Commands by empulse

Commands by empulse (3)

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Apache memory usage
This is sample output - yours may be different.
4

ps auxf | grep httpd | grep -v grep | grep -v defunct | awk '{sum=sum+$6}; END {print sum/1024}'

empulse · 2009-04-29 17:43:52 2
List SMTP connections by host

Searches /var/log/secure for smtp connections then lists these by number of connections made and hosts.
This is sample output - yours may be different.
-2

cat /var/log/secure | grep smtp | awk '{print $9}' | cut -f2 -d= | sort | uniq -c | sort -n | tail

empulse · 2009-03-30 15:49:54 2
Find brute force attempts on SSHd

Searches the /var/log/secure log file for Failed and/or invalid user log in attempts. Show Sample Output
This is sample output - yours may be different.
```
2 67.11.200.144
      4 210.40.128.31
      6 208.71.128.195
      6 64.39.0.38
     15 219.246.112.241
     20 200.214.15.142
     30 119.70.154.57
     30 79.38.22.92
     40 61.152.201.74
     87 88.191.94.168
    107 200.27.214.30
    107 61.134.27.234
    115 200.6.208.186
    170 222.73.37.25
    387 99.154.226.153
    548 222.35.78.224
    627 94.75.240.141
    946 213.191.111.5
```
8

cat /var/log/secure | grep sshd | grep Failed | sed 's/invalid//' | sed 's/user//' | awk '{print $11}' | sort | uniq -c | sort -n

empulse · 2009-03-30 15:48:24 7

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Remove any RPMs matching a pattern

This should be an option to rpm, but isn't. I wind up using it a lot because I always forget the full name of the packages I want to delete.

Show all detected mountable Drives/Partitions/BlockDevices

Yields entries in the form of "/dev/hda1" etc. Use this if you are on a new system and don't know how the storage hardware (ide, sata, scsi, usb - with ever changing descriptors) is connected and which partitions are available. Far better than using "fdisk -l" on guessed device descriptors.

Search manpages for a keyword

Search manpages for a keyword. Very useful when you don't know where to find the information.

find out which directory uses most inodes - list total sum of directoryname existing on filesystem

Print stack trace of a core file without needing to enter gdb interactively

This does almost the same thing as the original, but it runs the full backtrace for _all_ the threads, which is pretty important when reporting a crash for a multithreaded software, since more often than not, the signal handler is executed in a different thread than the crash happened.

switch case of a text file

Content search.

Grep will read the contents of each file in PWD and will use the REs $1 $2 ... $n to match the contents. In case of match, grep will print the appropriate file, line number and the matching line. It's just easier to write $ ff word1 word2 word3 Instead of $ grep -rinE 'word1|word2|word3' .

Print process run time, average CPU usage, and maximum memory usage on exit

Bash has a built-in time command which provides less functionality than the real time command. Thus we reference /usr/bin/time directly. Since the command isn't very easy to remember you could alias it to something like "cputime" or even just "time".

Download song from youtube for import into itunes (m4a format)

Last argument is the youtube link. Requires ffmpeg

run command on a group of nodes in parallel

The pee command is in the moreutils package.

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