second.
#! /usr/bin/env perl
#
use strict;
use warnings;
use autodie;
use feature qw(say);
use constant {
FILE1 => "file1.txt",
FILE2 => "file2.txt",
MATCHING => "csv_matches.txt",
};
#
# Open the first file and create the associative array
#
my %file_data;
open my $fh1, "<", FILE1;
while ( my $line = <$fh1> ) {
chomp $line;
my ( $path, $blah, $name, $bather, $yadda, $tl_dr, $size, $etc, $check_sum ) = split /\s+/, $line;
#
# The main key is "check_sum" which **should** be unique, especially if it's a sha1
#
$file_data{$check_sum}->{PATH} = $path;
$file_data{$check_sum}->{NAME} = $name;
$file_data{$check_sum}->{SIZE} = $size;
}
close $fh1;
#
# Now, we have the associative array keyed by the data we want to match, read file 2
#
open my $fh2, "<", FILE2;
open my $csv_fh, ">", MATCHING;
while ( my $line = <$fh2> ) {
chomp $line;
my ( $path, $blah, $name, $bather, $yadda, $tl_dr, $size, $etc, $check_sum ) = split /\s+/, $line;
#
# If there is a matching checksum in file1, we know we have a matching entry
#
if ( exists $file_data{$check_sum} ) {
printf {$csv_fh} "%s;%s:%s:%s:%s:%s\n",
$file_data{$check_sum}->{PATH}, $file_data{$check_sum}->{NAME}, $file_data{$check_sum}->{SIZE},
$path, $name, $size;
}
}
close $fh2;
close $csv_fh;
BUGS
(A good manpage always list issues!)
This assumes one match per file. If you have multiple duplicates in file1 or file2, you will only pick up the last one.
This assumes a sha256 or equivalent checksum. In such a checksum, it is extremely unlikely that two files will have the same checksum unless they match. A 16bit checksum from the historic sum command may have collisions.
Although a proper database engine would make a much better tool for this, it is still very well possible to do it with awk.
The trick is to sort your data, so that records with the same name are grouped together. Then a single pass from top to bottom is enough to find the matches. This can be done in linear time.
In detail:
Insert two columns in both CSV files
Make sure every line starts with the name. Also add a number (either 1 or 2) which denotes from which file the line originates. We will need this when we merge the two files together.
awk -F';' '{ print $2 ";1;" $0 }' csvfile1 > tmpfile1
awk -F';' '{ print $2 ";2;" $0 }' csvfile2 > tmpfile2
Concatenate the files, then sort the lines
sort tmpfile1 tmpfile2 > tmpfile3
Scan the result, report the mismatches
awk -F';' -f scan.awk tmpfile3
Where scan.awk contains:
BEGIN {
origin = 3;
}
$1 == name && $2 > origin && $6 != checksum {
print record;
}
{
name = $1;
origin = $2;
checksum = $6;
sub(/^[^;]*;.;/, "");
record = $0;
}
Putting it all together
Crammed together into a Bash oneliner, without explicit temporary files:
(awk -F';' '{print $2";1;"$0}' csvfile1 ; awk -F';' '{print $2";2;"$0}' csvfile2) | sort | awk -F';' 'BEGIN{origin=3}$1==name&&$2>origin&&$6!=checksum{print record}{name=$1;origin=$2;checksum=$6;sub(/^[^;]*;.;/,"");record=$0;}'
Notes:
If the same name appears more than once in csvfile1, then all but the last one are ignored.
If the same name appears more than once in csvfile2, then all but the first one are ignored.
I am trying to write a program that will print out every line from a file with another line of that file added at the end, basically creating pairs from a portion of each line. If the line is the same, it will do nothing. Also, it must avoid repeating the same pairs. A B is the same as B A
In short
FileInput:
otherstuff A
otherstuff B
otherstuff C
otherstuff D
Output:
A B
A C
A D
B C
B D
C D
I was trying to do this with a BASH script, but was having trouble because I could not get my nested while loops to work. It would read the first line, compare it to each other line, and then stop (Basically only outputting the first 3 lines in the example output above, the outer while loop only ran once).
I also suspect I might be able to do this using MATLAB, so suggestions using that are also welcome.
Here is the bash script that I have thus far. As I said, it is no printing out correctly for me, as the outer loop only runs once.
#READS IN file from terminal
FILE1=$1
#START count at 0
count0=
exec 3<&0
exec 0< $FILE1
while read LINEa; do
while read LINEb; do
eventIDa=$(echo $LINEa | cut -c20-23)
eventIDb=$(echo $LINEb | cut -c20-23)
echo $eventIDa $eventIDb
done
done
Using bash:
#!/bin/bash
[ -f "$1" ] || { echo >&2 "File not found"; exit 1; }
mapfile -t lines < <(cut -c20-23 <"$1" | sort | uniq)
for i in ${!lines[#]}; do
elem1=${lines[$i]}
unset lines[$i]
for elem2 in "${lines[#]}"; do
echo "$elem1" "$elem2"
done
done
This will read a file given as a parameter on the command line, sort and filter out duplicates, and output all combinations. You can modify the parameter to cut to adjust to your particular input file.
Due to the particular way you seem to indent to use cut, your input example above won't work. Instead, use something with the correct line length, such as:
123456789012345678 A
123456789012345678 B
123456789012345678 C
123456789012345678 D
Assuming the otherstuff is not relevant (otherwise you can of course add it later) this should do the trick in Matlab:
combnk({'A' 'B' 'C' 'D'},2)