From fd866b2f058294cf51a6987a1786ff1bd9e6b1ea Mon Sep 17 00:00:00 2001 From: Rob Landley Date: Mon, 20 Feb 2017 21:42:58 -0600 Subject: Declaring todo bankruptcy, dmesg goes back into pending until I get a chance to unify the two codepaths in Elliott's rewrite. --- toys/lsb/dmesg.c | 167 ------------------------------------------------------- 1 file changed, 167 deletions(-) delete mode 100644 toys/lsb/dmesg.c (limited to 'toys/lsb') diff --git a/toys/lsb/dmesg.c b/toys/lsb/dmesg.c deleted file mode 100644 index a991e898..00000000 --- a/toys/lsb/dmesg.c +++ /dev/null @@ -1,167 +0,0 @@ -/* dmesg.c - display/control kernel ring buffer. - * - * Copyright 2006, 2007 Rob Landley - * - * 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, "w(follow)Ctrs#<1n#c[!tr][!Cc]", TOYFLAG_BIN)) - -config DMESG - bool "dmesg" - default y - help - usage: dmesg [-Cc] [-r|-t] [-n LEVEL] [-s SIZE] [-w] - - Print or control the kernel ring buffer. - - -C Clear ring buffer without printing - -c Clear ring buffer after printing - -n Set kernel logging LEVEL (1-9) - -r Raw output (with ) - -s Show the last SIZE many bytes - -t Don't print kernel's timestamps - -w Keep waiting for more output (aka --follow) -*/ - -#define FOR_dmesg -#include "toys.h" -#include - -GLOBALS( - long level; - long size; - - int color; -) - -static int xklogctl(int type, char *buf, int len) -{ - int rc = klogctl(type, buf, len); - - if (rc<0) perror_exit("klogctl"); - - return rc; -} - -// Use klogctl for reading if we're on a pre-3.5 kernel. -static void legacy_mode() -{ - char *data, *to, *from; - int size; - - // Figure out how much data we need, and fetch it. - if (!(size = TT.size)) size = xklogctl(10, 0, 0); - data = to = from = xmalloc(size+1); - data[size = xklogctl(3 + (toys.optflags & FLAG_c), 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); -} - -static void color(int c) -{ - if (TT.color) printf("\033[%dm", c); -} - -static void print_all(void) -{ - // http://kernel.org/doc/Documentation/ABI/testing/dev-kmsg - - // Each read returns one message. By default, we block when there are no - // more messages (--follow); O_NONBLOCK is needed for for usual behavior. - int fd = xopen("/dev/kmsg", O_RDONLY | ((toys.optflags&FLAG_w)?0:O_NONBLOCK)); - - // With /dev/kmsg, SYSLOG_ACTION_CLEAR (5) doesn't actually remove anything; - // you need to seek to the last clear point. - lseek(fd, 0, SEEK_DATA); - - while (1) { - char msg[8192]; // CONSOLE_EXT_LOG_MAX. - unsigned long long time_us; - int facpri, subsystem, pos; - char *p, *text; - ssize_t len; - - // kmsg fails with EPIPE if we try to read while the buffer moves under - // us; the next read will succeed and return the next available entry. - do { - len = read(fd, msg, sizeof(msg)); - } while (len == -1 && errno == EPIPE); - // All reads from kmsg fail if you're on a pre-3.5 kernel. - if (len == -1 && errno == EINVAL) { - close(fd); - return legacy_mode(); - } - if (len <= 0) break; - - msg[len] = 0; - - if (sscanf(msg, "%u,%*u,%llu,%*[^;];%n", &facpri, &time_us, &pos) != 2) - continue; - - // Drop extras after end of message text. - text = msg + pos; - if ((p = strchr(text, '\n'))) *p = 0; - - // Is there a subsystem? (The ": " is just a convention.) - p = strstr(text, ": "); - subsystem = p ? (p - text) : 0; - - // "Raw" is a lie for /dev/kmsg. In practice, it just means we show the - // syslog facility/priority at the start of each line. - if (toys.optflags&FLAG_r) printf("<%d>", facpri); - - if (!(toys.optflags&FLAG_t)) { - color(32); - printf("[%5lld.%06lld] ", time_us/1000000, time_us%1000000); - color(0); - } - - // Errors (or worse) are shown in red, subsystems are shown in yellow. - if (subsystem) { - color(33); - printf("%.*s", subsystem, text); - text += subsystem; - color(0); - } - if (!((facpri&7) <= 3)) xputs(text); - else { - color(31); - printf("%s", text); - color(0); - xputc('\n'); - } - } - close(fd); -} - -void dmesg_main(void) -{ - TT.color = isatty(1); - - if (!(toys.optflags & (FLAG_C|FLAG_n))) print_all(); - - // Set the log level? - if (toys.optflags & FLAG_n) xklogctl(8, 0, TT.level); - - // Clear the buffer? - if (toys.optflags & (FLAG_C|FLAG_c)) xklogctl(5, 0, 0); -} -- cgit v1.2.3