/* Provides a functions for working with shell. Copyright (C) 2006-2022 Free Software Foundation, Inc. Written by: Slava Zanko , 2015. This file is part of the Midnight Commander. The Midnight Commander is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. The Midnight Commander is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ /** \file shell.c * \brief Source: provides a functions for working with shell. */ #include #include /* for username in xterm title */ #include #include #include #include "global.h" #include "util.h" /*** global variables ****************************************************************************/ /*** file scope macro definitions ****************************************************************/ /*** file scope type declarations ****************************************************************/ /*** file scope variables ************************************************************************/ static char rp_shell[PATH_MAX]; /*** file scope functions ************************************************************************/ /* --------------------------------------------------------------------------------------------- */ /** * Get a system shell. * * @return newly allocated mc_shell_t object with shell name */ static mc_shell_t * mc_shell_get_installed_in_system (void) { mc_shell_t *mc_shell; mc_shell = g_new0 (mc_shell_t, 1); /* 3rd choice: look for existing shells supported as MC subshells. */ if (access ("/bin/bash", X_OK) == 0) mc_shell->path = g_strdup ("/bin/bash"); else if (access ("/bin/ash", X_OK) == 0) mc_shell->path = g_strdup ("/bin/ash"); else if (access ("/bin/dash", X_OK) == 0) mc_shell->path = g_strdup ("/bin/dash"); else if (access ("/bin/busybox", X_OK) == 0) mc_shell->path = g_strdup ("/bin/busybox"); else if (access ("/bin/zsh", X_OK) == 0) mc_shell->path = g_strdup ("/bin/zsh"); else if (access ("/bin/tcsh", X_OK) == 0) mc_shell->path = g_strdup ("/bin/tcsh"); else if (access ("/bin/csh", X_OK) == 0) mc_shell->path = g_strdup ("/bin/csh"); /* 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 */ mc_shell->path = g_strdup ("/bin/sh"); return mc_shell; } /* --------------------------------------------------------------------------------------------- */ static char * mc_shell_get_name_env (void) { const char *shell_env; char *shell_name = NULL; shell_env = g_getenv ("SHELL"); if ((shell_env == NULL) || (shell_env[0] == '\0')) { /* 2nd choice: user login shell */ struct passwd *pwd; pwd = getpwuid (geteuid ()); if (pwd != NULL) shell_name = g_strdup (pwd->pw_shell); } else /* 1st choice: SHELL environment variable */ shell_name = g_strdup (shell_env); return shell_name; } /* --------------------------------------------------------------------------------------------- */ static mc_shell_t * mc_shell_get_from_env (void) { mc_shell_t *mc_shell = NULL; char *shell_name; shell_name = mc_shell_get_name_env (); if (shell_name != NULL) { mc_shell = g_new0 (mc_shell_t, 1); mc_shell->path = shell_name; } return mc_shell; } /* --------------------------------------------------------------------------------------------- */ static void mc_shell_recognize_real_path (mc_shell_t * mc_shell) { if (strstr (mc_shell->path, "/zsh") != NULL || strstr (mc_shell->real_path, "/zsh") != NULL || getenv ("ZSH_VERSION") != NULL) { /* Also detects ksh symlinked to zsh */ mc_shell->type = SHELL_ZSH; mc_shell->name = "zsh"; } else if (strstr (mc_shell->path, "/tcsh") != NULL || strstr (mc_shell->real_path, "/tcsh") != NULL) { /* Also detects csh symlinked to tcsh */ mc_shell->type = SHELL_TCSH; mc_shell->name = "tcsh"; } else if (strstr (mc_shell->path, "/csh") != NULL || strstr (mc_shell->real_path, "/csh") != NULL) { mc_shell->type = SHELL_TCSH; mc_shell->name = "csh"; } else if (strstr (mc_shell->path, "/fish") != NULL || strstr (mc_shell->real_path, "/fish") != NULL) { mc_shell->type = SHELL_FISH; mc_shell->name = "fish"; } else if (strstr (mc_shell->path, "/dash") != NULL || strstr (mc_shell->real_path, "/dash") != NULL) { /* Debian ash (also found if symlinked to by ash/sh) */ mc_shell->type = SHELL_DASH; mc_shell->name = "dash"; } else if (strstr (mc_shell->real_path, "/busybox") != NULL) { /* 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. */ mc_shell->type = SHELL_ASH_BUSYBOX; mc_shell->name = mc_shell->path; } else mc_shell->type = SHELL_NONE; } /* --------------------------------------------------------------------------------------------- */ static void mc_shell_recognize_path (mc_shell_t * mc_shell) { /* If shell is not symlinked to busybox, it is safe to assume it is a real shell */ if (strstr (mc_shell->path, "/bash") != NULL || getenv ("BASH") != NULL) { mc_shell->type = SHELL_BASH; mc_shell->name = "bash"; } else if (strstr (mc_shell->path, "/sh") != NULL || getenv ("SH") != NULL) { mc_shell->type = SHELL_SH; mc_shell->name = "sh"; } else if (strstr (mc_shell->path, "/ash") != NULL || getenv ("ASH") != NULL) { mc_shell->type = SHELL_ASH_BUSYBOX; mc_shell->name = "ash"; } else mc_shell->type = SHELL_NONE; } /* --------------------------------------------------------------------------------------------- */ /*** public functions ****************************************************************************/ /* --------------------------------------------------------------------------------------------- */ void mc_shell_init (void) { mc_shell_t *mc_shell; mc_shell = mc_shell_get_from_env (); if (mc_shell == NULL) mc_shell = mc_shell_get_installed_in_system (); mc_shell->real_path = mc_realpath (mc_shell->path, rp_shell); /* 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 (mc_shell->real_path != NULL) mc_shell_recognize_real_path (mc_shell); if (mc_shell->type == SHELL_NONE) mc_shell_recognize_path (mc_shell); if (mc_shell->type == SHELL_NONE) mc_global.tty.use_subshell = FALSE; mc_global.shell = mc_shell; } /* --------------------------------------------------------------------------------------------- */ void mc_shell_deinit (void) { if (mc_global.shell != NULL) { g_free (mc_global.shell->path); MC_PTR_FREE (mc_global.shell); } } /* --------------------------------------------------------------------------------------------- */