Introduce shell_expand

This performs shell expansion without field splitting. This fixes issues with
filenames containing spaces.

This commit also cleans up complicated logic to join fields and to set
XDG_CONFIG_HOME.

common/meson.build

@@ -4,14 +4,15 @@ lib_sway_common = static_library(
 		'background-image.c',
 		'cairo.c',
 		'ipc-client.c',
+		'list.c',
 		'log.c',
 		'loop.c',
-		'list.c',
 		'pango.c',
 		'readline.c',
+		'shexp.c',
 		'stringop.c',
 		'unicode.c',
-		'util.c'
+		'util.c',
 	),
 	dependencies: [
 		cairo,

common/shexp.c

@@ -0,0 +1,51 @@
+#define _POSIX_C_SOURCE 200809L
+#include <stdlib.h>
+#include <string.h>
+#include <wordexp.h>
+#include "shexp.h"
+
+static const char escaped_quote[] = "'\"'\"'";
+
+static char *escape(const char *str) {
+	size_t escaped_len = 2; // quotes at the begining and end
+	for (size_t i = 0; str[i] != '\0'; ++i) {
+		if (str[i] == '\'') {
+			escaped_len += strlen(escaped_quote);
+		} else {
+			++escaped_len;
+		}
+	}
+
+	char *escaped = malloc(escaped_len + 1);
+	escaped[0] = '\'';
+	size_t j = 1;
+	for (size_t i = 0; str[i] != '\0'; ++i) {
+		if (str[i] == '\'') {
+			memcpy(&escaped[j], escaped_quote, strlen(escaped_quote));
+			j += strlen(escaped_quote);
+		} else {
+			escaped[j] = str[i];
+			++j;
+		}
+	}
+	escaped[j] = '\'';
+	escaped[j + 1] = '\0';
+
+	return escaped;
+}
+
+bool shell_expand(char **path) {
+	char *escaped_path = escape(*path);
+
+	wordexp_t p;
+	bool ret = false;
+	if (wordexp(escaped_path, &p, WRDE_UNDEF) == 0) {
+		free(*path);
+		*path = strdup(p.we_wordv[0]);
+		wordfree(&p);
+		ret = true;
+	}
+
+	free(escaped_path);
+	return ret;
+}

include/shexp.h

@@ -0,0 +1,14 @@
+#ifndef _SWAY_SHEXP_H
+#define _SWAY_SHEXP_H
+
+#include <stdbool.h>
+
+/**
+ * Takes a pointer to a string and reallocates it with the result of its shell
+ * expansion. Undefined environment variables are considered as errors. Returns
+ * true if it succeeds, otherwise returns false, leaving the original string
+ * unchanged.
+ */
+bool shell_expand(char **path);
+
+#endif

sway/commands/output/background.c

@@ -1,14 +1,14 @@
 #define _POSIX_C_SOURCE 200809
+#include <errno.h>
 #include <libgen.h>
 #include <strings.h>
 #include <unistd.h>
-#include <wordexp.h>
-#include <errno.h>
+#include "log.h"
+#include "shexp.h"
+#include "stringop.h"
 #include "sway/commands.h"
 #include "sway/config.h"
 #include "sway/swaynag.h"
-#include "log.h"
-#include "stringop.h"
 
 static const char *bg_options[] = {
 	"stretch",
@@ -61,28 +61,10 @@ struct cmd_results *output_cmd_background(int argc, char **argv) {
 				"Missing background scaling mode.");
 		}
 
-		wordexp_t p = {0};
 		char *src = join_args(argv, j);
-		while (strstr(src, "  ")) {
-			src = realloc(src, strlen(src) + 2);
-			char *ptr = strstr(src, "  ") + 1;
-			memmove(ptr + 1, ptr, strlen(ptr) + 1);
-			*ptr = '\\';
-		}
-		if (wordexp(src, &p, 0) != 0 || p.we_wordv[0] == NULL) {
-			struct cmd_results *cmd_res = cmd_results_new(CMD_INVALID, "output",
+		if (!shell_expand(&src)) {
+			return cmd_results_new(CMD_INVALID, "output",
 				"Invalid syntax (%s)", src);
-			free(src);
-			wordfree(&p);
-			return cmd_res;
-		}
-		free(src);
-		src = join_args(p.we_wordv, p.we_wordc);
-		wordfree(&p);
-		if (!src) {
-			wlr_log(WLR_ERROR, "Failed to duplicate string");
-			return cmd_results_new(CMD_FAILURE, "output",
-				"Unable to allocate resource");
 		}
 
 		if (config->reading && *src != '/') {
@@ -154,4 +136,3 @@ struct cmd_results *output_cmd_background(int argc, char **argv) {
 	config->handler_context.leftovers.argv = argv;
 	return NULL;
 }
-

sway/config.c

@@ -1,39 +1,40 @@
 #define _XOPEN_SOURCE 600 // for realpath
-#include <stdio.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <unistd.h>
+#include <dirent.h>
 #include <libgen.h>
-#include <wordexp.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <sys/stat.h>
-#include <signal.h>
 #include <libinput.h>
 #include <limits.h>
-#include <dirent.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <strings.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <wordexp.h>
 #ifdef __linux__
 #include <linux/input-event-codes.h>
 #elif __FreeBSD__
 #include <dev/evdev/input-event-codes.h>
 #endif
 #include <wlr/types/wlr_output.h>
-#include "sway/input/input-manager.h"
-#include "sway/input/seat.h"
+#include "cairo.h"
+#include "list.h"
+#include "log.h"
+#include "pango.h"
+#include "readline.h"
+#include "shexp.h"
+#include "stringop.h"
 #include "sway/commands.h"
 #include "sway/config.h"
 #include "sway/criteria.h"
+#include "sway/input/input-manager.h"
+#include "sway/input/seat.h"
 #include "sway/swaynag.h"
 #include "sway/tree/arrange.h"
 #include "sway/tree/root.h"
 #include "sway/tree/workspace.h"
-#include "cairo.h"
-#include "pango.h"
-#include "readline.h"
-#include "stringop.h"
-#include "list.h"
-#include "log.h"
 
 struct sway_config *config = NULL;
 
@@ -321,15 +322,11 @@ static char *get_config_path(void) {
 	}
 
 	for (size_t i = 0; i < sizeof(config_paths) / sizeof(char *); ++i) {
-		wordexp_t p;
-		if (wordexp(config_paths[i], &p, WRDE_UNDEF) == 0) {
-			char *path = strdup(p.we_wordv[0]);
-			wordfree(&p);
-			if (file_exists(path)) {
-				return path;
-			}
-			free(path);
+		char *path = strdup(config_paths[i]);
+		if (shell_expand(&path) && file_exists(path)) {
+			return path;
 		}
+		free(path);
 	}
 
 	return NULL;
@@ -545,17 +542,14 @@ bool load_include_configs(const char *path, struct sway_config *config,
 	}
 
 	wordexp_t p;
-
-	if (wordexp(path, &p, 0) < 0) {
+	if (wordexp(path, &p, WRDE_UNDEF) < 0) {
 		free(parent_path);
 		free(wd);
 		return false;
 	}
 
-	char **w = p.we_wordv;
-	size_t i;
-	for (i = 0; i < p.we_wordc; ++i) {
-		load_include_config(w[i], parent_dir, config, swaynag);
+	for (size_t i = 0; i < p.we_wordc; ++i) {
+		load_include_config(p.we_wordv[i], parent_dir, config, swaynag);
 	}
 	free(parent_path);
 	wordfree(&p);

sway/config/bar.c

@@ -3,7 +3,6 @@
 #include <stdbool.h>
 #include <stdlib.h>
 #include <unistd.h>
-#include <wordexp.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <sys/stat.h>

swaylock/main.c

@@ -14,17 +14,17 @@
 #include <time.h>
 #include <unistd.h>
 #include <wayland-client.h>
-#include <wordexp.h>
 #include <wlr/util/log.h>
-#include "swaylock/seat.h"
-#include "swaylock/swaylock.h"
 #include "background-image.h"
-#include "pool-buffer.h"
 #include "cairo.h"
 #include "log.h"
 #include "loop.h"
+#include "pool-buffer.h"
 #include "readline.h"
+#include "shexp.h"
 #include "stringop.h"
+#include "swaylock/seat.h"
+#include "swaylock/swaylock.h"
 #include "util.h"
 #include "wlr-input-inhibitor-unstable-v1-client-protocol.h"
 #include "wlr-layer-shell-unstable-v1-client-protocol.h"
@@ -375,12 +375,7 @@ static void load_image(char *arg, struct swaylock_state *state) {
 	}
 
 	// Bash doesn't replace the ~ with $HOME if the output name is supplied
-	wordexp_t p;
-	if (wordexp(image->path, &p, 0) == 0) {
-		free(image->path);
-		image->path = strdup(p.we_wordv[0]);
-		wordfree(&p);
-	}
+	shell_expand(&image->path);
 
 	// Load the actual image
 	image->cairo_surface = load_background_image(image->path);
@@ -771,31 +766,17 @@ static char *get_config_path(void) {
 		SYSCONFDIR "/swaylock/config",
 	};
 
-	if (!getenv("XDG_CONFIG_HOME")) {
-		char *home = getenv("HOME");
-		char *config_home = malloc(strlen(home) + strlen("/.config") + 1);
-		if (!config_home) {
-			wlr_log(WLR_ERROR, "Unable to allocate $HOME/.config");
-		} else {
-			strcpy(config_home, home);
-			strcat(config_home, "/.config");
-			setenv("XDG_CONFIG_HOME", config_home, 1);
-			wlr_log(WLR_DEBUG, "Set XDG_CONFIG_HOME to %s", config_home);
-			free(config_home);
-		}
+	char *config_home = getenv("XDG_CONFIG_HOME");
+	if (config_home == NULL || config_home[0] == '\0') {
+		config_paths[1] = "$HOME/.config/swaylock/config";
 	}
 
-	wordexp_t p;
-	char *path;
 	for (size_t i = 0; i < sizeof(config_paths) / sizeof(char *); ++i) {
-		if (wordexp(config_paths[i], &p, 0) == 0) {
-			path = strdup(p.we_wordv[0]);
-			wordfree(&p);
-			if (file_exists(path)) {
-				return path;
-			}
-			free(path);
+		char *path = strdup(config_paths[i]);
+		if (shell_expand(&path) && file_exists(path)) {
+			return path;
 		}
+		free(path);
 	}
 
 	return NULL;

swaynag/config.c

@@ -1,10 +1,10 @@
 #define _POSIX_C_SOURCE 200809L
 #include <getopt.h>
 #include <stdlib.h>
-#include <wordexp.h>
-#include "log.h"
 #include "list.h"
+#include "log.h"
 #include "readline.h"
+#include "shexp.h"
 #include "swaynag/swaynag.h"
 #include "swaynag/types.h"
 #include "util.h"
@@ -306,31 +306,17 @@ char *swaynag_get_config_path(void) {
 		SYSCONFDIR "/swaynag/config",
 	};
 
-	if (!getenv("XDG_CONFIG_HOME")) {
-		char *home = getenv("HOME");
-		char *config_home = malloc(strlen(home) + strlen("/.config") + 1);
-		if (!config_home) {
-			wlr_log(WLR_ERROR, "Unable to allocate $HOME/.config");
-		} else {
-			strcpy(config_home, home);
-			strcat(config_home, "/.config");
-			setenv("XDG_CONFIG_HOME", config_home, 1);
-			wlr_log(WLR_DEBUG, "Set XDG_CONFIG_HOME to %s", config_home);
-			free(config_home);
-		}
+	char *config_home = getenv("XDG_CONFIG_HOME");
+	if (config_home == NULL || config_home[0] == '\0') {
+		config_paths[1] = "$HOME/.config/swaynag/config";
 	}
 
-	wordexp_t p;
-	char *path;
 	for (size_t i = 0; i < sizeof(config_paths) / sizeof(char *); ++i) {
-		if (wordexp(config_paths[i], &p, 0) == 0) {
-			path = strdup(p.we_wordv[0]);
-			wordfree(&p);
-			if (file_exists(path)) {
-				return path;
-			}
-			free(path);
+		char *path = strdup(config_paths[i]);
+		if (shell_expand(&path) && file_exists(path)) {
+			return path;
 		}
+		free(path);
 	}
 
 	return NULL;