Question

Searched for similar problems and could not find anything that suits my needs exactly:

I have a very large HTML file scraped from multiple websites and I would like to replace all

class="key->from 2nd file"

with

style="xxxx"

At the moment I use sed – it works well but only with small files

while read key; do sed -i “s/class=\”$key\”/style=\”xxxx\”/g”
file_to_process; done < keys

When I’m trying to process something larger it takes ages

Example:

keys - Count: 1233 lines
file_to_ process - Count: 1946 lines

It takes about 40 s to complete only 1/10 of processing I need

real    0m40.901s
user    0m8.181s
sys     0m15.253s

Answer 1

Untested since you didn’t provide any sample input and expected output:

awk '
NR==FNR { keys = keys sep $0; sep = "|"; next }
{ gsub("class=\"(" keys ")\"","style=\"xxxx\"") }
1' keys file_to_process > tmp$$ &&
mv tmp$$ file_to_process