1 #include <stdlib.h> 2 #include <unistd.h> 3 #include <stdio.h> 4 #include <errno.h> 5 #include <sys/klog.h> 6 #include <string.h> 7 8 #define KLOG_BUF_SHIFT 17 /* CONFIG_LOG_BUF_SHIFT from our kernel */ 9 #define KLOG_BUF_LEN (1 << KLOG_BUF_SHIFT) 10 dmesg_main(int argc,char ** argv)11int dmesg_main(int argc, char **argv) 12 { 13 char buffer[KLOG_BUF_LEN + 1]; 14 char *p = buffer; 15 ssize_t ret; 16 int n, op; 17 18 if((argc == 2) && (!strcmp(argv[1],"-c"))) { 19 op = KLOG_READ_CLEAR; 20 } else { 21 op = KLOG_READ_ALL; 22 } 23 24 n = klogctl(op, buffer, KLOG_BUF_LEN); 25 if (n < 0) { 26 perror("klogctl"); 27 return EXIT_FAILURE; 28 } 29 buffer[n] = '\0'; 30 31 while((ret = write(STDOUT_FILENO, p, n))) { 32 if (ret == -1) { 33 if (errno == EINTR) 34 continue; 35 perror("write"); 36 return EXIT_FAILURE; 37 } 38 p += ret; 39 n -= ret; 40 } 41 42 return 0; 43 } 44