Ticket #3748: add support for ksh in subshell

Support Korn shell variants (ksh/oksh/mksh) in the subshell.

doc/man/mc.1.in

@@ -2406,6 +2406,10 @@ and special keyboard maps in ~/.local/share/mc/inputrc (fallback ~/.inputrc).
 .B ash/dash
 users (BusyBox or Debian) may specify startup commands in ~/.local/share/mc/ashrc (fallback ~/.profile).
 .PP
+.B ksh
+users (ksh, oksh or mksh) may specify startup commands in ~/.local/share/mc/kshrc
+(fallback $ENV or ~/.profile).
+.PP
 .B zsh
 users may specify startup commands in ~/.local/share/mc/.zshrc (fallback ~/.zshrc).
 .PP

lib/fileloc.h

@@ -53,6 +53,7 @@
 #define MC_BASHRC_FILE          "bashrc"
 #define MC_ZSHRC_FILE           ".zshrc"
 #define MC_ASHRC_FILE           "ashrc"
+#define MC_KSHRC_FILE           "kshrc"
 #define MC_INPUTRC_FILE         "inputrc"
 #define MC_CONFIG_FILE          "ini"
 #define MC_EXT_FILE             "mc.ext.ini"

lib/mcconfig/paths.c

@@ -75,6 +75,7 @@ static const struct
     { &mc_data_str, MC_SKINS_DIR },
     { &mc_data_str, VFS_SHELL_PREFIX },
     { &mc_data_str, MC_ASHRC_FILE },
+    { &mc_data_str, MC_KSHRC_FILE },
     { &mc_data_str, MC_BASHRC_FILE },
     { &mc_data_str, MC_INPUTRC_FILE },
     { &mc_data_str, MC_ZSHRC_FILE },

lib/shell.c

@@ -80,6 +80,8 @@ mc_shell_get_installed_in_system (void)
         mc_shell->path = g_strdup ("/bin/tcsh");
     else if (access ("/bin/csh", X_OK) == 0)
         mc_shell->path = g_strdup ("/bin/csh");
+    else if (access ("/bin/ksh", X_OK) == 0)
+        mc_shell->path = g_strdup ("/bin/ksh");
     /* No fish as fallback because it is so much different from other shells and
      * in a way exotic (even though user-friendly by name) that we should not
      * present it as a subshell without the user's explicit intention. We rather
@@ -189,6 +191,17 @@ mc_shell_recognize_real_path (mc_shell_t *mc_shell)
         mc_shell->type = SHELL_ASH_BUSYBOX;
         mc_shell->name = mc_shell->path;
     }
+    else if (strstr (mc_shell->path, "/ksh") != NULL
+             || strstr (mc_shell->real_path, "/ksh") != NULL
+             || strstr (mc_shell->path, "/oksh") != NULL
+             || strstr (mc_shell->real_path, "/oksh") != NULL
+             || strstr (mc_shell->path, "/mksh") != NULL
+             || strstr (mc_shell->real_path, "/mksh") != NULL)
+    {
+        /* Korn shell variants */
+        mc_shell->type = SHELL_KSH;
+        mc_shell->name = "ksh";
+    }
     else
         mc_shell->type = SHELL_NONE;
 }
@@ -214,6 +227,14 @@ mc_shell_recognize_path (mc_shell_t *mc_shell)
         mc_shell->type = SHELL_ASH_BUSYBOX;
         mc_shell->name = "ash";
     }
+    else if (strstr (mc_shell->path, "/ksh") != NULL 
+             || strstr (mc_shell->path, "/oksh") != NULL
+             || strstr (mc_shell->path, "/mksh") != NULL
+             || getenv ("KSH_VERSION") != NULL)
+    {
+        mc_shell->type = SHELL_KSH;
+        mc_shell->name = "ksh";
+    }
     else
         mc_shell->type = SHELL_NONE;
 }

lib/shell.h

@@ -18,7 +18,8 @@ typedef enum
     SHELL_DASH,                 /* Debian variant of ash */
     SHELL_TCSH,
     SHELL_ZSH,
-    SHELL_FISH
+    SHELL_FISH,
+    SHELL_KSH
 } shell_type_t;
 
 /*** structures declarations (and typedefs of structures)*****************************************/

src/subshell/common.c

@@ -365,6 +365,33 @@ init_subshell_child (const char *pty_name)
 
         break;
 
+    case SHELL_KSH:
+        /* Do we have a custom init file ~/.local/share/mc/kshrc? */
+        init_file = mc_config_get_full_path (MC_KSHRC_FILE);
+
+        /* Otherwise use ~/.profile if $ENV is not already set */
+        if (!exist_file (init_file))
+        {
+            g_free (init_file);
+            init_file = NULL;
+
+            if (!g_getenv ("ENV"))
+            {
+                init_file = g_strdup (".profile");
+            }
+        }
+
+        /* Put init file to ENV variable used by ash */
+        if (init_file)
+        {
+            g_setenv ("ENV", init_file, TRUE);
+        }
+
+        /* Make MC's special commands not show up in history */
+        putenv ((char *) "HISTCONTROL=ignorespace");
+
+        break;
+
     case SHELL_ZSH:
         /* ZDOTDIR environment variable is the only way to point zsh
          * to an other rc file than the default. */
@@ -438,6 +465,7 @@ init_subshell_child (const char *pty_name)
     case SHELL_ASH_BUSYBOX:
     case SHELL_DASH:
     case SHELL_TCSH:
+    case SHELL_KSH:
         execl (mc_global.shell->path, mc_global.shell->path, (char *) NULL);
         break;
 
@@ -1163,6 +1191,12 @@ init_subshell_precmd (char *precmd, size_t buff_size)
                     "}; " "PRECMD=precmd; " "PS1='$($PRECMD)$ '\n", subshell_pipe[WRITE]);
         break;
 
+    case SHELL_KSH:
+        g_snprintf (precmd, buff_size,
+                    " PS1='$(pwd>&%d; kill -STOP $$)\\u@\\h:\\w\\$ '\n",
+                    subshell_pipe[WRITE]);
+       break;
+
     case SHELL_ZSH:
         g_snprintf (precmd, buff_size,
                     " mc_print_command_buffer () { printf \"%%s\\\\n\" \"$BUFFER\" >&%d; }\n"