CronTab.vala

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/*
 * CronTab.vala
 *
 * Copyright 2012-2018 Tony George <teejeetech@gmail.com>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 *
 *
 */
 
using TeeJee.Logging;
using TeeJee.FileSystem;
using TeeJee.ProcessHelper;
using TeeJee.Misc;
 
public class CronTab : GLib.Object {
 
    public static string crontab_text = null;
 
    public static void clear_cached_text(){
        crontab_text = null;
    }
    
    public static string crontab_read_all(string user_name = ""){
        string std_out, std_err;
 
        var cmd = "crontab -l";
        if (user_name.length > 0){
            cmd += " -u %s".printf(user_name);
        }
 
        log_debug(cmd);
        
        int ret_val = exec_sync(cmd, out std_out, out std_err);
        
        if (ret_val != 0){
            log_debug(_("Failed to read cron tab"));
            return "";
        }
        else{
            return std_out;
        }
    }
 
    public static bool has_job(string entry, bool partial_match, bool use_cached_text){
        
        // read crontab file
        string tab = "";
        if (use_cached_text && (crontab_text != null)){
            tab = crontab_text;
        }
        else{
            crontab_text = crontab_read_all();
            tab = crontab_text;
        }
 
        var lines = new Gee.ArrayList<string>();
        foreach(string line in tab.split("\n")){
            lines.add(line);
        }
 
        // check if entry exists
        foreach(string line in lines){
            if (line == entry){
                return true; // return
            }
            else if (partial_match && line.contains(entry)){
                return true; // return
            }
        }
 
        return false;
    }
    
    public static bool add_job(string entry, bool use_cached_text){
        
        // read crontab file
        string tab = "";
        if (use_cached_text && (crontab_text != null)){
            tab = crontab_text;
        }
        else{
            crontab_text = crontab_read_all();
            tab = crontab_text;
        }
        
        var lines = new Gee.ArrayList<string>();
        foreach(string line in tab.split("\n")){
            lines.add(line);
        }
 
        // check if entry exists
        foreach(string line in lines){
            if (line == entry){
                return true; // return
            }
        }
 
        // append entry
        lines.add(entry);
 
        // create new tab
        string tab_new = "";
        foreach(string line in lines){
            if (line.length > 0){
                tab_new += "%s\n".printf(line);
            }
        }
 
        // write temp crontab file
        string temp_file = get_temp_file_path();
        file_write(temp_file, tab_new);
 
        // install crontab file
        var cmd = "crontab \"%s\"".printf(temp_file);
        int status = exec_sync(cmd);
 
        if (status != 0){
            log_error(_("Failed to add cron job") + ": %s".printf(entry));
            return false;
        }
        else{
            log_msg(_("Cron job added") + ": %s".printf(entry));
            return true;
        }
    }
 
    public static bool remove_job(string entry, bool use_regex, bool use_cached_text){
        
        // read crontab file
        string tab = "";
        if (use_cached_text && (crontab_text != null)){
            tab = crontab_text;
        }
        else{
            crontab_text = crontab_read_all();
            tab = crontab_text;
        }
        
        var lines = new Gee.ArrayList<string>();
        foreach(string line in tab.split("\n")){
            lines.add(line);
        }
        
        Regex regex = null;
 
        if (use_regex){
            try {
                regex = new Regex(entry);
            }
            catch (Error e) {
                log_error (e.message);
            }
        }
 
        // check if entry exists
        bool found = false;
        for(int i=0; i < lines.size; i++){
            string line = lines[i];
            if (line != null){
                line = line.strip();
            }
 
            if (use_regex && (regex != null)){
                
                MatchInfo match;
                if (regex.match(line, 0, out match)) {
                    lines.remove(line);
                    found = true;
                }
            }
            else{
                if (line == entry){
                    lines.remove(line);
                    found = true;
                }
            }
        }
        if (!found){
            return true;
        }
 
        // create new tab
        string tab_new = "";
        foreach(string line in lines){
            if (line.length > 0){
                tab_new += "%s\n".printf(line);
            }
        }
 
        // write temp crontab file
        string temp_file = get_temp_file_path();
        file_write(temp_file, tab_new);
 
        // install crontab file
        var cmd = "crontab \"%s\"".printf(temp_file);
        int status = exec_sync(cmd);
 
        if (status != 0){
            log_error(_("Failed to remove cron job") + ": %s".printf(entry));
            return false;
        }
        else{
            log_msg(_("Cron job removed") + ": %s".printf(entry));
            return true;
        }
    }
 
    public static bool install(string file_path, string user_name = ""){
 
        if (!file_exists(file_path)){
            log_error(_("File not found") + ": %s".printf(file_path));
            return false;
        }
        
        var cmd = "crontab";
        if (user_name.length > 0){
            cmd += " -u %s".printf(user_name);
        }
        cmd += " \"%s\"".printf(file_path);
 
        log_debug(cmd);
 
        int status = exec_sync(cmd);
 
        if (status != 0){
            log_error(_("Failed to install crontab file") + ": %s".printf(file_path));
            return false;
        }
        else{
            log_msg(_("crontab file installed") + ": %s".printf(file_path));
            return true;
        }
    }
    
    public static bool export(string file_path, string user_name = ""){
        if (file_exists(file_path)){
            file_delete(file_path);
        }
        
        bool ok = file_write(file_path, crontab_read_all(user_name));
 
        if (!ok){
            log_error(_("Failed to export crontab file") + ": %s".printf(file_path));
            return false;
        }
        else{
            log_msg(_("crontab file exported") + ": %s".printf(file_path));
            return true;
        }
    }
 
    public static bool import(string file_path, string user_name = ""){
        return install(file_path, user_name);
    }
 
    public static bool add_script_file(string file_name, string cron_dir_type, string text, bool stop_cron_emails){
        
        /* Note:
         * cron.d and cron.hourly are managed by cron so it expects entries in crontab format
         * minute hour day_of_month month day_of_week user command
         * 
         * cron.{daily|weekly|monthly} are read by anacron. scripts placed here should have commands only.
         * */
 
        switch (cron_dir_type){
        case "d":
        case "hourly":
        case "daily":
        case "weekly":
        case "monthly":
            break;
        default:
            log_error("Cron directory type parameter not valid" + ": %s".printf(cron_dir_type));
            log_error("Expected values: d, hourly, daily, weekly, monthly");
            return false;
        }
 
        string file_path = "/etc/cron.%s/%s".printf(cron_dir_type, file_name.replace(".","-")); // dot is not allowed in file name
 
        string sh = "";
        sh += "SHELL=/bin/bash" + "\n";
        sh += "PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin" + "\n";
        if (stop_cron_emails){
            sh += "MAILTO=\"\"" + "\n";
        }
        sh += "\n";
        sh += text + "\n";
 
        if (file_exists(file_path) && (file_read(file_path) == sh)){
            log_debug(_("Cron task exists") + ": %s".printf(file_path));
            return true;
        }
 
        file_write(file_path, sh);
        Posix.chown(file_path, 0, 0); // chown to root:root
        Posix.chmod(file_path, 0644);
 
        log_msg(_("Added cron task") + ": %s".printf(file_path));
        
        return true;
    }
 
    public static bool remove_script_file(string file_name, string cron_dir_type){
 
        switch (cron_dir_type){
        case "d":
        case "hourly":
        case "daily":
        case "weekly":
        case "monthly":
            break;
        default:
            log_error("Cron directory type parameter not valid" + ": %s".printf(cron_dir_type));
            log_error("Expected values: d, hourly, daily, weekly, monthly");
            return false;
        }
 
        string file_path = "/etc/cron.%s/%s".printf(cron_dir_type, file_name.replace(".","-")); // dot is not allowed in file name
 
        if (!file_exists(file_path)){
            return true;
        }
        
        file_delete(file_path);
 
        log_msg(_("Removed cron task") + ": %s".printf(file_path));
        
        return true;
    }
}