1 files changed, 116 insertions, 0 deletions
diff --git a/strvec.h b/strvec.h
new file mode 100644
index 0000000000..f74e061e14
--- /dev/null
+++ b/strvec.h
@@ -0,0 +1,116 @@
+#ifndef STRVEC_H
+#define STRVEC_H
+
+/**
+ * The strvec API allows one to dynamically build and store
+ * NULL-terminated arrays of strings. A strvec maintains the invariant that the
+ * `v` member always points to a non-NULL array, and that the array is
+ * always NULL-terminated at the element pointed to by `v[nr]`. This
+ * makes the result suitable for passing to functions expecting to receive
+ * argv from main().
+ *
+ * The string-list API (documented in string-list.h) is similar, but cannot be
+ * used for these purposes; instead of storing a straight string pointer,
+ * it contains an item structure with a `util` field that is not compatible
+ * with the traditional argv interface.
+ *
+ * Each `strvec` manages its own memory. Any strings pushed into the
+ * array are duplicated, and all memory is freed by strvec_clear().
+ */
+
+extern const char *empty_strvec[];
+
+/**
+ * A single array. This should be initialized by assignment from
+ * `STRVEC_INIT`, or by calling `strvec_init`. The `v`
+ * member contains the actual array; the `nr` member contains the
+ * number of elements in the array, not including the terminating
+ * NULL.
+ */
+struct strvec {
+	const char **v;
+	size_t nr;
+	size_t alloc;
+};
+
+#define STRVEC_INIT { \
+	.v = empty_strvec, \
+}
+
+/**
+ * Initialize an array. This is no different than assigning from
+ * `STRVEC_INIT`.
+ */
+void strvec_init(struct strvec *);
+
+/* Push a copy of a string onto the end of the array. */
+const char *strvec_push(struct strvec *, const char *);
+
+/* Push an allocated string onto the end of the array, taking ownership. */
+void strvec_push_nodup(struct strvec *array, char *value);
+
+/**
+ * Format a string and push it onto the end of the array. This is a
+ * convenience wrapper combining `strbuf_addf` and `strvec_push`.
+ */
+__attribute__((format (printf,2,3)))
+const char *strvec_pushf(struct strvec *, const char *fmt, ...);
+
+/**
+ * Push a list of strings onto the end of the array. The arguments
+ * should be a list of `const char *` strings, terminated by a NULL
+ * argument.
+ */
+LAST_ARG_MUST_BE_NULL
+void strvec_pushl(struct strvec *, ...);
+
+/* Push a null-terminated array of strings onto the end of the array. */
+void strvec_pushv(struct strvec *, const char **);
+
+/*
+ * Replace `len` values starting at `idx` with the provided replacement
+ * strings. If `len` is zero this is effectively an insert at the given `idx`.
+ * If `replacement_len` is zero this is effectively a delete of `len` items
+ * starting at `idx`.
+ */
+void strvec_splice(struct strvec *array, size_t idx, size_t len,
+		   const char **replacement, size_t replacement_len);
+
+/**
+ * Replace the value at the given index with a new value. The index must be
+ * valid. Returns a pointer to the inserted value.
+ */
+const char *strvec_replace(struct strvec *array, size_t idx, const char *replacement);
+
+/*
+ * Remove the value at the given index. The remainder of the array will be
+ * moved to fill the resulting gap. The provided index must point into the
+ * array.
+ */
+void strvec_remove(struct strvec *array, size_t idx);
+
+/**
+ * Remove the final element from the array. If there are no
+ * elements in the array, do nothing.
+ */
+void strvec_pop(struct strvec *);
+
+/* Splits by whitespace; does not handle quoted arguments! */
+void strvec_split(struct strvec *, const char *);
+
+/**
+ * Free all memory associated with the array and return it to the
+ * initial, empty state.
+ */
+void strvec_clear(struct strvec *);
+
+/**
+ * Disconnect the `v` member from the `strvec` struct and
+ * return it. The caller is responsible for freeing the memory used
+ * by the array, and by the strings it references. After detaching,
+ * the `strvec` is in a reinitialized state and can be pushed
+ * into again.
+ */
+const char **strvec_detach(struct strvec *);
+
+#endif /* STRVEC_H */