Add Check What Is Inside A Zip File as a Unix TIL

README.md

@@ -10,7 +10,7 @@ working across different projects via [VisualMode](https://www.visualmode.dev/).
 
 For a steady stream of TILs, [sign up for my newsletter](https://visualmode.kit.com/newsletter).
 
-_1870 TILs and counting..._
+_1871 TILs and counting..._
 
 See some of the other learning resources I work on:
 
@@ -1753,6 +1753,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Check SSH Key Fingerprints Of Known Hosts](unix/check-ssh-key-fingerprints-of-known-hosts.md)
 - [Check The Current Working Directory](unix/check-the-current-working-directory.md)
 - [Check The Installed OpenSSL Version](unix/check-the-installed-openssl-version.md)
+- [Check What Is Inside A Zip File](unix/check-what-is-inside-a-zip-file.md)
 - [Clear The Screen](unix/clear-the-screen.md)
 - [Combine All My TILs Into A Single File](unix/combine-all-my-tils-into-a-single-file.md)
 - [Command Line Length Limitations](unix/command-line-length-limitations.md)

unix/check-what-is-inside-a-zip-file.md

@@ -0,0 +1,31 @@
+# Check What Is Inside A Zip File
+
+Before unzipping a file, it can be useful to check the contents. You can learn a
+few things from doing this. First off, are all the files nested under some extra
+top-level directory? How many files are in there? How big are certain files? Etc.
+
+The `-l` flag to `unzip` can help answer these questions.
+
+```bash
+❯ unzip -l zipped-files.zip
+Archive:  zipped-files.zip
+  Length      Date    Time    Name
+---------  ---------- -----   ----
+        0  08-22-2026 08:54   files-to-zip/
+       14  08-22-2026 08:54   files-to-zip/data.json
+       38  08-22-2026 08:53   files-to-zip/notes.md
+       14  08-22-2026 08:53   files-to-zip/hello.txt
+---------                     -------
+       66                     4 files
+```
+
+Notice that the first line is for `files-to-zip/` which tells us that everything
+is nested under the top-level directory that was probably the target of the
+`zip` command. Everything is organized into a table with labeled columns which
+allows us to answer our questions and get a good idea of what is in there.
+
+In my experience, zip files tend to have dozens to hundreds of files, so it is
+even better to pipe the above to a pager like `less`. That way you can search
+and navigate through everything that's in there.
+
+See `man unzip` for more details.