liblinux++

commit 28b4618122eb17819ebeb2344774c6a47733519b
parent 37dc9cbfdf01c7af51c09c1645d07de844c97ee1
Author: Henry Wilson <henry@henryandlizzy.uk>
Date:   Tue, 23 Dec 2025 00:54:53 +0000

parse integer from string for sleep argument

Diffstat:
M
sleep.cpp
 | 
35
+++++++++++++++++++++++++++++++++--

1 file changed, 33 insertions(+), 2 deletions(-)
diff --git a/sleep.cpp b/sleep.cpp
@@ -1,7 +1,38 @@
 #include "linux.hpp"
 
-int main()
+bool parse_digit(char c, uint64_t& out)
 {
-	timespec duration{1, 0};
+	switch (c)
+	{
+	case '0' ... '9':
+		out = c - '0';
+		return true;
+	default:
+		return false;
+	}
+}
+
+bool parse_u64(char const* p, uint64_t& out)
+{
+	if (!parse_digit(*p, out))
+		return false;
+
+	while (*++p)
+	{
+		uint64_t d;
+		if (not parse_digit(*p, d))
+			return false;
+		out = out * 10 + d;
+	}
+	return true;
+}
+
+int main(int argc, char* argv[])
+{
+	uint64_t n;
+	if (argc != 2 or not parse_u64(argv[1], n))
+		return 1;
+
+	timespec duration{(time_t)n, 0};
     nanosleep(duration, nullptr);
 }