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

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