scan: Prefer comma instead of colon for backends separator

Libiio 1.x (in the dev branch) uses a comma instead of a colon as the
backends separator in the scan list string. This makes it possible to
use the colon as the VID/PID separator in the USB backend parameters.

Update the code and documentation to specify that commas should be used,
while still allowing colons as separators to be backwards-compatible.

Signed-off-by: Paul Cercueil <[email protected]>

Author: pcercuei

iio.h

@@ -236,13 +236,18 @@ enum iio_event_direction {
 
 
 /** @brief Create a scan context
- * @param backend A NULL-terminated string containing the backend(s) to use for
- * scanning (example: pre version 0.20 :  "local", "ip", or "usb"; post version
- * 0.20 can handle multiple, including "local:usb:", "ip:usb:", "local:usb:ip:").
- * If NULL, all the available backends are used.
+ * @param backend A NULL-terminated string containing a comma-separated
+ * list of the backend(s) to use for scanning.
  * @param flags Unused for now. Set to 0.
  * @return on success, a pointer to a iio_scan_context structure
- * @return On failure, NULL is returned and errno is set appropriately */
+ * @return On failure, NULL is returned and errno is set appropriately
+ *
+ * <b>NOTE:</b> Libiio version 0.20 and above can handle multiple
+ * strings, for instance "local:usb:", "ip:usb:", "local:usb:ip:", and
+ * require a colon as the delimiter. If NULL, the local, USB and IP
+ * backends will be scanned.
+ * Libiio version 0.24 and above prefer a comma instead of colon as the
+ * delimiter. */
 __api __check_ret struct iio_scan_context * iio_create_scan_context(
 		const char *backend, unsigned int flags);
 

scan.c

@@ -36,8 +36,8 @@ ssize_t iio_scan_context_get_info_list(struct iio_scan_context *ctx,
 	char *token, *rest=NULL;
 	ssize_t ret;
 
-	for (token = iio_strtok_r(ctx->backendopts, ":", &rest);
-			token; token = iio_strtok_r(NULL, ":", &rest)) {
+	for (token = iio_strtok_r(ctx->backendopts, ",", &rest);
+			token; token = iio_strtok_r(NULL, ",", &rest)) {
 
 		/* Since tokens are all null terminated, it's safe to use strcmp on them */
 		if (WITH_LOCAL_BACKEND && !strcmp(token, "local")) {
@@ -108,6 +108,7 @@ struct iio_scan_context * iio_create_scan_context(
 		const char *backend, unsigned int flags)
 {
 	struct iio_scan_context *ctx;
+	unsigned int i, len;
 
 	/* "flags" must be zero for now */
 	if (flags != 0) {
@@ -121,13 +122,21 @@ struct iio_scan_context * iio_create_scan_context(
 		return NULL;
 	}
 
-	ctx->backendopts = iio_strndup(backend ? backend : "local:usb:ip", PATH_MAX);
+	ctx->backendopts = iio_strndup(backend ? backend : "local,usb,ip", PATH_MAX);
 	if (!ctx->backendopts) {
 		free(ctx);
 		errno = ENOMEM;
 		return NULL;
 	}
 
+	if (backend) {
+		/* Replace the colon separator with a comma. */
+		len = strlen(ctx->backendopts);
+		for (i = 0; i < len; i++)
+			if (ctx->backendopts[i] == ':')
+				ctx->backendopts[i] = ',';
+	}
+
 	return ctx;
 }