/* 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 USE_DMESG(NEWTOY(dmesg, "s#n#c", TOYFLAG_BIN)) config DMESG bool "dmesg" default y help usage: dmesg [-n level] [-s bufsize] | -c Print or control the kernel ring buffer. -n Set kernel logging level (1-9). -s Size of buffer to read (in bytes), default 16384. -c Clear the ring buffer after printing. */ #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 & 2) { if (klogctl(8, NULL, TT.level)) error_exit("klogctl"); } else { int size, i, last = '\n'; char *data; // Figure out how much data we need, and fetch it. size = TT.size; if (size<2) size = 16384; data = xmalloc(size); size = klogctl(3 + (toys.optflags&1), data, size); if (size < 0) error_exit("klogctl"); // Display data, filtering out level markers. for (i=0; i<size; ) { if (last=='\n' && data[i]=='<') i += 3; else xputc(last = data[i++]); } if (last!='\n') xputc('\n'); if (CFG_TOYBOX_FREE) free(data); } }