To calculate the size of selected list of files in a directory

>>ls -l /mnt/dd_data/rawlogs/2013052004/federation_production/acc*

31216UTC.gz

-rw-r--r--  1 yahoo dev 38158188 May 20 11:43 /mnt/dd_data/rawlogs/2013052004/federation_production/access.fed1064.yss.ac2.yahoo.com.20130520041216UTC.gz

-rw-r--r--  1 yahoo dev 40594305 May 20 11:33 /mnt/dd_data/rawlogs/2013052004/federation_production/access.fed1064.yss.sk1.yahoo.com.20130520032713UTC.gz

-rw-r--r--  1 yahoo dev 39197951 May 20 11:34 /mnt/dd_data/rawlogs/2013052004/federation_production/access.fed1064.yss.sk1.yahoo.com.20130520042713UTC.gz

-rw-r--r--  1 yahoo dev 42180531 May 20 11:50 /mnt/dd_data/rawlogs/2013052004/federation_production/access.fed1065.yss.ac2.yahoo.com.20130520033334UTC.gz

-rw-r--r--  1 yahoo dev 35726770 May 20 11:53 /mnt/dd_data/rawlogs/2013052004/federation_production/access.fed1065.yss.ac2.yahoo.com.20130520043334UTC.gz

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Now, to calculate the total size of these files, we can do as following:

>> ls -l /mnt/dd_data/rawlogs/2013052004/federation_production/acc* | awk '{SUM=SUM+$5; } END {printf "%10.0f\n", SUM}'

>>7962647332

This will give you size in bytes.

- If you want it in MBs, divide by 1024

- If you wanr it in GBs, divide by 1024*1024

To get process name OR command name using process id.

For example I want to find out the command name or process name for the process id 16874 

>> ps ax -o pid,cmd | grep 16874 | grep -v grep | cut -d " " -f2-

               1                           2                 3                 4

output : 

>> /usr/local/bin/perl -w /home/y/bin/yroot hdfs_proxy --user dkuldeep

Explanation:    

1) To get the list of PIDs and relevant commands:

>> ps ax -o pid,cmd  

>>

PID CMD

    1 init [3]

    2 [migration/0]

    3 [ksoftirqd/0]

    4 [migration/1]

    5 [ksoftirqd/1]

    6 [events/0]

    7 [events/1]

    8 [khelper]

    9 [kacpid]

   33 [kblockd/0]

   2465 /usr/sbin/snmpd -u nobody -g nobody -I -smux -Lsd -Lf /dev/null -p /var/run/snmpd.pid

   2511 /usr/sbin/automount --timeout=600 /mnt file /etc/auto.mnt

   2525 /usr/sbin/smartd

   2534 /usr/sbin/acpid

   2552 /usr/sbin/sshd-2222 -f /etc/ssh/sshd_config.2222

   16874 /usr/local/bin/perl -w /home/y/bin/yroot hdfs_proxy --user dkuldeep

2) To filter for required PID (16874)

>>ps ax -o pid,cmd | grep 16874

>>

552 grep 16874

16874 /usr/local/bin/perl -w /home/y/bin/yroot hdfs_proxy --user dkuldeep

3)  To remove the grep command line

>> ps ax -o pid,cmd | grep 16874 | grep -v grep 

>>

16874 /usr/local/bin/perl -w /home/y/bin/yroot hdfs_proxy --user dkuldeep

4) To extract the exact command line

>> ps ax -o pid,cmd | grep 16874 | grep -v grep | cut -d " " -f2-

>>
/usr/local/bin/perl -w /home/y/bin/yroot hdfs_proxy --user dkuldeep

How to sort the list of values in UNIX on command prompt

Use SORT command of Unix:

http://linux.about.com/library/cmd/blcmdl1_sort.htm

For example:

>grep 'Copied successfully' /tmp/dd_grid_data_log | awk {'print $10'} | sort -n

output:

>2

2

2

2

2

2

2

2

2

2

2

2

3

3

46

47

50

56

57

61

63

66

68

70

72

73

73

111

113

122

126

127

130