The one link type that is not checked
An outside address. Outside is not in the set, and not in the set is a different claim.
Links between pages as a graph
A page links another page. The link is a name, and a name that has no page is the whole bug of a site build.
What you will see
2. The print is the links of every page.
About 1 min of reading
Try It
Check a link against a set
1
Write the built set
printf '/a/\n/b/\n/c/\n' > /tmp/b.txt; wc -l < /tmp/b.txt
Before you run it, say out loud what it will print. Then open the answer.
What it prints
3. Three pages is the set known at build.
2
Attempt a missing link
printf '/d/\n' | grep -c -f -x /tmp/b.txt /dev/stdin | awk '{print ($1==0) ? "refuse page and link" : "ok"}'
Before you run it, say out loud what it will print. Then open the answer.
What it prints
refuse page and link. Two names is the whole answer.
3
Print the graph
printf 'a -> b\na -> c\n' > /tmp/g.txt; wc -l < /tmp/g.txt
Before you run it, say out loud what it will print. Then open the answer.
What it prints
2. The print is the links of every page.
Data Flow
A page to checked links
1
The links are collected per page
↓
2
Each is checked against the built set
↓
3
A miss refuses with page and link
↓
4
The graph is printed
Why this works
When you have a choice
Why the check is at build rather than at serve
The set is complete at build. Complete at build is why the check costs nothing at serve.
Examples
The link is checked against the built set
The set is known at build. Checking against a known set is checking without a crawl.
A broken link is a refusal
The refusal names the page and the link. Two names is the whole answer.
The graph is printed
The print is the links of every page. A printed graph is a graph that a reader can argue with.
Words this lesson uses
Each one is defined here on this site. Open the entry for the full definition and the other words it points at.
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