platform_system_core/toolbox/dmesg.c

59 lines
1.1 KiB
C

#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <sys/klog.h>
#include <string.h>
#define FALLBACK_KLOG_BUF_SHIFT 17 /* CONFIG_LOG_BUF_SHIFT from our kernel */
#define FALLBACK_KLOG_BUF_LEN (1 << FALLBACK_KLOG_BUF_SHIFT)
int dmesg_main(int argc, char **argv)
{
char *buffer;
char *p;
ssize_t ret;
int n, op, klog_buf_len;
klog_buf_len = klogctl(KLOG_SIZE_BUFFER, 0, 0);
if (klog_buf_len <= 0) {
klog_buf_len = FALLBACK_KLOG_BUF_LEN;
}
buffer = (char *)malloc(klog_buf_len + 1);
if (!buffer) {
perror("malloc");
return EXIT_FAILURE;
}
p = buffer;
if((argc == 2) && (!strcmp(argv[1],"-c"))) {
op = KLOG_READ_CLEAR;
} else {
op = KLOG_READ_ALL;
}
n = klogctl(op, buffer, klog_buf_len);
if (n < 0) {
perror("klogctl");
return EXIT_FAILURE;
}
buffer[n] = '\0';
while((ret = write(STDOUT_FILENO, p, n))) {
if (ret == -1) {
if (errno == EINTR)
continue;
perror("write");
return EXIT_FAILURE;
}
p += ret;
n -= ret;
}
return 0;
}