Implement pl_env_vars option for library/playlist/cache relocation

Doc/cmus.txt

@@ -1115,6 +1115,12 @@ pause_on_output_change (false)
 
     Supported output plugins: pulse.
 
+pl_env_vars
+	Comma separated list of environment variables to substitute when saving
+	library/playlist files. The paths must be absolute to take effect.
+
+	Note: This option will not take full effect until cmus has been restarted.
+
 pl_sort () [`Sort Keys`]
 	Sort keys for the playlist view (3). Empty value disables sorting and
 	enables manually moving tracks.

Makefile

@@ -40,9 +40,9 @@ cmus-y := \
 	comment.o convert.lo cue.o cue_utils.o debug.o discid.o editable.o expr.o \
 	filters.o format_print.o gbuf.o glob.o help.o history.o http.o id3.o input.o \
 	job.o keys.o keyval.o lib.o load_dir.o locking.o mergesort.o misc.o options.o \
-	output.o pcm.o player.o play_queue.o pl.o rbtree.o read_wrapper.o search_mode.o \
-	search.o server.o spawn.o tabexp_file.o tabexp.o track_info.o track.o tree.o \
-	uchar.o u_collate.o ui_curses.o window.o worker.o xstrjoin.o
+	output.o pcm.o player.o play_queue.o pl.o pl_env.o rbtree.o read_wrapper.o \
+	search_mode.o search.o server.o spawn.o tabexp_file.o tabexp.o track_info.o \
+	track.o tree.o uchar.o u_collate.o ui_curses.o window.o worker.o xstrjoin.o
 
 cmus-$(CONFIG_MPRIS) += mpris.o
 

cache.c

@@ -26,6 +26,7 @@
 #include "xstrjoin.h"
 #include "gbuf.h"
 #include "options.h"
+#include "pl_env.h"
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -124,10 +125,18 @@ static int valid_cache_entry(const struct cache_entry *e, unsigned int avail)
 static struct track_info *cache_entry_to_ti(struct cache_entry *e)
 {
 	const char *strings = e->strings;
-	struct track_info *ti = track_info_new(strings);
+	struct track_info *ti;
 	struct keyval *kv;
 	int str_size = e->size - sizeof(*e);
 	int pos, i, count;
+	char *proc_filename;
+
+	if (pl_env_var(strings, NULL) && (proc_filename = pl_env_expand(strings))) {
+		ti = track_info_new(proc_filename);
+		free(proc_filename);
+	} else {
+		ti = track_info_new(strings);
+	}
 
 	ti->duration = e->duration;
 	ti->bitrate = e->bitrate;
@@ -318,6 +327,7 @@ static void flush_buffer(int fd, struct gbuf *buf)
 
 static void write_ti(int fd, struct gbuf *buf, struct track_info *ti, unsigned int *offsetp)
 {
+	char *proc_filename = pl_env_reduce(ti->filename);
 	const struct keyval *kv = ti->comments;
 	unsigned int offset = *offsetp;
 	unsigned int pad;
@@ -334,7 +344,7 @@ static void write_ti(int fd, struct gbuf *buf, struct track_info *ti, unsigned i
 	e.mtime = ti->mtime;
 	e.play_count = ti->play_count;
 	e.bpm = ti->bpm;
-	len[count] = strlen(ti->filename) + 1;
+	len[count] = strlen(proc_filename) + 1;
 	e.size += len[count++];
 	len[count] = (ti->codec ? strlen(ti->codec) : 0) + 1;
 	e.size += len[count++];
@@ -359,7 +369,7 @@ static void write_ti(int fd, struct gbuf *buf, struct track_info *ti, unsigned i
 	if (pad)
 		gbuf_set(buf, 0, pad);
 	gbuf_add_bytes(buf, &e, sizeof(e));
-	gbuf_add_bytes(buf, ti->filename, len[count++]);
+	gbuf_add_bytes(buf, proc_filename, len[count++]);
 	gbuf_add_bytes(buf, ti->codec ? ti->codec : "", len[count++]);
 	gbuf_add_bytes(buf, ti->codec_profile ? ti->codec_profile : "", len[count++]);
 	for (i = 0; kv[i].key; i++) {
@@ -369,6 +379,8 @@ static void write_ti(int fd, struct gbuf *buf, struct track_info *ti, unsigned i
 
 	free(len);
 	*offsetp = offset + pad + e.size;
+
+	free(proc_filename);
 }
 
 int cache_close(void)
@@ -437,6 +449,18 @@ struct track_info *cache_get_ti(const char *filename, int force)
 	struct track_info *ti;
 	int reload = 0;
 
+	if (pl_env_var(filename, NULL)) {
+		struct growing_keyvals c = {NULL, 0, 0};
+		keyvals_terminate(&c);
+
+		ti = track_info_new(filename);
+		ti->duration = 0;
+		track_info_set_comments(ti, c.keyvals);
+
+		track_info_ref(ti);
+		return ti;
+	}
+
 	ti = lookup_cache_entry(filename, hash);
 	if (ti) {
 		if ((!skip_track_info && ti->duration == 0 && !is_http_url(filename)) || force){

cmus.c

@@ -38,6 +38,7 @@
 #include "gbuf.h"
 #include "discid.h"
 #include "locking.h"
+#include "pl_env.h"
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -231,16 +232,20 @@ static int save_ext_playlist_cb(void *data, struct track_info *ti)
 
 static int save_playlist_cb(void *data, struct track_info *ti)
 {
+	char *proc_filename = pl_env_reduce(ti->filename);
 	int fd = *(int *)data;
 	const char nl = '\n';
 	int rc;
 
-	rc = write_all(fd, ti->filename, strlen(ti->filename));
+	rc = write_all(fd, proc_filename, strlen(proc_filename));
+	free(proc_filename);
 	if (rc == -1)
 		return -1;
+
 	rc = write_all(fd, &nl, 1);
 	if (rc == -1)
 		return -1;
+
 	return 0;
 }
 

job.c

@@ -36,6 +36,7 @@
 #include "xstrjoin.h"
 #include "ui_curses.h"
 #include "cue_utils.h"
+#include "pl_env.h"
 
 #include <string.h>
 #include <unistd.h>
@@ -351,7 +352,9 @@ static int handle_line(void *data, const char *line)
 	if (is_http_url(line) || is_cue_url(line)) {
 		add_url(line);
 	} else {
-		char *absolute = path_absolute_cwd(line, data);
+		char *absolute = pl_env_var(line, NULL)
+			? pl_env_expand(line)
+			: path_absolute_cwd(line, data);
 		add_file(absolute, 0);
 		free(absolute);
 	}

options.c

@@ -160,6 +160,7 @@ char *window_title_alt_format = NULL;
 char *id3_default_charset = NULL;
 char *icecast_default_charset = NULL;
 char *lib_add_filter = NULL;
+char **pl_env_vars;
 
 static void buf_int(char *buf, int val, size_t size)
 {
@@ -268,6 +269,7 @@ static const struct {
 	{ "pl_sort", "" },
 	{ "id3_default_charset", "ISO-8859-1" },
 	{ "icecast_default_charset", "ISO-8859-1" },
+	{ "pl_env_vars", "" },
 	{ NULL, NULL }
 };
 
@@ -507,6 +509,56 @@ static void set_tree_width_max(void *data, const char *buf)
 	update_size();
 }
 
+/* get_pl_env_vars converts the pl_env_vars array into a comma-separated list */
+static void get_pl_env_vars(void *data, char *buf, size_t size)
+{
+	if (!pl_env_vars) {
+		strscpy(buf, "", size);
+		return;
+	}
+	char *p = buf;
+	size_t r = size - 1;
+	for (char **x = pl_env_vars; *x; x++) {
+		if (x != pl_env_vars) {
+			if (!--r)
+				return; /* overflow */
+			*p++ = ',';
+		}
+		size_t l = strlen(*x);
+		if (!(r -= l))
+			return; /* overflow */
+		strcpy(p, *x);
+		p += l;
+	}
+	*p = '\0';
+}
+
+/* set_pl_env_vars splits the pl_env_vars config into the pl_env_vars array */
+static void set_pl_env_vars(void *data, const char *buf)
+{
+	if (pl_env_vars) {
+		free(*pl_env_vars);
+		free(pl_env_vars);
+	}
+	if (!*buf) {
+		pl_env_vars = NULL;
+	}
+	size_t n = 1;
+	for (const char *x = buf; *x; x++) {
+		if (*x == ',') {
+			n++;
+		}
+	}
+	char **a = pl_env_vars = xnew(char*, n+1);
+	for (char *x = *a++ = xstrdup(buf); *x; x++) {
+		if (*x == ',') {
+			*a++ = x+1;
+			*x = '\0';
+		}
+	}
+	*a = NULL;
+}
+
 /* }}} */
 
 /* callbacks for toggle options {{{ */
@@ -1516,6 +1568,7 @@ static const struct {
 	DN(tree_width_percent)
 	DN(tree_width_max)
 	DT(pause_on_output_change)
+	DN(pl_env_vars)
 	{ NULL, NULL, NULL, NULL, 0 }
 };
 

options.h

@@ -203,6 +203,9 @@ extern char *clipped_text_internal;
 extern char *id3_default_charset;
 extern char *icecast_default_charset;
 
+/* comma-separated list of env vars to substitute in saved library/cache paths */
+extern char **pl_env_vars;
+
 /* build option list */
 void options_add(void);