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README.md

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+# valid-utf8 — Filter tool to check whether text is valid UTF-8 or not
+
+If no file argument is given, valid-utf8 reads from standard input.
+
+## Build
+
+`make`
+
+after building and installing dependencies:
+
+- [libscstring](https://git.bobpolis.com/bob/libscstring/)
+
+## Install
+
+`sudo make install`
+
+or, on OpenBSD:
+
+`doas gmake install`
+
+## Run
+
+Test a file:
+
+`valid-utf8 <file>`
+
+No output, but exit status will be 0 on success, but 1 if file is not valid
+UTF8.
+
+Use a a filter:
+
+`echo "some text" | valid-utf8`
+
+Again, only exit status will indicate validity.
+
+Find all valid UTF8 files in the current directory, and all directories under
+it:
+
+`find . -exec valid-utf8 "{}" \;`
+