busybox/miscutils/ts.c
Denys Vlasenko 3395e2a8ef ts: replace overlapping strcpy with shorter code
function                                             old     new   delta
ts_main                                              401     398      -3

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-03-26 11:41:35 +01:00

89 lines
2.1 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Copyright (C) 2019 Denys Vlasenko <vda.linux@googlemail.com>
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config TS
//config: bool "ts (450 bytes)"
//config: default y
//applet:IF_TS(APPLET(ts, BB_DIR_USR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_TS) += ts.o
//usage:#define ts_trivial_usage
//usage: "[-is] [STRFTIME]"
//usage:#define ts_full_usage ""
#include "libbb.h"
#include "common_bufsiz.h"
# include <sys/syscall.h>
int ts_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ts_main(int argc UNUSED_PARAM, char **argv)
{
struct timespec base;
unsigned opt;
char *frac;
char *fmt_dt2str;
char *line;
opt = getopt32(argv, "^" "is" "\0" "?1" /*max one arg*/);
if (opt) {
putenv((char*)"TZ=UTC0");
tzset();
}
/*argc -= optind;*/
argv += optind;
fmt_dt2str = argv[0] ? argv[0]
: (char*)(opt ? "%b %d %H:%M:%S"+6 : "%b %d %H:%M:%S");
frac = is_suffixed_with(fmt_dt2str, "%.S");
if (!frac)
frac = is_suffixed_with(fmt_dt2str, "%.s");
if (frac) {
frac++;
frac[0] = frac[1];
frac[1] = '\0';
}
#define date_buf bb_common_bufsiz1
setup_common_bufsiz();
syscall(__NR_clock_gettime, CLOCK_REALTIME, &base);
while ((line = xmalloc_fgets(stdin)) != NULL) {
struct timespec ts;
struct tm tm_time;
/* libc has incredibly messy way of doing this,
* typically requiring -lrt. We just skip all this mess
*/
syscall(__NR_clock_gettime, CLOCK_REALTIME, &ts);
if (opt) {
/* -i and/or -s */
struct timespec ts1 = ts1;
if (opt & 1) /* -i */
ts1 = ts;
//printf("%d %d\n", ts.tv_sec, base.tv_sec);
ts.tv_sec -= base.tv_sec;
//printf("%d %d\n", ts.tv_sec, base.tv_sec);
ts.tv_nsec -= base.tv_nsec;
if ((int32_t)(ts.tv_nsec) < 0) {
ts.tv_sec--;
ts.tv_nsec += 1000*1000*1000;
}
if (opt & 1) /* -i */
base = ts1;
localtime_r(&ts.tv_sec, &tm_time);
}
strftime(date_buf, COMMON_BUFSIZE, fmt_dt2str, &tm_time);
if (!frac) {
printf("%s %s", date_buf, line);
} else {
printf("%s.%06u %s", date_buf, (unsigned)ts.tv_nsec / 1000u, line);
}
free(line);
}
return EXIT_SUCCESS;
}