extra(3lua): init man pages

man/extra/printfmt.3lua.scd

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+PRINTFMT(3lua) "3lua" "Callisto manual pages"
+
+# NAME
+*printfmt* - write formatted data to standard output
+
+# SYNOPSIS
+*printfmt*(_fstring_: *string*, _..._)
+
+# DESCRIPTION
+*printfmt* writes formatted data
+specified by the format string _fstring_ to standard output,
+behaving similarly to the built in Lua function *string.format*.
+
+It is somewhat equivalent to:
+
+	io.stdout:write(string.format(_fstring_, _..._), '\n')
+
+# EXAMPLES
+Output the values of a list in CSV format:
+
+```
+list = {2, 4, 8, 16}
+printfmt("%d,%d,%d,%d", list[1], list[2], list[3], list[4])
+```
+
+Without using *printfmt* or other string formatting functions,
+this example would require extensive concatenation.
+
+# SEE ALSO
+callisto(3lua), extra(3lua)