vcs.maemo.org Git - monky/blob - src/tailhead.c

   1 /* -*- mode: c; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: t -*-
   2  * vim: ts=4 sw=4 noet ai cindent syntax=c
   3  *
   4  * Conky, a system monitor, based on torsmo
   5  *
   6  * Any original torsmo code is licensed under the BSD license
   7  *
   8  * All code written since the fork of torsmo is licensed under the GPL
   9  *
  10  * Please see COPYING for details
  11  *
  12  * Copyright (c) 2004, Hannu Saransaari and Lauri Hakkarainen
  13  * Copyright (c) 2005-2009 Brenden Matthews, Philip Kovacs, et. al.
  14  *      (see AUTHORS)
  15  * All rights reserved.
  16  *
  17  * This program is free software: you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation, either version 3 of the License, or
  20  * (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  28  *
  29  */
  30
  31 #include "text_object.h"
  32 #include "logging.h"
  33 #include <sys/stat.h>
  34 #include <fcntl.h>
  35 #include <unistd.h>
  36
  37 #define MAX_HEADTAIL_LINES 30
  38 #define DEFAULT_MAX_HEADTAIL_USES 2
  39
  40 void tailstring(char *string, int endofstring, int wantedlines) {
  41         int i, linescounted = 0;
  42
  43         string[endofstring] = 0;
  44         if(endofstring > 0) {
  45                 if(string[endofstring-1] == '\n') {     //work with or without \n at end of file
  46                         string[endofstring-1] = 0;
  47                 }
  48                 for(i = endofstring - 1; i >= 0 && linescounted < wantedlines; i--) {
  49                         if(string[i] == '\n') {
  50                                 linescounted++;
  51                         }
  52                 }
  53                 if(i > 0) {
  54                         strfold(string, i+2);
  55                 }
  56         }
  57 }
  58
  59 void init_tailhead(const char* type, const char* arg, struct text_object *obj, void* free_at_crash) {
  60         unsigned int args;
  61
  62         if(arg) {
  63                 obj->data.headtail.logfile=malloc(DEFAULT_TEXT_BUFFER_SIZE);
  64                 obj->data.headtail.max_uses = DEFAULT_MAX_HEADTAIL_USES;
  65                 args = sscanf(arg, "%s %d %d", obj->data.headtail.logfile, &obj->data.headtail.wantedlines, &obj->data.headtail.max_uses);
  66                 if(args == 2 || args == 3) {
  67                         if(obj->data.headtail.max_uses < 1) {
  68                                 free(obj->data.headtail.logfile);
  69                                 CRIT_ERR(obj, free_at_crash, "invalid arg for %s, next_check must be larger than 0", type);
  70                         }
  71                         if (obj->data.headtail.wantedlines > 0 && obj->data.headtail.wantedlines <= MAX_HEADTAIL_LINES) {
  72                                 to_real_path(obj->data.headtail.logfile, obj->data.headtail.logfile);
  73                                 obj->data.headtail.buffer = NULL;
  74                                 obj->data.headtail.current_use = 0;
  75                         }else{
  76                                 free(obj->data.headtail.logfile);
  77                                 CRIT_ERR(obj, free_at_crash, "invalid arg for %s, number of lines must be between 1 and %d", type, MAX_HEADTAIL_LINES);
  78                         }
  79                 } else {
  80                         free(obj->data.headtail.logfile);
  81                         CRIT_ERR(obj, free_at_crash, "%s needs a file as 1st and a number of lines as 2nd argument", type);
  82                 }
  83         } else {
  84                 CRIT_ERR(obj, free_at_crash, "%s needs arguments", type);
  85         }
  86 }
  87
  88 void print_tailhead(const char* type, struct text_object *obj, char *p, int p_max_size) {
  89         int fd, i, endofstring = 0, linescounted = 0;
  90         FILE *fp;
  91         struct stat st;
  92
  93         //empty the buffer and reset the counter if we used it the max number of times
  94         if(obj->data.headtail.buffer && obj->data.headtail.current_use >= obj->data.headtail.max_uses - 1) {
  95                 free(obj->data.headtail.buffer);
  96                 obj->data.headtail.buffer = NULL;
  97                 obj->data.headtail.current_use = 0;
  98         }
  99         //use the buffer if possible
 100         if(obj->data.headtail.buffer) {
 101                 strcpy(p, obj->data.headtail.buffer);
 102                 obj->data.headtail.current_use++;
 103         }else{  //otherwise find the needed data
 104                 if(stat(obj->data.headtail.logfile, &st) == 0) {
 105                         if (S_ISFIFO(st.st_mode)) {
 106                                 fd = open_fifo(obj->data.headtail.logfile, &obj->a);
 107                                 if(fd != -1) {
 108                                         if(strcmp(type, "head") == 0) {
 109                                                 for(i = 0; linescounted < obj->data.headtail.wantedlines; i++) {
 110                                                         read(fd, p + i, 1);
 111                                                         if(p[i] == '\n') {
 112                                                                 linescounted++;
 113                                                         }
 114                                                 }
 115                                                 p[i] = 0;
 116                                         } else if(strcmp(type, "tail") == 0) {
 117                                                 i = read(fd, p, p_max_size - 1);
 118                                                 tailstring(p, i, obj->data.headtail.wantedlines);
 119                                         } else {
 120                                                 CRIT_ERR(NULL, NULL, "If you are seeing this then there is a bug in the code, report it !");
 121                                         }
 122                                 }
 123                                 close(fd);
 124                         } else {
 125                                 fp = open_file(obj->data.headtail.logfile, &obj->a);
 126                                 if(fp != NULL) {
 127                                         if(strcmp(type, "head") == 0) {
 128                                                 for(i = 0; i < obj->data.headtail.wantedlines; i++) {
 129                                                         fgets(p + endofstring, p_max_size - endofstring, fp);
 130                                                         endofstring = strlen(p);
 131                                                 }
 132                                         } else if(strcmp(type, "tail") == 0) {
 133                                                 fseek(fp, - p_max_size, SEEK_END);
 134                                                 i = fread(p, 1, p_max_size - 1, fp);
 135                                                 tailstring(p, i, obj->data.headtail.wantedlines);
 136                                         } else {
 137                                                 CRIT_ERR(NULL, NULL, "If you are seeing this then there is a bug in the code, report it !");
 138                                         }
 139                                         fclose(fp);
 140                                 }
 141                         }
 142                         obj->data.headtail.buffer = strdup(p);
 143                 } else {
 144                         CRIT_ERR(NULL, NULL, "$%s can't find information about %s", type, obj->data.headtail.logfile);
 145                 }
 146         }
 147         return;
 148 }