| /* dmesg.c - display/control kernel ring buffer. |
| * |
| * Copyright 2006, 2007 Rob Landley <rob@landley.net> |
| * |
| * http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/dmesg.html |
| |
| // We care that FLAG_c is 1, so keep c at the end. |
| USE_DMESG(NEWTOY(dmesg, "trs#<1n#c[!tr]", TOYFLAG_BIN)) |
| |
| config DMESG |
| bool "dmesg" |
| default y |
| help |
| usage: dmesg [-c] [-r|-t] [-n LEVEL] [-s SIZE] |
| |
| Print or control the kernel ring buffer. |
| |
| -c Clear the ring buffer after printing |
| -n Set kernel logging LEVEL (1-9) |
| -r Raw output (with <level markers>) |
| -s Show the last SIZE many bytes |
| -t Don't print kernel's timestamps |
| */ |
| |
| #define FOR_dmesg |
| #include "toys.h" |
| #include <sys/klog.h> |
| |
| GLOBALS( |
| long level; |
| long size; |
| ) |
| |
| void dmesg_main(void) |
| { |
| // For -n just tell kernel to which messages to keep. |
| if (toys.optflags & FLAG_n) { |
| if (klogctl(8, NULL, TT.level)) perror_exit("klogctl"); |
| } else { |
| char *data, *to, *from; |
| int size; |
| |
| // Figure out how much data we need, and fetch it. |
| size = TT.size; |
| if (!size && 1>(size = klogctl(10, 0, 0))) perror_exit("klogctl");; |
| data = to = from = xmalloc(size+1); |
| size = klogctl(3 + (toys.optflags & FLAG_c), data, size); |
| if (size < 0) perror_exit("klogctl"); |
| data[size] = 0; |
| |
| // Filter out level markers and optionally time markers |
| if (!(toys.optflags & FLAG_r)) while ((from - data) < size) { |
| if (from == data || from[-1] == '\n') { |
| char *to; |
| |
| if (*from == '<' && (to = strchr(from, '>'))) from = ++to; |
| if ((toys.optflags&FLAG_t) && *from == '[' && (to = strchr(from, ']'))) |
| from = to+1+(to[1]==' '); |
| } |
| *(to++) = *(from++); |
| } else to = data+size; |
| |
| // Write result. The odds of somebody requesting a buffer of size 3 and |
| // getting "<1>" are remote, but don't segfault if they do. |
| if (to != data) { |
| xwrite(1, data, to-data); |
| if (to[-1] != '\n') xputc('\n'); |
| } |
| if (CFG_TOYBOX_FREE) free(data); |
| } |
| } |