slave: exec shell from conf

main.c

@@ -548,7 +548,7 @@ main(int argc, char *const *argv)
 
     case 0:
         /* Child */
-        slave_spawn(term.ptmx);
+        slave_spawn(term.ptmx, conf.shell);
         assert(false);
         break;
 

slave.c

@@ -12,12 +12,95 @@
 #define LOG_ENABLE_DBG 0
 #include "log.h"
 
+static bool
+push_argv(char ***argv, size_t *size, char *arg, size_t *argc)
+{
+    if (arg != NULL && arg[0] == '%')
+        return true;
+
+    if (*argc >= *size) {
+        size_t new_size = *size > 0 ? 2 * *size : 10;
+        char **new_argv = realloc(*argv, new_size * sizeof(new_argv[0]));
+
+        if (new_argv == NULL)
+            return false;
+
+        *argv = new_argv;
+        *size = new_size;
+    }
+
+    (*argv)[(*argc)++] = arg;
+    return true;
+}
+
+static bool
+tokenize_cmdline(char *cmdline, char ***argv)
+{
+    *argv = NULL;
+    size_t argv_size = 0;
+
+    bool first_token_is_quoted = cmdline[0] == '"' || cmdline[0] == '\'';
+    char delim = first_token_is_quoted ? cmdline[0] : ' ';
+
+    char *p = first_token_is_quoted ? &cmdline[1] : &cmdline[0];
+
+    size_t idx = 0;
+    while (*p != '\0') {
+        char *end = strchr(p, delim);
+        if (end == NULL) {
+            if (delim != ' ') {
+                LOG_ERR("unterminated %s quote\n", delim == '"' ? "double" : "single");
+                free(*argv);
+                return false;
+            }
+
+            if (!push_argv(argv, &argv_size, p, &idx) ||
+                !push_argv(argv, &argv_size, NULL, &idx))
+            {
+                goto err;
+            } else
+                return true;
+        }
+
+        *end = '\0';
+
+        if (!push_argv(argv, &argv_size, p, &idx))
+            goto err;
+
+        p = end + 1;
+        while (*p == delim)
+            p++;
+
+        while (*p == ' ')
+            p++;
+
+        if (*p == '"' || *p == '\'') {
+            delim = *p;
+            p++;
+        } else
+            delim = ' ';
+    }
+
+    if (!push_argv(argv, &argv_size, NULL, &idx))
+        goto err;
+
+    return true;
+
+err:
+    free(*argv);
+    return false;
+}
+
 void
-slave_spawn(int ptmx)
+slave_spawn(int ptmx, char *cmd)
 {
     int pts = -1;
     const char *pts_name = ptsname(ptmx);
 
+    char **argv = NULL;
+    if (!tokenize_cmdline(cmd, &argv))
+        goto err;
+
     if (grantpt(ptmx) == -1) {
         LOG_ERRNO("failed to grantpt()");
         goto err;
@@ -52,9 +135,11 @@ slave_spawn(int ptmx)
     close(pts);
     pts = -1;
 
-    execl("/usr/bin/zsh", "/usr/bin/zsh", NULL);
+    execvp(argv[0], argv);
 
 err:
+    if (argv)
+        free(argv);
     if (pts != -1)
         close(pts);
     if (ptmx != -1)

slave.h

@@ -1,4 +1,4 @@
 #pragma once
 #include <stdbool.h>
 
-void slave_spawn(int ptmx);
+void slave_spawn(int ptmx, char *cmd);