From 30f892a0ee32ec556467e9f7bc7c46d4ed42f12e Mon Sep 17 00:00:00 2001
From: Denis Vlasenko <vda.linux@googlemail.com>
Date: Sun, 25 May 2008 01:14:14 +0000
Subject: last: code shrink
function old new delta
show_entry 319 311 -8
last_main 917 907 -10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-18) Total: -18 bytes
---
miscutils/last.c | 5 +++--
miscutils/last_fancy.c | 34 +++++++++++++++++-----------------
2 files changed, 20 insertions(+), 19 deletions(-)
diff --git a/miscutils/last.c b/miscutils/last.c
index f25411881..a84e77644 100644
--- a/miscutils/last.c
+++ b/miscutils/last.c
@@ -118,9 +118,10 @@ int last_main(int argc, char **argv ATTRIBUTE_UNUSED)
printf("%-10s %-14s %-18s %-12.12s\n",
ut.ut_user, ut.ut_line, ut.ut_host, ctime(&t_tmp) + 4);
next:
- if (!pos)
+ pos -= sizeof(ut);
+ if (pos <= 0)
break; /* done. */
- pos = lseek(file, pos - sizeof(ut), SEEK_SET);
+ xlseek(file, pos, SEEK_SET);
}
fflush_stdout_and_exit(EXIT_SUCCESS);
diff --git a/miscutils/last_fancy.c b/miscutils/last_fancy.c
index 91315d338..d234a48bf 100644
--- a/miscutils/last_fancy.c
+++ b/miscutils/last_fancy.c
@@ -57,11 +57,11 @@ static void show_entry(struct utmp *ut, int state, time_t dur_secs)
hours = mins / 60;
mins = mins % 60;
- if (days) {
+// if (days) {
sprintf(duration, "(%u+%02u:%02u)", days, hours, mins);
- } else {
- sprintf(duration, " (%02u:%02u)", hours, mins);
- }
+// } else {
+// sprintf(duration, " (%02u:%02u)", hours, mins);
+// }
logout_str = logout_time;
duration_str = duration;
@@ -100,13 +100,13 @@ static void show_entry(struct utmp *ut, int state, time_t dur_secs)
static int get_ut_type(struct utmp *ut)
{
if (ut->ut_line[0] == '~') {
- if (strncmp(ut->ut_user, "shutdown", sizeof("shutdown")-1) == 0) {
+ if (strcmp(ut->ut_user, "shutdown") == 0) {
return SHUTDOWN_TIME;
}
- if (strncmp(ut->ut_user, "reboot", sizeof("reboot")-1) == 0) {
+ if (strcmp(ut->ut_user, "reboot") == 0) {
return BOOT_TIME;
}
- if (strncmp(ut->ut_user, "runlevel", sizeof("runlevel")-1) == 0) {
+ if (strcmp(ut->ut_user, "runlevel") == 0) {
return RUN_LVL;
}
return ut->ut_type;
@@ -172,31 +172,32 @@ int last_main(int argc ATTRIBUTE_UNUSED, char **argv)
#endif
file = xopen(filename, O_RDONLY);
- if (full_read(file, &ut, sizeof(ut)) != sizeof(ut)) {
+ {
+ /* in case the file is empty... */
struct stat st;
fstat(file, &st);
start_time = st.st_ctime;
- goto exit;
}
- start_time = ut.ut_time;
time(&down_time);
going_down = 0;
boot_down = NORMAL; /* 0 */
zlist = NULL;
boot_time = 0;
- pos = 0;
+ /* get file size, rounding down to last full record */
+ pos = xlseek(file, 0, SEEK_END) / sizeof(ut) * sizeof(ut);
for (;;) {
pos -= (off_t)sizeof(ut);
- /* Bug? What if file changes size?
- * What if size is not a multiple of sizeof(ut)? */
- if (lseek(file, pos, SEEK_END) < 0) {
+ if (pos < 0) {
/* Beyond the beginning of the file boundary =>
* the whole file has been read. */
break;
}
- if (full_read(file, &ut, sizeof(ut)) != sizeof(ut))
- break;
+ xlseek(file, pos, SEEK_SET);
+ xread(file, &ut, sizeof(ut));
+ /* rewritten by each record, eventially will have
+ * first record's ut_time: */
+ start_time = ut.ut_time;
switch (get_ut_type(&ut)) {
case SHUTDOWN_TIME:
@@ -281,7 +282,6 @@ int last_main(int argc ATTRIBUTE_UNUSED, char **argv)
llist_free(zlist, free);
}
- exit:
printf("\nwtmp begins %s", ctime(&start_time));
if (ENABLE_FEATURE_CLEAN_UP)
--
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