Bash script that reads from files has garbled output - bash

I am very new to Bash scripting. I am trying to write a script that works with two files. Each line of the files looks like this:
INST <_variablename_> = <_value_>;
The two files share many variables, but they are in a different order, so I can't just diff them. What I want to do is go through the files and find all the variables that have different values, or all the variables that are specified in one file but not the other.
Here is my script so far. Again, I'm very new to Bash so please go easy on me, but also feel free to suggest improvements (I appreciate it).
#!/bin/bash
line_no=1
while read LINE
do
search_var=`echo $LINE | awk '{print $2}'`
result_line=`grep -w $search_var file2`
if [ $? -eq 1 ]
then
echo "$line_no: not found [ $search_var ]"
else
value=`echo $LINE | awk '{print $4}'`
result_value=`echo $result_line | awk '{print $4}'`
if [ "$value" != "$result_value" ]
then
echo "$line_no: mismatch [ $search_var , $value , $result_value ]"
fi
fi
line_no=`expr $line_no + 1`
done < file1
Now here's an example of some of the output that I'm getting:
111: mismatch [ TXAREFBIASSEL , TRUE; , "TRUE"; ]
, 4'b1100; ] [ TXTERMTRIM , 4'b1100;
113: not found [ VREFBIASMODE ]
, 2'b00; ]ch [ CYCLE_LIMIT_SEL , 2'b00;
, 3'b100; ]h [ FDET_LCK_CAL , 3'b101;
The first line is what I would expect (I'll deal with the quotes later). On the second, fourth, and fifth line, it looks like the final value is overwriting the "line_no: mismatch" part. And furthermore, on the second and fourth line, the values DO match--it shouldn't print anything at all!
I asked my friend about this, and his suggestion was "Do it in Perl." So I'm learning Perl right now, but I'd still like to know what's going on and why this is happening.
Thank you!
EDIT:
Sigh. I figured out the problem. One of the files had Unix line breaks, and the other had DOS line breaks. I actually thought this might be the case, but I also thought that vi was supposed to display some character if it opened a dos-ended file. Since they looked the same, I assumed that they were the same.
Thanks for your help and suggestions everybody!

Rather than simply replacing the Bash language with Perl, how about a paradigm shift?
diff -w <(sort file1) <(sort file2)
This will sort both files, so that the variables will appear in the same order in each, and will diff the results (ignoring whitespace differences, just for fun).
This may give you more or less what you need, without any "code" per se. Note that you could also sort the files into intermediate files and run diff on those if you find that easier...I happen to like doing it with no temporary files.

What about this? 2 is avaliable in both files and same value. other values can be parsed easily.
sort 1.txt 2.txt | uniq -c
2 a = 10
1 b = 20
1 b = 40
1 c = 10
1 c = 30
1 e = 50
or like this get your key and values.
sed 's|INST \(.*\) = \(.*\)|\1 = \2|' 1.txt 2.txt | sort | uniq -c
2 a = 10
1 b = 20
1 b = 40
1 c = 10
1 c = 30
1 e = 50

Related

Make cat command to operate recursively looping through a directory

I have a large directory of data files which I am in the process of manipulating to get them in a desired format. They each begin and end 15 lines too soon, meaning I need to strip the first 15 lines off one file and paste them to the end of the previous file in the sequence.
To begin, I have written the following code to separate the relevant data into easy chunks:
#!/bin/bash
destination='media/user/directory/'
for file1 in `ls $destination*.ascii`
do
echo $file1
file2="${file1}.end"
file3="${file1}.snip"
sed -e '16,$d' $file1 > $file2
sed -e '1,15d' $file1 > $file3
done
This worked perfectly, so the next step is the worlds simplest cat command:
cat $file3 $file2 > outfile
However, what I need to do is to stitch file2 to the previous file3. Look at this screenshot of the directory for better understanding.
See how these files are all sequential over time:
*_20090412T235945_20090413T235944_* ### April 13
*_20090413T235945_20090414T235944_* ### April 14
So I need to take the 15 lines snipped off the April 14 example above and paste it to the end of the April 13 example.
This doesn't have to be part of the original code, in fact it would be probably best if it weren't. I was just hoping someone would be able to help me get this going.
Thanks in advance! If there is anything I have been unclear about and needs further explanation please let me know.
"I need to strip the first 15 lines off one file and paste them to the end of the previous file in the sequence."
If I understand what you want correctly, it can be done with one line of code:
awk 'NR==1 || FNR==16{close(f); f=FILENAME ".new"} {print>f}' file1 file2 file3
When this has run, the files file1.new, file2.new, and file3.new will be in the new form with the lines transferred. Of course, you are not limited to three files: you may specify as many as you like on the command line.
Example
To keep our example short, let's just strip the first 2 lines instead of 15. Consider these test files:
$ cat file1
1
2
3
$ cat file2
4
5
6
7
8
$ cat file3
9
10
11
12
13
14
15
Here is the result of running our command:
$ awk 'NR==1 || FNR==3{close(f); f=FILENAME ".new"} {print>f}' file1 file2 file3
$ cat file1.new
1
2
3
4
5
$ cat file2.new
6
7
8
9
10
$ cat file3.new
11
12
13
14
15
As you can see, the first two lines of each file have been transferred to the preceding file.
How it works
awk implicitly reads each file line-by-line. The job of our code is to choose which new file a line should be written to based on its line number. The variable f will contain the name of the file that we are writing to.
NR==1 || FNR==16{f=FILENAME ".new"}
When we are reading the first line of the first file, NR==1, or when we are reading the 16th line of whatever file we are on, FNR==16, we update f to be the name of the current file with .new added to the end.
For the short example, which transferred 2 lines instead of 15, we used the same code but with FNR==16 replaced with FNR==3.
print>f
This prints the current line to file f.
(If this was a shell script, we would use >>. This is not a shell script. This is awk.)
Using a glob to specify the file names
destination='media/user/directory/'
awk 'NR==1 || FNR==16{close(f); f=FILENAME ".new"} {print>f}' "$destination"*.ascii
Your task is not that difficult at all. You want to gather a list of all _end files in the directory (using a for loop and globbing, NOT looping on the results of ls). Once you have all the end files, you simply parse the dates using parameter expansion w/substing removal say into d1 and d2 for date1 and date2 in:
stuff_20090413T235945_20090414T235944_end
| d1 | | d2 |
then you simply subtract 1 from d1 into say date0 or d0 and then construct a previous filename out of d0 and d1 using _snip instead of _end. Then just test for the existence of the previous _snip filename, and if it exists, paste your info from the current _end file to the previous _snip file. e.g.
#!/bin/bash
for i in *end; do ## find all _end files
d1="${i#*stuff_}" ## isolate first date in filename
d1="${d1%%T*}"
d2="${i%T*}" ## isolate second date
d2="${d2##*_}"
d0=$((d1 - 1)) ## subtract 1 from first, get snip d1
prev="${i/$d1/$d0}" ## create previous 'snip' filename
prev="${prev/$d2/$d1}"
prev="${prev%end}snip"
if [ -f "$prev" ] ## test that prev snip file exists
then
printf "paste to : %s\n" "$prev"
printf " from : %s\n\n" "$i"
fi
done
Test Input Files
$ ls -1
stuff_20090413T235945_20090414T235944_end
stuff_20090413T235945_20090414T235944_snip
stuff_20090414T235945_20090415T235944_end
stuff_20090414T235945_20090415T235944_snip
stuff_20090415T235945_20090416T235944_end
stuff_20090415T235945_20090416T235944_snip
stuff_20090416T235945_20090417T235944_end
stuff_20090416T235945_20090417T235944_snip
stuff_20090417T235945_20090418T235944_end
stuff_20090417T235945_20090418T235944_snip
stuff_20090418T235945_20090419T235944_end
stuff_20090418T235945_20090419T235944_snip
Example Use/Output
$ bash endsnip.sh
paste to : stuff_20090413T235945_20090414T235944_snip
from : stuff_20090414T235945_20090415T235944_end
paste to : stuff_20090414T235945_20090415T235944_snip
from : stuff_20090415T235945_20090416T235944_end
paste to : stuff_20090415T235945_20090416T235944_snip
from : stuff_20090416T235945_20090417T235944_end
paste to : stuff_20090416T235945_20090417T235944_snip
from : stuff_20090417T235945_20090418T235944_end
paste to : stuff_20090417T235945_20090418T235944_snip
from : stuff_20090418T235945_20090419T235944_end
(of course replace stuff_ with your actual prefix)
Let me know if you have questions.
You could store the previous $file3 value in a variable (and do a check if it is not the first run with -z check):
#!/bin/bash
destination='media/user/directory/'
prev=""
for file1 in $destination*.ascii
do
echo $file1
file2="${file1}.end"
file3="${file1}.snip"
sed -e '16,$d' $file1 > $file2
sed -e '1,15d' $file1 > $file3
if [ -z "$prev" ]; then
cat $prev $file2 > outfile
fi
prev=$file3
done

Sorting on multiple columns w/ an output file per key

I'm uncertain as to how I can use the until loop inside a while loop.
I have an input file of 500,000 lines that look like this:
9 1 1 0.6132E+02
9 2 1 0.6314E+02
10 3 1 0.5874E+02
10 4 1 0.5266E+02
10 5 1 0.5571E+02
1 6 1 0.5004E+02
1 7 1 0.5450E+02
2 8 1 0.5696E+02
11 9 1 0.6369E+02
.....
And what I'm hoping to achieve is to sort the numbers in the first column in numerical order such that I can pull all the similar lines (eg. lines that start with the same number) into new text files "cluster${i}.txt". From there I want to sort the fourth column of ("cluster${i}.txt") files in numerical order. After sorting I would like to write the first row of each sorted "cluster${i}.txt" file into a single output file. A sample output of "cluster1.txt" would like this:
1 6 1 0.5004E+02
1 7 1 0.5450E+02
1 11 1 0.6777E+02
....
as well as an output.txt file that would look like this:
1 6 1 0.5004E+02
2 487 1 0.3495E+02
3 34 1 0.0344E+02
....
Here is what I've written:
#!/bin/bash
input='input.txt'
i=1
sort -nk 1 $input > 'temp.txt'
while read line; do
awk -v var="$i" '$1 == var' temp.txt > "cluster${i}.txt"
until [[$i -lt 20]]; do
i=$((i+1))
done
done
for f in *.txt; do
sort -nk 4 > temp2.txt
head -1 temp2.txt
rm temp2.txt
done > output.txt
This only takes one line, if your sort -n knows how to handle exponential notation:
sort -nk 1,4 <in.txt | awk '{ of="cluster" $1 ".txt"; print $0 >>of }'
...or, to also write the first line for each index to output.txt:
sort -nk 1,4 <in.txt | awk '
{
if($1 != last) {
print $0 >"output.txt"
last=$1
}
of="cluster" $1 ".txt";
print $0 >of
}'
Consider using an awk implementation -- such as GNU awk -- which will cache file descriptors, rather than reopening each output file for every append; this will greatly improve performance.
By the way, let's look at what was wrong with the original script:
It was slow. Really, really slow.
Starting a new instance of awk 20 times for every line of input (because the whole point of while read is to iterate over individual lines, so putting an awk inside a while read is going to run awk at least once per line) is going to have a very appreciable impact on performance. Not that it was actually doing this, because...
The while read line outer loop was reading from stdin, not temp.txt or input.txt.
Thus, the script was hanging if stdin didn't have anything written on it, or wasn't executing the contents of the loop at all if stdin pointed to a source with no content like /dev/null.
The inner loop wasn't actually processing the line read by the outer loop. line was being read, but all of temp.txt was being operated on.
The awk wasn't actually inside the inner loop, but rather was inside the outer loop, just before the inner loop. Consequently, it wasn't being run 20 times with different values for i, but run only once per line read, with whichever value for i was left over from previously executed code.
Whitespace is important to how commands are parsed. [[foo]] is wrong; it needs to be [[ foo ]].
To "fix" the inner loop, to do what I imagine you meant to write, might look like this:
# this is slow and awful, but at least it'll work.
while IFS= read -r line; do
i=0
until [[ $i -ge 20 ]]; do
awk -v var="$i" '$1 == var' <<<"$line" >>"cluster${i}.txt"
i=$((i+1))
done
done <temp.txt
...or, somewhat better (but still not as good as the solution suggested at the top):
# this is a somewhat less awful.
for (( i=0; i<=20; i++ )); do
awk -v var="$i" '$1 == var' <temp.txt >"cluster${i}.txt"
head -n 1 "cluster${i}.txt"
done >output.txt
Note how the redirection to output.txt is done just once, for the whole loop -- this means we're only opening the file once.

Join in unix when field is numeric in a huge file

So I have two files. File A and File B. File A is huge (>60 GB) and has 16 rows, a mix of numeric and strings, is separated by "|", and has over 600,000,000 lines. Field 3 in this file is the ID and it is a numeric field, with different lengths (e.g., someone's ID can be 1, and someone else's can be 100)
File B just has a bunch of ID (~1,000,000) and I want to extract all the rows from File A that have an ID that is in `File B'. I have started doing this using Linux with the following code
sort -k3,3 -t'|' FileA.txt > FileASorted.txt
sort -k1,1 -t'|' FileB.txt > FileBSorted.txt
join -1 3 -2 1 -t'|' FileASorted.txt FileBSorted.txt > merged.txt
The problem I have is that merged.txt is empty (when I know for a fact there are at least 10 matches)... I have googled this and it seems like the issue is that the join field (the ID) is numeric. Some people propose padding the field with zeros but 1) I'm not entirely sure how to do this, and 2) this seems very slow/time inefficient.
Any other ideas out there? or help on how to add the padding of 0s only to the relevant field.
I would first sort file b using the unique flag (-u)
sort -u file.b > sortedfile.b
Then loop through sortedfile.b and for each grep file.a. In zsh I would do a
foreach C (`cat sortedfile.b`)
grep $C file.a > /dev/null
if [ $? -eq 0 ]; then
echo $C >> res.txt
fi
end
Redirect output from grep to /dev/null and test whether there was a match ($? -eq 0) and append (>>) the result from that line to res.txt.
A single > will overwrite the file. I'm a bit rusty at zsh now so there might be a typo. You may be using bash which can have a slightly different foreach syntax.

Using awk with Operations on Variables

I'm trying to write a Bash script that reads files with several columns of data and multiplies each value in the second column by each value in the third column, adding the results of all those multiplications together.
For example if the file looked like this:
Column 1 Column 2 Column 3 Column 4
genome 1 30 500
genome 2 27 500
genome 3 83 500
...
The script should multiply 1*30 to give 30, then 2*27 to give 54 (and add that to 30), then 3*83 to give 249 (and add that to 84) etc..
I've been trying to use awk to parse the input file but am unsure of how to get the operation to proceed line by line. Right now it stops after the first line is read and the operations on the variables are performed.
Here's what I've written so far:
for file in fileone filetwo
do
set -- $(awk '/genome/ {print $2,$3}' $file.hist)
var1=$1
var2=$2
var3=$((var1*var2))
total=$((total+var3))
echo var1 \= $var1
echo var2 \= $var2
echo var3 \= $var3
echo total \= $total
done
I tried placing a "while read" loop around everything but could not get the variables to update with each line. I think I'm going about this the wrong way!
I'm very new to Linux and Bash scripting so any help would be greatly appreciated!
That's because awk reads the entire file and runs its program on each line. So the output you get from awk '/genome/ {print $2,$3}' $file.hist will look like
1 30
2 27
3 83
and so on, which means in the bash script, the set command makes the following variable assignments:
$1 = 1
$2 = 30
$3 = 2
$4 = 27
$5 = 3
$6 = 83
etc. But you only use $1 and $2 in your script, meaning that the rest of the file's contents - everything after the first line - is discarded.
Honestly, unless you're doing this just to learn how to use bash, I'd say just do it in awk. Since awk automatically runs over every line in the file, it'll be easy to multiply columns 2 and 3 and keep a running total.
awk '{ total += $2 * $3 } ENDFILE { print total; total = 0 }' fileone filetwo
Here ENDFILE is a special address that means "run this next block at the end of each file, not at each line."
If you are doing this for educational purposes, let me say this: the only thing you need to know about doing arithmetic in bash is that you should never do arithmetic in bash :-P Seriously though, when you want to manipulate numbers, bash is one of the least well-adapted tools for that job. But if you really want to know, I can edit this to include some information on how you could do this task primarily in bash.
I agree that awk is in general better suited for this kind of work, but if you are curious what a pure bash implementation would look like:
for f in file1 file2; do
total=0
while read -r _ x y _; do
((total += x * y))
done < "$f"
echo "$total"
done

What's an easy way to read random line from a file?

What's an easy way to read random line from a file in a shell script?
You can use shuf:
shuf -n 1 $FILE
There is also a utility called rl. In Debian it's in the randomize-lines package that does exactly what you want, though not available in all distros. On its home page it actually recommends the use of shuf instead (which didn't exist when it was created, I believe). shuf is part of the GNU coreutils, rl is not.
rl -c 1 $FILE
Another alternative:
head -$((${RANDOM} % `wc -l < file` + 1)) file | tail -1
sort --random-sort $FILE | head -n 1
(I like the shuf approach above even better though - I didn't even know that existed and I would have never found that tool on my own)
This is simple.
cat file.txt | shuf -n 1
Granted this is just a tad slower than the "shuf -n 1 file.txt" on its own.
perlfaq5: How do I select a random line from a file? Here's a reservoir-sampling algorithm from the Camel Book:
perl -e 'srand; rand($.) < 1 && ($line = $_) while <>; print $line;' file
This has a significant advantage in space over reading the whole file in. You can find a proof of this method in The Art of Computer Programming, Volume 2, Section 3.4.2, by Donald E. Knuth.
using a bash script:
#!/bin/bash
# replace with file to read
FILE=tmp.txt
# count number of lines
NUM=$(wc - l < ${FILE})
# generate random number in range 0-NUM
let X=${RANDOM} % ${NUM} + 1
# extract X-th line
sed -n ${X}p ${FILE}
Single bash line:
sed -n $((1+$RANDOM%`wc -l test.txt | cut -f 1 -d ' '`))p test.txt
Slight problem: duplicate filename.
Here's a simple Python script that will do the job:
import random, sys
lines = open(sys.argv[1]).readlines()
print(lines[random.randrange(len(lines))])
Usage:
python randline.py file_to_get_random_line_from
Another way using 'awk'
awk NR==$((${RANDOM} % `wc -l < file.name` + 1)) file.name
A solution that also works on MacOSX, and should also works on Linux(?):
N=5
awk 'NR==FNR {lineN[$1]; next}(FNR in lineN)' <(jot -r $N 1 $(wc -l < $file)) $file
Where:
N is the number of random lines you want
NR==FNR {lineN[$1]; next}(FNR in lineN) file1 file2
--> save line numbers written in file1 and then print corresponding line in file2
jot -r $N 1 $(wc -l < $file) --> draw N numbers randomly (-r) in range (1, number_of_line_in_file) with jot. The process substitution <() will make it look like a file for the interpreter, so file1 in previous example.
#!/bin/bash
IFS=$'\n' wordsArray=($(<$1))
numWords=${#wordsArray[#]}
sizeOfNumWords=${#numWords}
while [ True ]
do
for ((i=0; i<$sizeOfNumWords; i++))
do
let ranNumArray[$i]=$(( ( $RANDOM % 10 ) + 1 ))-1
ranNumStr="$ranNumStr${ranNumArray[$i]}"
done
if [ $ranNumStr -le $numWords ]
then
break
fi
ranNumStr=""
done
noLeadZeroStr=$((10#$ranNumStr))
echo ${wordsArray[$noLeadZeroStr]}
Here is what I discovery since my Mac OS doesn't use all the easy answers. I used the jot command to generate a number since the $RANDOM variable solutions seems not to be very random in my test. When testing my solution I had a wide variance in the solutions provided in the output.
RANDOM1=`jot -r 1 1 235886`
#range of jot ( 1 235886 ) found from earlier wc -w /usr/share/dict/web2
echo $RANDOM1
head -n $RANDOM1 /usr/share/dict/web2 | tail -n 1
The echo of the variable is to get a visual of the generated random number.
Using only vanilla sed and awk, and without using $RANDOM, a simple, space-efficient and reasonably fast "one-liner" for selecting a single line pseudo-randomly from a file named FILENAME is as follows:
sed -n $(awk 'END {srand(); r=rand()*NR; if (r<NR) {sub(/\..*/,"",r); r++;}; print r}' FILENAME)p FILENAME
(This works even if FILENAME is empty, in which case no line is emitted.)
One possible advantage of this approach is that it only calls rand() once.
As pointed out by #AdamKatz in the comments, another possibility would be to call rand() for each line:
awk 'rand() * NR < 1 { line = $0 } END { print line }' FILENAME
(A simple proof of correctness can be given based on induction.)
Caveat about rand()
"In most awk implementations, including gawk, rand() starts generating numbers from the same starting number, or seed, each time you run awk."
-- https://www.gnu.org/software/gawk/manual/html_node/Numeric-Functions.html

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