/*

* Process an LKRG logger output file. This program currently derives each

* event's ISO timestamp from several recorded relative timestamps.

*

* Written in 2022 by Solar Designer

* Copyright (c) 2022 Binarly

*/

#include <time.h>

#include <stdio.h>

static const char *format_time(char *s, size_t max, unsigned long long t)

{

time_t tu = t / 1000000;

struct tm *tm = gmtime(&tu);

if (strftime(s, max, "%Y-%m-%dT%H:%M:%SZ", tm))

return s;

return "";

}

static int process_log(const char *pathname)

{

int retval = 0;

FILE *f = fopen(pathname, "r");

if (!f) {

perror("fopen");

return 1;

}

char buf[0x2100];

while (fgets(buf, sizeof(buf), f)) {

unsigned long long tr, ts, tsu, seq, teu;

unsigned int sev;

int msgofs = 0;

int n = sscanf(buf, "%llu,%llu,%llu,%u,%llu,%llu,-;%n", &tr, &ts, &tsu, &sev, &seq, &teu, &msgofs);

if (n < 6 || !msgofs) {

if (!(retval & 2)) {

fputs("Warning: Skipping misformatted line(s)\n", stderr);

retval |= 2;

}

continue;

}

const char *msg = buf msgofs;

unsigned long long te = ts;

if (tsu > teu) {

/*

* Infer more accurate event time by subtracting the delay between send uptime

* and event uptime from the send time.

*/

te -= tsu - teu;

} else if (teu - tsu >= 500000 && !(retval & 4)) {

fputs("Warning: Major system uptime clock drift between CPUs\n", stderr);

retval |= 4;

}

char ste[21];

printf("%s %s", format_time(ste, sizeof(ste), te), msg);

}

if (ferror(f)) {

perror("fgets");

retval |= 1;

}

fclose(f);

return retval;

}

int main(int argc, const char * const *argv)

{

if (argc != 2) {

fputs("Usage: lkrg-logctl PATHNAME\n", stderr);

return 1;

}

return process_log(argv[1]);

}