Replace a string with a random number for every line, in every file, in a directory in Bash - bash

Question

!/bin/bash
for file in ~/tdg/*.TXT
do
while read p; do
randvalue=`shuf -i 1-99999 -n 1`
sed -i -e "s/55555/${randvalue}/" $file
done < $file
done
This is my script. I'm attempting to replace 55555 with a different random number every time I find it. This currently works, but it replaces every instance of 55555 with the same random number. I have attempted to replace $file at the end of the sed command with $p but that just blows up.
Really though, even if I get to the point were each instance on the same line all of that same random number, but a new random number is used for each line, then I'll be happy.
EDIT
I should have specified this. I would like to actually save the results of the replace in the file, rather than just printing the results to the console.
EDIT
The final working version of my script after JNevill's fantastic help:
!/bin/bash
for file in ~/tdg/*.TXT
do
while read p;
do
gawk '{$0=gensub(/55555/, int(rand()*99999), "g", $0)}1' $file > ${file}.new
done < $file
mv -f ${file}.new $file
done

Answer 1

Since doing this is in sed gets pretty awful and quickly you may want to switch over to awk to perform this:
awk '{$0=gensub(/55555/, int(rand()*99999), "g", $0)}1' $file
Using this, you can remove the inner loop as this will run across the entire file line-by-line as awk does.
You could just swap out the entire script and feed the wildcard filename to awk directly too:
awk '{$0=gensub(/55555/, int(rand()*99999), "g", $0)}1' ~/tdg/*.TXT

Answer 2

This is how to REALLY do what you're trying to do with GNU awk:
awk -i inplace '{ while(sub(/55555/,int(rand()*99999)+1)); print }' ~/tdg/*.TXT
No shell loops or temp files required and it WILL replace every 55555 with a different random number within and across all files.
With other awks it'd be:
seed="$RANDOM"
for file in ~/tdg/*.TXT; do
seed=$(awk -v seed="$seed" '
BEGIN { srand(seed) }
{ while(sub(/55555/,int(rand()*99999)+1)); print > "tmp" }
END { print int(rand()*99999)+1 }
' "$file") &&
mv tmp "$file"
done

Answer 3

A variation on JNevill's solution that generates a different set of random numbers every time you run the script ...
A sample data file:
$ cat grand.dat
abc def 55555
xyz-55555-55555-__+
123-55555-55555-456
987-55555-55555-.2.
.+.-55555-55555-==*
And the script:
$ cat grand.awk
{ $0=gensub(/55555/,int(rand()*seed),"g",$0); print }
gensub(...) : works same as Nevill's answer, while we'll mix up the rand() multiplier by using our seed value [you can throw any numbers in here you wish to help determine size of the resulting value]
** keep in mind that this will replace all occurrences of 55555 on a single line with the same random value
Script in action:
$ awk -f grand.awk seed=${RANDOM} grand.dat
abc def 6939
xyz-8494-8494-__+
123-24685-24685-456
987-4442-4442-.2.
.+.-17088-17088-==*
$ awk -f grand.awk seed=${RANDOM} grand.dat
abc def 4134
xyz-5060-5060-__+
123-14706-14706-456
987-2646-2646-.2.
.+.-10180-10180-==*
$ awk -f grand.awk seed=${RANDOM} grand.dat
abc def 4287
xyz-5248-5248-__+
123-15251-15251-456
987-2744-2744-.2.
.+.-10558-10558-==*
seed=$RANDOM : have the OS generate a random int for us and pass into the awk script as the seed variable