git-compat-util: move strbuf.c funcs to its header

While functions like starts_with() probably should not belong in the
boundaries of the strbuf library, this commit focuses on first splitting
out headers from git-compat-util.h.

Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/strbuf.h b/strbuf.h
index 507670ce3c..a2544484f8 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -735,4 +735,36 @@ char *xstrvfmt(const char *fmt, va_list ap);
 __attribute__((format (printf, 1, 2)))
 char *xstrfmt(const char *fmt, ...);
 
+int starts_with(const char *str, const char *prefix);
+int istarts_with(const char *str, const char *prefix);
+
+/*
+ * If the string "str" is the same as the string in "prefix", then the "arg"
+ * parameter is set to the "def" parameter and 1 is returned.
+ * If the string "str" begins with the string found in "prefix" and then a
+ * "=" sign, then the "arg" parameter is set to "str + strlen(prefix) + 1"
+ * (i.e., to the point in the string right after the prefix and the "=" sign),
+ * and 1 is returned.
+ *
+ * Otherwise, return 0 and leave "arg" untouched.
+ *
+ * When we accept both a "--key" and a "--key=<val>" option, this function
+ * can be used instead of !strcmp(arg, "--key") and then
+ * skip_prefix(arg, "--key=", &arg) to parse such an option.
+ */
+int skip_to_optional_arg_default(const char *str, const char *prefix,
+				 const char **arg, const char *def);
+
+static inline int skip_to_optional_arg(const char *str, const char *prefix,
+				       const char **arg)
+{
+	return skip_to_optional_arg_default(str, prefix, arg, "");
+}
+
+static inline int ends_with(const char *str, const char *suffix)
+{
+	size_t len;
+	return strip_suffix(str, suffix, &len);
+}
+
 #endif /* STRBUF_H */