mc: add ash subshell support

* backport a slightly modified subshell patch to stable 4.8.15
  (see ticket: https://www.midnight-commander.org/ticket/2742)
* enable subshell support by default

Signed-off-by: Dirk Brenken <dirk@brenken.org>
This commit is contained in:
Dirk Brenken 2015-11-25 20:15:36 +01:00
parent 46d99ac2f4
commit 1d797c29b0
3 changed files with 582 additions and 3 deletions

View File

@ -17,10 +17,10 @@ config MC_EDITOR
config MC_SUBSHELL
bool "Enable concurrent subshell"
default n
default y
help
This option enables concurrent subshell support.
Disabled by default.
Enabled by default.
config MC_LARGEFILE
bool "Enable largefile support"

View File

@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
PKG_NAME:=mc
PKG_VERSION:=4.8.15
PKG_RELEASE:=1
PKG_RELEASE:=2
PKG_MAINTAINER:=Dirk Brenken <dirk@brenken.org>
PKG_LICENSE:=GPL-3.0+

View File

@ -0,0 +1,579 @@
--- a/lib/global.c
+++ b/lib/global.c
@@ -97,6 +97,7 @@ mc_global_t mc_global = {
#endif /* !ENABLE_SUBSHELL */
.shell = NULL,
+ .shell_realpath = NULL,
.xterm_flag = FALSE,
.disable_x11 = FALSE,
--- a/lib/global.h
+++ b/lib/global.h
@@ -255,6 +255,7 @@ typedef struct
/* The user's shell */
char *shell;
+ char *shell_realpath;
/* This flag is set by xterm detection routine in function main() */
/* It is used by function view_other_cmd() */
--- a/lib/mcconfig/paths.c
+++ b/lib/mcconfig/paths.c
@@ -84,6 +84,7 @@ static const struct
/* data */
{ "skins", &mc_data_str, MC_SKINS_SUBDIR},
{ "fish", &mc_data_str, FISH_PREFIX},
+ { "ashrc", &mc_data_str, "ashrc"},
{ "bashrc", &mc_data_str, "bashrc"},
{ "inputrc", &mc_data_str, "inputrc"},
{ "extfs.d", &mc_data_str, MC_EXTFS_DIR},
--- a/src/main.c
+++ b/src/main.c
@@ -87,6 +87,9 @@
/*** file scope variables ************************************************************************/
/*** file scope functions ************************************************************************/
+
+static char rp_shell[PATH_MAX];
+
/* --------------------------------------------------------------------------------------------- */
static void
@@ -118,6 +121,44 @@ check_codeset (void)
}
/* --------------------------------------------------------------------------------------------- */
+/**
+ * Get a system shell.
+ *
+ * @return newly allocated string with shell name
+ */
+
+static char *
+mc_get_system_shell (void)
+{
+ char *sh_str;
+ /* 3rd choice: look for existing shells supported as MC subshells. */
+ if (access ("/bin/bash", X_OK) == 0)
+ sh_str = g_strdup ("/bin/bash");
+ else if (access ("/bin/ash", X_OK) == 0)
+ sh_str = g_strdup ("/bin/ash");
+ else if (access ("/bin/dash", X_OK) == 0)
+ sh_str = g_strdup ("/bin/dash");
+ else if (access ("/bin/busybox", X_OK) == 0)
+ sh_str = g_strdup ("/bin/busybox");
+ else if (access ("/bin/zsh", X_OK) == 0)
+ sh_str = g_strdup ("/bin/zsh");
+ else if (access ("/bin/tcsh", X_OK) == 0)
+ sh_str = g_strdup ("/bin/tcsh");
+ /* 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
+ * will not use a subshell but just a command line.
+ * else if (access("/bin/fish", X_OK) == 0)
+ * mc_global.tty.shell = g_strdup ("/bin/fish");
+ */
+ else
+ /* Fallback and last resort: system default shell */
+ sh_str = g_strdup ("/bin/sh");
+
+ return sh_str;
+}
+
+/* --------------------------------------------------------------------------------------------- */
/** POSIX version. The only version we support. */
static void
@@ -126,9 +167,11 @@ OS_Setup (void)
const char *shell_env;
const char *datadir_env;
+
shell_env = getenv ("SHELL");
if ((shell_env == NULL) || (shell_env[0] == '\0'))
{
+ /* 2nd choice: user login shell */
struct passwd *pwd;
pwd = getpwuid (geteuid ());
@@ -136,13 +179,15 @@ OS_Setup (void)
mc_global.tty.shell = g_strdup (pwd->pw_shell);
}
else
+ /* 1st choice: SHELL environment variable */
mc_global.tty.shell = g_strdup (shell_env);
if ((mc_global.tty.shell == NULL) || (mc_global.tty.shell[0] == '\0'))
{
g_free (mc_global.tty.shell);
- mc_global.tty.shell = g_strdup ("/bin/sh");
+ mc_global.tty.shell = mc_get_system_shell ();
}
+ mc_global.tty.shell_realpath = mc_realpath (mc_global.tty.shell, rp_shell);
/* This is the directory, where MC was installed, on Unix this is DATADIR */
/* and can be overriden by the MC_DATADIR environment variable */
--- a/src/subshell.c
+++ b/src/subshell.c
@@ -114,6 +114,8 @@ enum
static enum
{
BASH,
+ ASH_BUSYBOX, /* BusyBox default shell (ash) */
+ DASH, /* Debian variant of ash */
TCSH,
ZSH,
FISH
@@ -209,6 +211,7 @@ static void
init_subshell_child (const char *pty_name)
{
char *init_file = NULL;
+ char *putenv_str = NULL;
pid_t mc_sid;
(void) pty_name;
@@ -257,32 +260,53 @@ init_subshell_child (const char *pty_nam
switch (subshell_type)
{
case BASH:
+ /* Do we have a custom init file ~/.local/share/mc/bashrc? */
init_file = mc_config_get_full_path ("bashrc");
+ /* Otherwise use ~/.bashrc */
if (access (init_file, R_OK) == -1)
{
g_free (init_file);
init_file = g_strdup (".bashrc");
}
- /* Make MC's special commands not show up in bash's history */
- putenv ((char *) "HISTCONTROL=ignorespace");
+ /* Make MC's special commands not show up in bash's history and also suppress
+ * consecutive identical commands*/
+ putenv ((char *) "HISTCONTROL=ignoreboth");
/* Allow alternative readline settings for MC */
{
char *input_file = mc_config_get_full_path ("inputrc");
if (access (input_file, R_OK) == 0)
{
- char *putenv_str = g_strconcat ("INPUTRC=", input_file, NULL);
+ putenv_str = g_strconcat ("INPUTRC=", input_file, NULL);
putenv (putenv_str);
- g_free (putenv_str);
}
g_free (input_file);
}
break;
- /* TODO: Find a way to pass initfile to TCSH and ZSH */
+ case ASH_BUSYBOX:
+ case DASH:
+ /* Do we have a custom init file ~/.local/share/mc/ashrc? */
+ init_file = mc_config_get_full_path ("ashrc");
+
+ /* Otherwise use ~/.profile */
+ if (access (init_file, R_OK) == -1)
+ {
+ g_free (init_file);
+ init_file = g_strdup (".profile");
+ }
+
+ /* Put init file to ENV variable used by ash */
+ putenv_str = g_strconcat ("ENV=", init_file, NULL);
+ putenv (putenv_str);
+ /* Do not use "g_free (putenv_str)" here, otherwise ENV will be undefined! */
+
+ break;
+
+ /* TODO: Find a way to pass initfile to TCSH, ZSH and FISH */
case TCSH:
case ZSH:
case FISH:
@@ -320,10 +344,6 @@ init_subshell_child (const char *pty_nam
execl (mc_global.tty.shell, "bash", "-rcfile", init_file, (char *) NULL);
break;
- case TCSH:
- execl (mc_global.tty.shell, "tcsh", (char *) NULL);
- break;
-
case ZSH:
/* Use -g to exclude cmds beginning with space from history
* and -Z to use the line editor on non-interactive term */
@@ -331,8 +351,11 @@ init_subshell_child (const char *pty_nam
break;
+ case ASH_BUSYBOX:
+ case DASH:
+ case TCSH:
case FISH:
- execl (mc_global.tty.shell, "fish", (char *) NULL);
+ execl (mc_global.tty.shell, mc_global.tty.shell, (char *) NULL);
break;
default:
@@ -341,6 +364,7 @@ init_subshell_child (const char *pty_nam
/* If we get this far, everything failed miserably */
g_free (init_file);
+ g_free (putenv_str);
my_exit (FORK_FAILURE);
}
@@ -742,6 +766,171 @@ pty_open_slave (const char *pty_name)
}
#endif /* !HAVE_GRANTPT */
+
+/* --------------------------------------------------------------------------------------------- */
+/**
+ * Get a subshell type and store in subshell_type variable
+ *
+ * @return TRUE if subtype was gotten, FALSE otherwise
+ */
+
+static gboolean
+init_subshell_type (void)
+{
+ gboolean result = TRUE;
+
+ /* Find out what type of shell we have. Also consider real paths (resolved symlinks)
+ * because e.g. csh might point to tcsh, ash to dash or busybox, sh to anything. */
+
+ if (strstr (mc_global.tty.shell, "/zsh") || strstr (mc_global.tty.shell_realpath, "/zsh")
+ || getenv ("ZSH_VERSION"))
+ /* Also detects ksh symlinked to zsh */
+ subshell_type = ZSH;
+ else if (strstr (mc_global.tty.shell, "/tcsh")
+ || strstr (mc_global.tty.shell_realpath, "/tcsh"))
+ /* Also detects csh symlinked to tcsh */
+ subshell_type = TCSH;
+ else if (strstr (mc_global.tty.shell, "/fish")
+ || strstr (mc_global.tty.shell_realpath, "/fish"))
+ subshell_type = FISH;
+ else if (strstr (mc_global.tty.shell, "/dash")
+ || strstr (mc_global.tty.shell_realpath, "/dash"))
+ /* Debian ash (also found if symlinked to by ash/sh) */
+ subshell_type = DASH;
+ else if (strstr (mc_global.tty.shell_realpath, "/busybox"))
+ {
+ /* If shell is symlinked to busybox, assume it is an ash, even though theoretically
+ * it could also be a hush (a mini shell for non-MMU systems deactivated by default).
+ * For simplicity's sake we assume that busybox always contains an ash, not a hush.
+ * On embedded platforms or on server systems, /bin/sh often points to busybox.
+ * Sometimes even bash is symlinked to busybox (CONFIG_FEATURE_BASH_IS_ASH option),
+ * so we need to check busybox symlinks *before* checking for the name "bash"
+ * in order to avoid that case. */
+ subshell_type = ASH_BUSYBOX;
+ }
+ else if (strstr (mc_global.tty.shell, "/bash") || getenv ("BASH"))
+ /* If bash is not symlinked to busybox, it is safe to assume it is a real bash */
+ subshell_type = BASH;
+ else
+ {
+ mc_global.tty.use_subshell = FALSE;
+ result = FALSE;
+ }
+ return result;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+/**
+ * Set up `precmd' or equivalent for reading the subshell's CWD.
+ *
+ * Attention! Never forget that these are *one-liners* even though the concatenated
+ * substrings contain line breaks and indentation for better understanding of the
+ * shell code. It is vital that each one-liner ends with a line feed character ("\n" ).
+ *
+ * @return initialized pre-command string
+ */
+
+static void
+init_subshell_precmd (char *precmd, size_t buff_size)
+{
+
+ switch (subshell_type)
+ {
+ case BASH:
+ g_snprintf (precmd, buff_size,
+ " PROMPT_COMMAND='pwd>&%d; kill -STOP $$';\n", subshell_pipe[WRITE]);
+ break;
+
+ case ASH_BUSYBOX:
+ /* BusyBox ash needs a somewhat complicated precmd emulation via PS1, and it is vital
+ * that BB be built with active CONFIG_ASH_EXPAND_PRMT, but this is the default anyway.
+ *
+ * A: This leads to a stopped subshell (=frozen mc) if user calls "ash" command
+ * "PS1='$(pwd>&%d; kill -STOP $$)\\u@\\h:\\w\\$ '\n",
+ *
+ * B: This leads to "sh: precmd: not found" in sub-subshell if user calls "ash" command
+ * "precmd() { pwd>&%d; kill -STOP $$; }; "
+ * "PS1='$(precmd)\\u@\\h:\\w\\$ '\n",
+ *
+ * C: This works if user calls "ash" command because in sub-subshell
+ * PRECMD is unfedined, thus evaluated to empty string - no damage done.
+ * Attention: BusyBox must be built with FEATURE_EDITING_FANCY_PROMPT to
+ * permit \u, \w, \h, \$ escape sequences. Unfortunately this cannot be guaranteed,
+ * especially on embedded systems where people try to save space, so let's use
+ * the dash version below. It should work on virtually all systems.
+ * "precmd() { pwd>&%d; kill -STOP $$; }; "
+ * "PRECMD=precmd; "
+ * "PS1='$(eval $PRECMD)\\u@\\h:\\w\\$ '\n",
+ */
+ case DASH:
+ /* Debian ash needs a precmd emulation via PS1, similar to BusyBox ash,
+ * but does not support escape sequences for user, host and cwd in prompt.
+ * Attention! Make sure that the buffer for precmd is big enough.
+ *
+ * We want to have a fancy dynamic prompt with user@host:cwd just like in the BusyBox
+ * examples above, but because replacing the home directory part of the path by "~" is
+ * complicated, it bloats the precmd to a size > BUF_SMALL (128).
+ *
+ * The following example is a little less fancy (home directory not replaced)
+ * and shows the basic workings of our prompt for easier understanding:
+ *
+ * "precmd() { "
+ * "echo \"$USER@$(hostname -s):$PWD\"; "
+ * "pwd>&%d; "
+ * "kill -STOP $$; "
+ * "}; "
+ * "PRECMD=precmd; "
+ * "PS1='$($PRECMD)$ '\n",
+ */
+ g_snprintf (precmd, buff_size,
+ "precmd() { "
+ "if [ ! \"${PWD##$HOME}\" ]; then "
+ "MC_PWD=\"~\"; "
+ "else "
+ "[ \"${PWD##$HOME/}\" = \"$PWD\" ] && MC_PWD=\"$PWD\" || MC_PWD=\"~/${PWD##$HOME/}\"; "
+ "fi; "
+ "echo \"$USER@openwrt:$MC_PWD\"; "
+ "pwd>&%d; "
+ "kill -STOP $$; "
+ "}; " "PRECMD=precmd; " "PS1='$($PRECMD)$ '\n", subshell_pipe[WRITE]);
+ break;
+
+ case ZSH:
+ g_snprintf (precmd, buff_size,
+ " precmd() { pwd>&%d; kill -STOP $$; }; "
+ "PS1='%%n@%%m:%%~%%# '\n", subshell_pipe[WRITE]);
+ break;
+
+ case TCSH:
+ g_snprintf (precmd, buff_size,
+ "set echo_style=both; "
+ "set prompt='%%n@%%m:%%~%%# '; "
+ "alias precmd 'echo $cwd:q >>%s; kill -STOP $$'\n", tcsh_fifo);
+ break;
+
+ case FISH:
+ /* We also want a fancy user@host:cwd prompt here, but fish makes it very easy to also
+ * use colours, which is what we will do. But first here is a simpler, uncoloured version:
+ * "function fish_prompt; "
+ * "echo (whoami)@(hostname -s):(pwd)\\$\\ ; "
+ * "echo \"$PWD\">&%d; "
+ * "kill -STOP %%self; "
+ * "end\n",
+ *
+ * TODO: fish prompt is shown when panel is hidden (Ctrl-O), but not when it is visible.
+ * Find out how to fix this.
+ */
+ g_snprintf (precmd, buff_size,
+ "function fish_prompt; "
+ "echo (whoami)@(hostname -s):(set_color $fish_color_cwd)(pwd)(set_color normal)\\$\\ ; "
+ "echo \"$PWD\">&%d; " "kill -STOP %%self; " "end\n", subshell_pipe[WRITE]);
+ break;
+
+ default:
+ break;
+ }
+}
+
/* --------------------------------------------------------------------------------------------- */
/*** public functions ****************************************************************************/
/* --------------------------------------------------------------------------------------------- */
@@ -761,6 +950,7 @@ init_subshell (void)
{
/* This must be remembered across calls to init_subshell() */
static char pty_name[BUF_SMALL];
+ /* Must be considerably longer than BUF_SMALL (128) to support fancy shell prompts */
char precmd[BUF_MEDIUM];
switch (check_sid ())
@@ -782,23 +972,8 @@ init_subshell (void)
if (mc_global.tty.subshell_pty == 0)
{ /* First time through */
- /* Find out what type of shell we have */
-
- if (strstr (mc_global.tty.shell, "/zsh") || getenv ("ZSH_VERSION"))
- subshell_type = ZSH;
- else if (strstr (mc_global.tty.shell, "/tcsh"))
- subshell_type = TCSH;
- else if (strstr (mc_global.tty.shell, "/csh"))
- subshell_type = TCSH;
- else if (strstr (mc_global.tty.shell, "/bash") || getenv ("BASH"))
- subshell_type = BASH;
- else if (strstr (mc_global.tty.shell, "/fish"))
- subshell_type = FISH;
- else
- {
- mc_global.tty.use_subshell = FALSE;
+ if (!init_subshell_type ())
return;
- }
/* Open a pty for talking to the subshell */
@@ -844,7 +1019,7 @@ init_subshell (void)
return;
}
}
- else /* subshell_type is BASH or ZSH */ if (pipe (subshell_pipe))
+ else if (pipe (subshell_pipe)) /* subshell_type is BASH, ASH_BUSYBOX, DASH or ZSH */
{
perror (__FILE__ ": couldn't create pipe");
mc_global.tty.use_subshell = FALSE;
@@ -872,39 +1047,116 @@ init_subshell (void)
init_subshell_child (pty_name);
}
- /* Set up 'precmd' or equivalent for reading the subshell's CWD */
+ init_subshell_precmd (precmd, BUF_MEDIUM);
+
+ /* Set up `precmd' or equivalent for reading the subshell's CWD
+ *
+ * Attention! Never forget that these are *one-liners* even though the concatenated
+ * substrings contain line breaks and indentation for better understanding of the
+ * shell code. It is vital that each one-liner ends with a line feed character ("\n" ).
+ */
switch (subshell_type)
{
case BASH:
g_snprintf (precmd, sizeof (precmd),
- " PROMPT_COMMAND=${PROMPT_COMMAND:+$PROMPT_COMMAND\n}'pwd>&%d;kill -STOP $$'\n",
- subshell_pipe[WRITE]);
+ " PROMPT_COMMAND=${PROMPT_COMMAND:+$PROMPT_COMMAND\n}'pwd>&%d;kill -STOP $$'\n"
+ "PS1='\\u@\\h:\\w\\$ '\n", subshell_pipe[WRITE]);
+ break;
+
+ case ASH_BUSYBOX:
+ /* BusyBox ash needs a somewhat complicated precmd emulation via PS1, and it is vital
+ * that BB be built with active CONFIG_ASH_EXPAND_PRMT, but this is the default anyway.
+ *
+ * A: This leads to a stopped subshell (=frozen mc) if user calls "ash" command
+ * "PS1='$(pwd>&%d; kill -STOP $$)\\u@\\h:\\w\\$ '\n",
+ *
+ * B: This leads to "sh: precmd: not found" in sub-subshell if user calls "ash" command
+ * "precmd() { pwd>&%d; kill -STOP $$; }; "
+ * "PS1='$(precmd)\\u@\\h:\\w\\$ '\n",
+ *
+ * C: This works if user calls "ash" command because in sub-subshell
+ * PRECMD is unfedined, thus evaluated to empty string - no damage done.
+ * Attention: BusyBox must be built with FEATURE_EDITING_FANCY_PROMPT to
+ * permit \u, \w, \h, \$ escape sequences. Unfortunately this cannot be guaranteed,
+ * especially on embedded systems where people try to save space, so let's use
+ * the dash version below. It should work on virtually all systems.
+ * "precmd() { pwd>&%d; kill -STOP $$; }; "
+ * "PRECMD=precmd; "
+ * "PS1='$(eval $PRECMD)\\u@\\h:\\w\\$ '\n",
+ */
+ case DASH:
+ /* Debian ash needs a precmd emulation via PS1, similar to BusyBox ash,
+ * but does not support escape sequences for user, host and cwd in prompt.
+ * Attention! Make sure that the buffer for precmd is big enough.
+ *
+ * We want to have a fancy dynamic prompt with user@host:cwd just like in the BusyBox
+ * examples above, but because replacing the home directory part of the path by "~" is
+ * complicated, it bloats the precmd to a size > BUF_SMALL (128).
+ *
+ * The following example is a little less fancy (home directory not replaced)
+ * and shows the basic workings of our prompt for easier understanding:
+ *
+ * "precmd() { "
+ * "echo \"$USER@$(hostname -s):$PWD\"; "
+ * "pwd>&%d; "
+ * "kill -STOP $$; "
+ * "}; "
+ * "PRECMD=precmd; "
+ * "PS1='$($PRECMD)$ '\n",
+ */
+ g_snprintf (precmd, sizeof (precmd),
+ "precmd() { "
+ "if [ ! \"${PWD##$HOME}\" ]; then "
+ "MC_PWD=\"~\"; "
+ "else "
+ "[ \"${PWD##$HOME/}\" = \"$PWD\" ] && MC_PWD=\"$PWD\" || MC_PWD=\"~/${PWD##$HOME/}\"; "
+ "fi; "
+ "echo \"$USER@openwrt:$MC_PWD\"; "
+ "pwd>&%d; "
+ "kill -STOP $$; "
+ "}; " "PRECMD=precmd; " "PS1='$($PRECMD)$ '\n", subshell_pipe[WRITE]);
break;
case ZSH:
g_snprintf (precmd, sizeof (precmd),
- " _mc_precmd(){ pwd>&%d;kill -STOP $$ }; precmd_functions+=(_mc_precmd)\n",
- subshell_pipe[WRITE]);
+ " _mc_precmd(){ pwd>&%d;kill -STOP $$ }; precmd_functions+=(_mc_precmd)\n"
+ "PS1='%%n@%%m:%%~%%# '\n", subshell_pipe[WRITE]);
break;
case TCSH:
g_snprintf (precmd, sizeof (precmd),
- "set echo_style=both;"
- "alias precmd 'echo $cwd:q >>%s;kill -STOP $$'\n", tcsh_fifo);
+ "set echo_style=both; "
+ "set prompt='%%n@%%m:%%~%%# '; "
+ "alias precmd 'echo $cwd:q >>%s; kill -STOP $$'\n", tcsh_fifo);
break;
+
case FISH:
/* Use fish_prompt_mc function for prompt, if not present then copy fish_prompt to it. */
+ /* We also want a fancy user@host:cwd prompt here, but fish makes it very easy to also
+ * use colours, which is what we will do. But first here is a simpler, uncoloured version:
+ * "function fish_prompt; "
+ * "echo (whoami)@(hostname -s):(pwd)\\$\\ ; "
+ * "echo \"$PWD\">&%d; "
+ * "kill -STOP %%self; "
+ * "end\n",
+ *
+ * TODO: fish prompt is shown when panel is hidden (Ctrl-O), but not when it is visible.
+ * Find out how to fix this.
+ */
g_snprintf (precmd, sizeof (precmd),
"if not functions -q fish_prompt_mc;"
"functions -c fish_prompt fish_prompt_mc; end;"
- "function fish_prompt; echo $PWD>&%d; fish_prompt_mc; kill -STOP %%self; end\n",
+ "function fish_prompt;"
+ "echo (whoami)@(hostname -s):(set_color $fish_color_cwd)(pwd)(set_color normal)\\$\\ ; "
+ "echo \"$PWD\">&%d; fish_prompt_mc; kill -STOP %%self; end\n",
subshell_pipe[WRITE]);
break;
default:
break;
}
+
write_all (mc_global.tty.subshell_pty, precmd, strlen (precmd));
/* Wait until the subshell has started up and processed the command */
@@ -1108,6 +1360,13 @@ subshell_name_quote (const char *s)
quote_cmd_start = "(printf \"%b\" '";
quote_cmd_end = "')";
}
+ /* TODO: When BusyBox printf is fixed, get rid of this "else if", see
+ http://lists.busybox.net/pipermail/busybox/2012-March/077460.html */
+ /* else if (subshell_type == ASH_BUSYBOX)
+ {
+ quote_cmd_start = "\"`echo -en '";
+ quote_cmd_end = "'`\"";
+ } */
else
{
quote_cmd_start = "\"`printf \"%b\" '";