System tools – toys I have foundThis topic deals with some system tools I’ve recently encounterd. I figured everyone should know about them. If you don’t see your favourite tool here, please add your comments. In some cases, I’ve merely reproduced the first bit of the man page for the command in question.
Thanks to Lazarus\ from #FreeBSD on undernet irc for prompting this topic.
See also My list of things for a new box.
lastLast will list the sessions of specified users, ttys, and hosts, in reverse time order. Each line of output contains the user name, the tty from which the session was conducted, any hostname, the start and stop times for the session, and the duration of the session. If the session is still continuing or was cut short by a crash or shutdown, last will so indicate.
stringsThis command will print the strings of printable characters in files. Very useful. strings is mainly useful for determining the contents of non-text files.
swapinfoThis command I’ve actually seen before and I’ve discussed it previously under swap files. But I figured it should be included here. I’ve not used this command often, so I can’t tell you much more about it.
su-2.02# swapinfo Device 1K-blocks Used Avail Capacity Type /dev/wd0s1b 256000 9568 246368 4% Interleaved
systatThis command displays various systems statistics. There are various options. See man systat. Here’s what it did for me.
/0 /1 /2 /3 /4 /5 /6 /7 /8 /9 /10 Load Average /0 /10 /20 /30 /40 /50 /60 /70 /80 /90 /100 <idle> XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX root systat XXX
topThis displays and updates the information about the top cpu processes. It’s dynamic and will refresh as you watch. Here’s a short sample from entering top -S -I -q:
last pid: 28805; load averages: 0.00, 0.00, 0.00 14:17:00 40 processes: 1 running, 39 sleeping CPU states: 0.4% user, 0.0% nice, 1.5% system, 0.4% interrupt, 97.7% idle Mem: 888K Active, 64K Inact, 100K Wired, 272K Cache, 1511K Buf, 1728K Free Swap: 250M Total, 6980K Used, 243M Free, 3% Inuse PID USERNAME PRI NICE SIZE RES STATE TIME WCPU CPU COMMAND 28805 root -12 -20 624K 864K RUN 0:00 3.11% 1.72% top 4 root 28 0 0K 12K update 16:27 0.04% 0.04% update 95 root 2 -12 424K 404K select 13:37 0.04% 0.04% xntpd