Solve day 4 part 1

The read builtin returning 1 for EOF when the last line doesn't end with
a newline tripped me up. Only a problem because I like to just
copy the input and use pbpaste, I guess.

1 files changed, 30 insertions, 0 deletions

diff --git a/2020/day04-1.sh b/2020/day04-1.sh
new file mode 100644
index 0000000..afac196
--- /dev/null
+++ b/2020/day04-1.sh
@@ -0,0 +1,30 @@
+#!/bin/sh
+valid=0
+validate() {
+	[ \
+		-n "${byr}" -a \
+		-n "${iyr}" -a \
+		-n "${eyr}" -a \
+		-n "${hgt}" -a \
+		-n "${hcl}" -a \
+		-n "${ecl}" -a \
+		-n "${pid}" \
+	] && valid=$((valid + 1))
+	unset byr iyr eyr hgt hcl ecl pid cid
+}
+while :; do
+	read -r line
+	last=$?
+	if [ -n "${line}" ]; then
+		for pair in $line; do
+			var=${pair%:*}
+			val=${pair#*:}
+			eval "${var}=${val}"
+		done
+	else
+		validate
+	fi
+	[ $last -ne 0 ] && break
+done
+validate
+echo $valid