Sway: Configuration: Support for escaping line breaks.

Escape line return in configuration file with the '\' character. Similar
to shell scripts.

Signed-off-by: Roosembert Palacios <roosembert.palacios@epfl.ch>

2 files changed, 47 insertions, 1 deletions

diff --git a/sway/config.c b/sway/config.c
index 15108123..c1eec22f 100644
--- a/sway/config.c
+++ b/sway/config.c
@@ -455,10 +455,11 @@ bool load_include_configs(const char *path, struct sway_config *config) {
 
 bool read_config(FILE *file, struct sway_config *config) {
         bool success = true;
+        bool multiline = false;
         enum cmd_status block = CMD_BLOCK_END;
 
         int line_number = 0;
-        char *line;
+        char *line, *mlinebuf = NULL;
         while (!feof(file)) {
                 line = read_line(file);
                 line_number++;
@@ -467,6 +468,45 @@ bool read_config(FILE *file, struct sway_config *config) {
                         free(line);
                         continue;
                 }
+                size_t length = strlen(line);
+                if (line[length-1] == '\\') {
+                        // Start of multiline
+                        if (feof(file)){
+                                sway_log(L_ERROR, "Error on line %i '%s': Unexpected EOF on "\
+                                                "multiline command", line_number, line);
+                                free(line);
+                                continue;
+                        }
+                        line[length-1] = '\0';
+                        multiline = true;
+                } else
+                        multiline = false;
+
+                if (multiline || mlinebuf){
+                        size_t mlinebuf_length;
+                        if (mlinebuf)
+                                mlinebuf_length = strlen(mlinebuf);
+                        else
+                                mlinebuf_length = 0;
+
+                        char *tmp = malloc(mlinebuf_length+length+1); // + '\0'
+                        tmp[0]='\0'; // if mlinebuf_length==0 strncpy won't do anything. Make a null string.
+                        strncpy(tmp, mlinebuf, mlinebuf_length);
+                        tmp[mlinebuf_length]='\0'; // strncpy won't add '\0' at the end...
+                        strcat(tmp, line);
+                        if (mlinebuf)
+                                free(mlinebuf);
+                        free(line);
+                        mlinebuf = tmp;
+                        if (multiline) // The following line is part of a multi line config.
+                                continue;
+                        else {         // This is the last line of a multi line config.
+                                line = mlinebuf;
+                                sway_log(L_INFO, "Processing parsed multiline command '%s'", line);
+                                mlinebuf = NULL;
+                        }
+                }
+
                 struct cmd_results *res = config_command(line, block);
                 switch(res->status) {
                 case CMD_FAILURE:
diff --git a/sway/sway.5.txt b/sway/sway.5.txt
index bd2de12d..397b6d87 100644
--- a/sway/sway.5.txt
+++ b/sway/sway.5.txt
@@ -16,6 +16,12 @@ on startup.  These commands usually consist of setting your preferences and
 setting key bindings. An example config is likely present in /etc/sway/config
 for you to check out.
 
+Lines in the configuration file might be extended through multiple lines by
+adding a '\' character at the end of line. e.g.:
+
+        bindsym Shift+XF86AudioRaiseVolume exec pactl set-sink-volume \
+                $(pactl list sinks | grep -B 1 RUNNING | sed '1q;d' | sed 's/[^0-9]\+//g') +5%
+
 These commands can be executed in your config file, via **sway-msg**(1), or via
 the bindsym command.