Docs: add proper date to man page

Makefile

@@ -43,6 +43,7 @@ clean:
 docs: README.md doc/ctpv.1
 	deptable/list.awk $(PRE) | deptable/markdown.sed | deptable/insert.awk README.md
 	deptable/list.awk $(PRE) | deptable/roff.sed | deptable/insert.awk doc/ctpv.1
+	./updatedate.awk doc/ctpv.1
 
 ctpv: $(OBJ)
 	$(CC) -o $@ $+ $(LDFLAGS)

doc/ctpv.1

@@ -14,7 +14,7 @@
 \&\fB\\$1\fP \fI\\$2\fP\\$3
 ..
 .
-.TH CTPV 1 "July 2022" Linux "User Manuals"
+.TH CTPV 1 2022-07-31 Linux "User Manuals"
 .
 .SH NAME
 ctpv \- terminal previewer

updatedate.awk

@@ -0,0 +1,15 @@
+#!/usr/bin/gawk -f
+
+@include "inplace"
+
+BEGIN {
+    FS = " "
+}
+
+/^\.TH / {
+    cmd = "date +%Y-%m-%d"
+    cmd | getline $4
+    close(cmd)
+}
+
+{ print }