I am trying to make a list of URLs of webpages, based on whether the webpages contain the text "XYZ".

The URLs are of the form:


??? is a number starting with 1, incremented by 1 each time, until an error page is encountered (say a page containing the text "ERROR”)

I want to dump the URLs of the positive matches into an output file. I read curl can sequentially scan such URLs, and its output can be passed to grep. However, I am unsure how I can retrieve and save the URL, after the grep output.

closed as unclear what you're asking by G-Man, RalfFriedl, Anthony Geoghegan, Jeff Schaller, JigglyNaga Dec 10 '18 at 10:12

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 3
    I feel like you're asking "If I'm at a known location and drive following given directions, how do I know where I am?" If you ran curl, how do you not know the URL? – G-Man Dec 8 '18 at 3:54
  • I do know the URL, but how do I output it after grepping on the curl output (webpage content)? – halfbytecode Dec 8 '18 at 4:00
  • 2
    I still don't understand the question.  Given a string, do you know how to output it?  (Hint: echo or printf.) – G-Man Dec 8 '18 at 4:27
  • Fetch webpages using curl, determine if the webpages (not URLs) contain the required text, output the URLs of positive matches. – halfbytecode Dec 8 '18 at 4:35
  • Rather than adding information in the comments, you should edit the question to improve its quality (see How to Ask). All relevant details should be in the question itself – not in the comments. – Anthony Geoghegan Dec 8 '18 at 19:49

It might be easier to generate the URLs without curl:

for ((i=1; i<1000; i++)); do
    if curl -s "$url" | grep -q XYZ; then
        echo "$url" >> positive-matches.txt
  • Thank you. I started working on a script, and your answer helped me. – halfbytecode Dec 8 '18 at 11:27
  • 2
    @halfbytecode I've upvoted this answer but I'd suggest that you also accept it (click on the check mark) to show your appreciation as it answers your question and you don't yet have the ability to upvote answers. – Anthony Geoghegan Dec 8 '18 at 19:43

I have made a working script. Sharing it in case someone finds it helpful. @nohillside 's answer helped me.



while true

    text=`curl -s "$url"`

    if echo "$text" | grep -q "ERROR"
    elif echo "$text" | grep -q "XYZ"
        echo "$url" >> matches.txt



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