1 files changed, 144 insertions, 0 deletions
diff --git a/strtotimespec.c b/strtotimespec.c
new file mode 100644
index 0000000..b8a7489
--- /dev/null
+++ b/strtotimespec.c
@@ -0,0 +1,144 @@
+/* See LICENSE file for copyright and license details. */
+#include "libsimple.h"
+
+
+int
+libsimple_strtotimespec(struct timespec *restrict ts, const char *restrict s, char **restrict end)
+{
+	int neg = 0, bracket = 0;
+	time_t sec = 0;
+	long int nsec = 0;
+	long int mul = 100000000L;
+	const char *p;
+
+	if (end)
+		*end = (void *)s;
+
+	while (isspace(*s))
+		s++;
+
+	if (!isdigit(s) && *s != '+' && *s != '-' && *s != '.') {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (*s == '-') {
+		neg = 1;
+		s++;
+	} else if (*s == '+') {
+		s++;
+	}
+
+	if (*s == '.') {
+		if (s[1] == '.' || s[1] == '(') {
+			if (!isdigit(s[2])) {
+				errno = EINVAL;
+				return -1;
+			}
+		} else if (!isdigit(s[1])) {
+			errno = EINVAL;
+			return -1;
+		}
+	}
+
+	for (; isdigit(*s); s++) {
+		if (sec < TIME_MIN / 10)
+			goto overflow;
+		sec *= 10;
+		if (sec < TIME_MIN + (*s & 15))
+			goto overflow;
+		sec -= *s & 15;
+	}
+
+	if (!neg) {
+		if (TIME_MIN != -TIME_MAX && sec == TIME_MIN)
+			goto overflow;
+		sec = -sec;
+	}
+
+	if (*s != '.') {
+		ts->tv_sec = sec;
+		ts->tv_nsec = 0;
+		if (end)
+			*end = (void *)s;
+		return 0;
+	}
+
+	for (s++; mul && isdigit(*s); s++) {
+		nsec += (*s & 15) * mul;
+		mul /= 10;
+	}
+
+	if (*s == '.' || *s == '(') {
+		bracket = *s++ == '(';
+		p = s;
+		if (!isdigit(*s)) {
+			errno = EINVAL;
+			return -1;
+		}
+		for (p = s; isdigit(*p); p++);
+		if (bracket) {
+			if (*p == ')') {
+				p++;
+			} else {
+				errno = EINVAL;
+				return -1;
+			}
+		}
+		if (end)
+			*end = (void *)p;
+		p = s;
+		while (mul) {
+			for (s = p; mul && isdigit(*s); s++) {
+				nsec += (*s & 15) * mul;
+				mul /= 10;
+			}
+		}
+		if (!isdigit(*s))
+			s = p;
+		if (*s >= '5') {
+			nsec += 1;
+			if (nsec == 1000000000L) {
+				if (sec == TIME_MAX)
+					goto overflow;
+				sec += 1;
+				nsec = 0;
+			}
+		}
+	} else {
+		if (isdigit(*s)) {
+			if (*s >= '5') {
+				nsec += 1;
+				if (nsec == 1000000000L) {
+					if (sec == TIME_MAX)
+						goto overflow;
+					sec += 1;
+					nsec = 0;
+				}
+			}
+			while (isdigit(*s))
+				s++;
+		}
+		if (end)
+			*end = (void *)s;
+	}
+
+	if (neg && nsec) {
+		if (sec == TIME_MIN)
+			goto overflow;
+		nsec = 1000000000L - nsec;
+		sec -= 1;
+	}
+
+	return 0;
+overflow:
+	if (neg) {
+		ts->tv_sec = TIME_MIN;
+		ts->tv_nsec = 0;
+	} else {
+		ts->tv_sec = TIME_MAX;
+		ts->tv_nsec = 999999999L;
+	}
+	errno = ERANGE;
+	return -1;
+}