How To Randomly Choose Strings From Same Line In File - linux

Question

I have read this post Select random lines from a file in bash and Random selection of columns using linux command however they don't work specifically with a set of lines that need to stay in the same order. I also searched to find if there was any randomization option using the cut command.
My attempt:
I am trying to replace spaces with new lines, then sort Randomly and then use Head to grab a random string (for each line).
cat file1.txt | while read line; do echo $line | sed 's/ /\n/g' | sort -R | head -1
While this does get the basic job done for one random string, I would like to know if there is a better more efficient way of writing this code? This way, I can add the options to get 1-2 random strings rather than just one.
Here's file1.txt:
#Sample #Example #StackOverflow #Question
#Easy #Simple #Code #Examples #Help
#Support #Really #Helps #Everyone #Learn
Here's my desired output (random values):
#Question
#Code #Examples
#Helps
If you know a better way to implement this code, I would really appreciate your positive input and support.

Answer 1

This is the solution
while read -r line; do echo "$line" | grep -oP '(\S+)' | shuf -n $((RANDOM%2+1)) | paste -s -d' '; done < file1.txt

Answer 2

Using AWK:
%awk 'BEGIN { srand() } { print $(1+int(rand()*NF))}' data.txt
#Question
#Help
#Support
You can modify this to select 2 (or more) random words per line (with duplicates), by repeating the $(rand...) construct, a corresponding number of times (or defining a user function to do this).
Choosing N words from an each line w/o duplicates (by position), is a bit more tricky:
awk '
BEGIN { N=2; srand() }
{
#Collect fields into an array (w)
delete w;
for(i=1;i<=NF;i++) w[i]=$i;
#Randomize Array (Fisher–Yates style)
for(j=NF;j>=2;j--) {
r=1+int(rand()*(j));
if(r!=j) {
x=w[j]; w[j]=w[r]; w[r]=x;
}
}
#Take N first items off the randomized array
for(g=1;g<=(N<NF?N:NF);g++) {
if(g>1) printf " "
printf w[g];
}
printf "\n"
}' data.txt
N - is a (maximum) number of words to pick per line.
To pick a random (at most N) number of items per line, modify the code like that:
awk '
BEGIN { N=2; srand() }
{
#Collect fields into an array (w)
delete w;
for(i=1;i<=NF;i++) w[i]=$i;
#Randomize Array (Fisher–Yates style)
for(j=NF;j>=2;j--) {
r=1+int(rand()*(j));
if(r!=j) {
x=w[j]; w[j]=w[r]; w[r]=x;
}
}
#Take L < N first items off the randomized array
L=1+int(rand()*N);
for(g=1;g<=(L<NF?L:NF);g++) {
if(g>1) printf " "
printf w[g];
}
printf "\n"
}' data.txt
This will print 1 or 2 (N) randomly chosen words per each line.
This code can still be optimized a bit (i.e. by only shuffling first L elements of an array), yet it is 2 or 3 orders of magnitude faster than a shell based solution.

Answer 3

An attempt on bash
cat file1 | xargs -n1 -I# bash -c "output_count=2; \
line=\$(echo \"#\"); \
words=\$(echo \${line} | wc -w); \
for i in \$(eval echo \"{1..\${output_count}}\"); do \
select=\$((1 + RANDOM % \${words})); \
echo \${line} | cut -d \" \" -f \${select} | tr '\n' ' '; \
done;
echo \" \" "
Assumes that the file is called file1.
In order to change the number of randomly selected words, set a different number to output_count
Prints
$ cat file1 | xargs -n1 -I# bash -c "output_count=2; \
line=\$(echo \"#\"); \
words=\$(echo \${line} | wc -w); \
for i in \$(eval echo \"{1..\${output_count}}\"); do \
select=\$((1 + RANDOM % \${words})); \
echo \${line} | cut -d \" \" -f \${select} | tr '\n' ' '; \
done;
echo \" \" "
#Example #Example
#Examples #Help
#Support #Learn
$ cat file1 | xargs -n1 -I# bash -c "output_count=2; \
line=\$(echo \"#\"); \
words=\$(echo \${line} | wc -w); \
for i in \$(eval echo \"{1..\${output_count}}\"); do \
select=\$((1 + RANDOM % \${words})); \
echo \${line} | cut -d \" \" -f \${select} | tr '\n' ' '; \
done;
echo \" \" "
#Question #StackOverflow
#Help #Help
#Everyone #Learn

Answer 4

This might work for you (GNU sed):
sed 'y/ /\n/;s/.*/echo "&"|shuf -n$((RANDOM%2+1))/e;y/\n/ /' file
Replace the spaces in each line by newlines and the using seds substitution eflag, pass each set of lines into the shuf -n command
.