Context code '+' to create context smartly

3 files changed, 32 insertions, 16 deletions

diff --git a/plugins/README.md b/plugins/README.md
index b16ef9e..3067236 100644
--- a/plugins/README.md
+++ b/plugins/README.md
@@ -161,17 +161,25 @@ Plugins can be written in any scripting language. However, POSIX-compliant shell
 
 Drop the plugin in `${XDG_CONFIG_HOME:-$HOME/.config}/nnn/plugins` and make it executable. Optionally add a hotkey in `$NNN_PLUG` for frequent usage.
 
-#### Controlling `nnn`'s active directory
-`nnn` provides a mechanism for plugins to control its active directory.
+#### Send data to `nnn`
+`nnn` provides a mechanism for plugins to send data to `nnn` to control its active directory or invoke the list mode.
 The way to do so is by writing to the pipe pointed by the environment variable `NNN_PIPE`.
-The plugin should write a single string in the format `<context number><char><path>` without a newline at the end. For example, `1c/etc`.
-The context number indicates the context to change the active directory of (0 is used to indicate the current context).
-The `<char>` indicates the operation type.
+The plugin should write a single string in the format `<ctxcode><opcode><data>` without a newline at the end. For example, `1c/etc`.
 
-: Char : Operation :
+The `ctxcode` indicates the context to change the active directory of.
+
+| Context code | Meaning |
+|:---:| --- |
+| `1`-`4` | context number |
+| `0` | current context |
+| `+` | next inactive context or current (if all active) |
+
+The `opcode` indicates the operation type.
+
+| Opcode | Operation |
 |:---:| --- |
-| c | cd |
-| l | list files in list mode |
+| `c` | change directory |
+| `l` | list files in list mode |
 
 For convenience, we provided a helper script named `.nnn-plugin-helper` and a function named `nnn_cd` to ease this process. `nnn_cd` receives the path to change to as the first argument, and the context as an optional second argument.
 If a context is not provided, it is asked for explicitly. To skip this and choose the current context, set the `CUR_CTX` variable in `.nnn-plugin-helper` to `1`.
diff --git a/plugins/mimelist b/plugins/mimelist
index 0ec7c0f..5635afd 100755
--- a/plugins/mimelist
+++ b/plugins/mimelist
@@ -1,6 +1,6 @@
 #!/usr/bin/env sh
 
-# Description: Run fd/find in subtree and list files by mime type in current context
+# Description: Run fd/find in subtree and list files by mime type in smart context
 # Requires: fd/find
 #
 # Shell: POSIX compliant
@@ -17,5 +17,5 @@ fi
 printf "mime: "
 read -r mime
 
-printf "%s" "0l" > "$NNN_PIPE"
+printf "%s" "+l" > "$NNN_PIPE"
 $fd | file -if- | grep "$mime" | awk -F: '{printf "%s\0", $1}' > "$NNN_PIPE"
diff --git a/src/nnn.c b/src/nnn.c
index d9a20df..5e215d7 100644
--- a/src/nnn.c
+++ b/src/nnn.c
@@ -4234,16 +4234,24 @@ static void rmlistpath()
 
 static void readpipe(int fd, char **path, char **lastname, char **lastdir)
 {
-	char *nextpath = NULL;
+	int r;
+	char ctx, *nextpath = NULL;
 	ssize_t len = read(fd, g_buf, 1);
 
 	if (len != 1)
 		return;
 
-	char ctx = g_buf[0] - '0';
-
-	if (ctx > CTX_MAX)
-		return;
+	if (g_buf[0] == '+') {
+		r = cfg.curctx;
+		do
+			r = (r + 1) & ~CTX_MAX;
+		while (g_ctx[r].c_cfg.ctxactive && (r != cfg.curctx));
+		ctx = r + 1;
+	} else {
+		ctx = g_buf[0] - '0';
+		if (ctx > CTX_MAX)
+			return;
+	}
 
 	len = read(fd, g_buf, 1);
 	if (len != 1)
@@ -4269,7 +4277,7 @@ static void readpipe(int fd, char **path, char **lastname, char **lastdir)
 			xstrsncpy(*lastdir, *path, PATH_MAX);
 			xstrsncpy(*path, nextpath, PATH_MAX);
 		} else {
-			int r = ctx - 1;
+			r = ctx - 1;
 
 			g_ctx[r].c_cfg.ctxactive = 0;
 			savecurctx(&cfg, nextpath, dents[cur].name, r);