Let $tail and $head work with FIFOs again (was disabled by commit 41a7cffbe7c4a4a4f04...

diff --git a/src/common.c b/src/common.c
index 697716c..4700be1 100644 (file)
--- a/src/common.c
+++ b/src/common.c
@@ -38,6 +38,7 @@
 #include <pthread.h>
 #include <unistd.h>
 #include "diskio.h"
+#include <fcntl.h>
 
 /* check for OS and include appropriate headers */
 #if defined(__linux__)
@@ -111,6 +112,27 @@ void to_real_path(char *dest, const char *source)
        }
 }
 
+int open_fifo(const char *file, int *reported)
+{
+       char path[DEFAULT_TEXT_BUFFER_SIZE];
+       int fd = 0;
+
+       to_real_path(path, file);
+       fd = open(file, O_RDONLY | O_NONBLOCK);
+
+       if (fd == -1) {
+               if (!reported || *reported == 0) {
+                       ERR("can't open %s: %s", file, strerror(errno));
+                       if (reported) {
+                               *reported = 1;
+                       }
+               }
+               return -1;
+       }
+
+       return fd;
+}
+
 FILE *open_file(const char *file, int *reported)
 {
        char path[DEFAULT_TEXT_BUFFER_SIZE];
@@ -126,7 +148,7 @@ FILE *open_file(const char *file, int *reported)
                                *reported = 1;
                        }
                }
-               return 0;
+               return NULL;
        }
 
        return fp;

diff --git a/src/common.h b/src/common.h
index d094c9d..d191406 100644 (file)
--- a/src/common.h
+++ b/src/common.h
@@ -32,7 +32,8 @@ double get_time(void);
  * DEFAULT_TEXT_BUFFER_SIZE.  It's similar to variable_substitute, except only
  * cheques for $HOME and ~/ in path */
 void to_real_path(char *dest, const char *source);
-FILE *open_file(const char *, int *);
+FILE *open_file(const char *file, int *reported);
+int open_fifo(const char *file, int *reported);
 void variable_substitute(const char *s, char *dest, unsigned int n);
 
 void format_seconds(char *buf, unsigned int n, long t);

diff --git a/src/tailhead.c b/src/tailhead.c
index 6645800..2e7b206 100644 (file)
--- a/src/tailhead.c
+++ b/src/tailhead.c
@@ -27,15 +27,37 @@
 
 #include "text_object.h"
 #include "logging.h"
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
 
 #define MAX_HEADTAIL_LINES 30
 #define DEFAULT_MAX_HEADTAIL_USES 2
 
+void tailstring(char *string, int endofstring, int wantedlines) {
+       int i, linescounted = 0;
+
+       string[endofstring] = 0;
+       if(endofstring > 0) {
+               if(string[endofstring-1] == '\n') {     //work with or without \n at end of file
+                       string[endofstring-1] = 0;
+               }
+               for(i = endofstring - 1; i >= 0 && linescounted < wantedlines; i--) {
+                       if(string[i] == '\n') {
+                               linescounted++;
+                       }
+               }
+               if(i > 0) {
+                       strfold(string, i+2);
+               }
+       }
+}
+
 void init_tailhead(const char* type, const char* arg, struct text_object *obj, void* free_at_crash) {
        unsigned int args;
 
        if(arg) {
-               obj->data.headtail.logfile=malloc(strlen(arg));
+               obj->data.headtail.logfile=malloc(DEFAULT_TEXT_BUFFER_SIZE);
                obj->data.headtail.max_uses = DEFAULT_MAX_HEADTAIL_USES;
                args = sscanf(arg, "%s %d %d", obj->data.headtail.logfile, &obj->data.headtail.wantedlines, &obj->data.headtail.max_uses);
                if(args == 2 || args == 3) {
@@ -61,45 +83,62 @@ void init_tailhead(const char* type, const char* arg, struct text_object *obj, v
 }
 
 void print_tailhead(const char* type, struct text_object *obj, char *p, int p_max_size) {
-       int i, endofstring = 0, linescounted = 0;
+       int fd, i, endofstring = 0, linescounted = 0;
        FILE *fp;
+       struct stat st;
 
+       //empty the buffer and reset the counter if we used it the max number of times
        if(obj->data.headtail.buffer && obj->data.headtail.current_use >= obj->data.headtail.max_uses - 1) {
                free(obj->data.headtail.buffer);
                obj->data.headtail.buffer = NULL;
                obj->data.headtail.current_use = 0;
        }
+       //use the buffer if possible
        if(obj->data.headtail.buffer) {
                strcpy(p, obj->data.headtail.buffer);
                obj->data.headtail.current_use++;
-       }else{
-               fp = open_file(obj->data.headtail.logfile, &obj->a);
-               if(fp != NULL) {
-                       if(strcmp(type,"head") == 0) {
-                               for(i = 0; i < obj->data.headtail.wantedlines; i++) {
-                                       fgets(p + endofstring, p_max_size - endofstring, fp);
-                                       endofstring = strlen(p);
-                               }
-                       } else if(strcmp(type,"tail") == 0) {
-                               fseek(fp, - p_max_size, SEEK_END);
-                               fread(p, 1, p_max_size, fp);
-                               p[p_max_size - 1] = 0;
-                               if(p[strlen(p)-1] == '\n') {    //work with or without \n at end of file
-                                       p[strlen(p)-1] = 0;
-                               }
-                               for(i = strlen(p); i >= 0 && linescounted < obj->data.headtail.wantedlines; i--) {
-                                       if(p[i] == '\n') {
-                                               linescounted++;
+       }else{  //otherwise find the needed data
+               if(stat(obj->data.headtail.logfile, &st) == 0) {
+                       if (S_ISFIFO(st.st_mode)) {
+                               fd = open_fifo(obj->data.headtail.logfile, &obj->a);
+                               if(fd != -1) {
+                                       if(strcmp(type, "head") == 0) {
+                                               for(i = 0; linescounted < obj->data.headtail.wantedlines; i++) {
+                                                       read(fd, p + i, 1);
+                                                       if(p[i] == '\n') {
+                                                               linescounted++;
+                                                       }
+                                               }
+                                               p[i] = 0;
+                                       } else if(strcmp(type, "tail") == 0) {
+                                               i = read(fd, p, p_max_size - 1);
+                                               tailstring(p, i, obj->data.headtail.wantedlines);
+                                       } else {
+                                               CRIT_ERR(NULL, NULL, "If you are seeing this then there is a bug in the code, report it !");
                                        }
                                }
-                               if(i > 0) {
-                                       strfold(p, i+2);
-                               }
+                               close(fd);
                        } else {
-                               CRIT_ERR(NULL, NULL, "If you are seeing this then there is a bug in the code, report it !");
+                               fp = open_file(obj->data.headtail.logfile, &obj->a);
+                               if(fp != NULL) {
+                                       if(strcmp(type, "head") == 0) {
+                                               for(i = 0; i < obj->data.headtail.wantedlines; i++) {
+                                                       fgets(p + endofstring, p_max_size - endofstring, fp);
+                                                       endofstring = strlen(p);
+                                               }
+                                       } else if(strcmp(type, "tail") == 0) {
+                                               fseek(fp, - p_max_size, SEEK_END);
+                                               i = fread(p, 1, p_max_size - 1, fp);
+                                               tailstring(p, i, obj->data.headtail.wantedlines);
+                                       } else {
+                                               CRIT_ERR(NULL, NULL, "If you are seeing this then there is a bug in the code, report it !");
+                                       }
+                                       fclose(fp);
+                               }
                        }
-                       fclose(fp);
                        obj->data.headtail.buffer = strdup(p);
+               } else {
+                       CRIT_ERR(NULL, NULL, "$%s can't find information about %s", type, obj->data.headtail.logfile);
                }
        }
        return;