1 files changed, 182 insertions, 0 deletions
diff --git a/parse.c b/parse.c
new file mode 100644
index 0000000000..42d691a0fb
--- /dev/null
+++ b/parse.c
@@ -0,0 +1,182 @@
+#include "git-compat-util.h"
+#include "gettext.h"
+#include "parse.h"
+
+static uintmax_t get_unit_factor(const char *end)
+{
+	if (!*end)
+		return 1;
+	else if (!strcasecmp(end, "k"))
+		return 1024;
+	else if (!strcasecmp(end, "m"))
+		return 1024 * 1024;
+	else if (!strcasecmp(end, "g"))
+		return 1024 * 1024 * 1024;
+	return 0;
+}
+
+int git_parse_signed(const char *value, intmax_t *ret, intmax_t max)
+{
+	if (value && *value) {
+		char *end;
+		intmax_t val;
+		intmax_t factor;
+
+		if (max < 0)
+			BUG("max must be a positive integer");
+
+		errno = 0;
+		val = strtoimax(value, &end, 0);
+		if (errno == ERANGE)
+			return 0;
+		if (end == value) {
+			errno = EINVAL;
+			return 0;
+		}
+		factor = get_unit_factor(end);
+		if (!factor) {
+			errno = EINVAL;
+			return 0;
+		}
+		if ((val < 0 && -max / factor > val) ||
+		    (val > 0 && max / factor < val)) {
+			errno = ERANGE;
+			return 0;
+		}
+		val *= factor;
+		*ret = val;
+		return 1;
+	}
+	errno = EINVAL;
+	return 0;
+}
+
+static int git_parse_unsigned(const char *value, uintmax_t *ret, uintmax_t max)
+{
+	if (value && *value) {
+		char *end;
+		uintmax_t val;
+		uintmax_t factor;
+
+		/* negative values would be accepted by strtoumax */
+		if (strchr(value, '-')) {
+			errno = EINVAL;
+			return 0;
+		}
+		errno = 0;
+		val = strtoumax(value, &end, 0);
+		if (errno == ERANGE)
+			return 0;
+		if (end == value) {
+			errno = EINVAL;
+			return 0;
+		}
+		factor = get_unit_factor(end);
+		if (!factor) {
+			errno = EINVAL;
+			return 0;
+		}
+		if (unsigned_mult_overflows(factor, val) ||
+		    factor * val > max) {
+			errno = ERANGE;
+			return 0;
+		}
+		val *= factor;
+		*ret = val;
+		return 1;
+	}
+	errno = EINVAL;
+	return 0;
+}
+
+int git_parse_int(const char *value, int *ret)
+{
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_int64(const char *value, int64_t *ret)
+{
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int64_t)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_ulong(const char *value, unsigned long *ret)
+{
+	uintmax_t tmp;
+	if (!git_parse_unsigned(value, &tmp, maximum_unsigned_value_of_type(long)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_ssize_t(const char *value, ssize_t *ret)
+{
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(ssize_t)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_maybe_bool_text(const char *value)
+{
+	if (!value)
+		return 1;
+	if (!*value)
+		return 0;
+	if (!strcasecmp(value, "true")
+	    || !strcasecmp(value, "yes")
+	    || !strcasecmp(value, "on"))
+		return 1;
+	if (!strcasecmp(value, "false")
+	    || !strcasecmp(value, "no")
+	    || !strcasecmp(value, "off"))
+		return 0;
+	return -1;
+}
+
+int git_parse_maybe_bool(const char *value)
+{
+	int v = git_parse_maybe_bool_text(value);
+	if (0 <= v)
+		return v;
+	if (git_parse_int(value, &v))
+		return !!v;
+	return -1;
+}
+
+/*
+ * Parse environment variable 'k' as a boolean (in various
+ * possible spellings); if missing, use the default value 'def'.
+ */
+int git_env_bool(const char *k, int def)
+{
+	const char *v = getenv(k);
+	int val;
+	if (!v)
+		return def;
+	val = git_parse_maybe_bool(v);
+	if (val < 0)
+		die(_("bad boolean environment value '%s' for '%s'"),
+		    v, k);
+	return val;
+}
+
+/*
+ * Parse environment variable 'k' as ulong with possibly a unit
+ * suffix; if missing, use the default value 'val'.
+ */
+unsigned long git_env_ulong(const char *k, unsigned long val)
+{
+	const char *v = getenv(k);
+	if (v && !git_parse_ulong(v, &val))
+		die(_("failed to parse %s"), k);
+	return val;
+}