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#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>
#include <time.h>
#include <dirent.h>
#include <stdlib.h>
#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
#include "logtools.h"
void usage()
{
fprintf(stderr, "Usage: logprn logfile idle-time[:max-wait] command\n"
"\nVersion: " VERSION "\n");
exit(ERR_PARAM);
}
int main(int argc, char **argv)
{
if(argc != 4)
usage();
struct stat sBuf;
int rc = stat(argv[1], &sBuf);
if(rc)
{
printf("Can't stat \"%s\".\n", argv[1]);
return ERR_PARAM;
}
bool changed = false;
time_t mtime = sBuf.st_mtime;
ino_t inode = sBuf.st_ino;
off_t size = sBuf.st_size;
off_t print_size = size;
char *pbuf = strdup(argv[2]);
strtok(pbuf, ":");
char *maxBuf = strtok(NULL, ":");
time_t delay = atoi(pbuf);
time_t maxWait = 0;
if(maxBuf)
maxWait = atoi(maxBuf);
free(pbuf);
if(maxWait && maxWait < delay)
usage();
if(delay < 1)
usage();
time_t last_change = time(NULL);
time_t first_unwritten_change = 0;
while(1)
{
sleep(1);
rc = stat(argv[1], &sBuf);
if(rc)
{
// if failed then try again 1 second later in case of link changes etc.
sleep(1);
rc = stat(argv[1], &sBuf);
}
if(rc)
{
fprintf(stderr, "File disappeared or became unreadable.\n");
return ERR_INPUT;
}
if(inode != sBuf.st_ino)
{
inode = sBuf.st_ino;
changed = true;
mtime = sBuf.st_mtime;
print_size = 0;
size = sBuf.st_size;
last_change = time(NULL);
}
else if(mtime != sBuf.st_mtime || size != sBuf.st_size)
{
if(size > sBuf.st_size)
print_size = 0;
size = sBuf.st_size;
mtime = sBuf.st_mtime;
changed = true;
last_change = time(NULL);
if(first_unwritten_change == 0)
first_unwritten_change = last_change;
}
time_t now = time(NULL);
if(changed)
{
if((now - last_change) > delay
|| (maxWait && (now - first_unwritten_change ) > maxWait) )
{
int fd = open(argv[1], O_RDONLY);
if(fd == -1)
{
fprintf(stderr, "Can't open file \"%s\"\n", argv[1]);
return ERR_INPUT;
}
rc = lseek(fd, print_size, SEEK_SET);
if(rc == -1)
{
fprintf(stderr, "Can't lseek().\n");
}
FILE *fp = popen(argv[3], "w");
if(!fp)
{
fprintf(stderr, "Can't run \"%s\"\n", argv[3]);
return ERR_OUTPUT;
}
char buf[4096];
while( (rc = read(fd, buf, sizeof(buf))) > 0)
{
if(int(fwrite(buf, 1, rc, fp)) != rc)
{
fprintf(stderr, "Short write to pipe.\n");
break;
}
print_size += rc;
}
pclose(fp);
close(fd);
changed = false;
first_unwritten_change = 0;
}
}
}
return 0; // to make gcc happy
}
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