Given a command that produces a list of numbers, here's how you can
sum up/add up that list.
  echo "a=0\n$(command to produce the list|sed 's/^/a=a+/')\na"|bc

This converts the output/input stream to something like
a=0
a=a+10
a=a+20
a=a+400
a=a+1200
a
which is then piped into the bc command.  This results in a single
number being output'd, in this case,
1630

For example, to sum up how much space the /dfs/clips directories were
using up in Southbury, I had run my pretty_fts_lsfldb.tcl command,
putting the output in pretty.out,
  echo "a=0\n$(grep clips pretty.out | awk '{print $5}'|sed 's/^/a=a+/')\na"|bc

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A better, cleaner way to do this is to use awk.  For example,
   df -k|awk '{a+=$3} END {print a}'
will add up the third word, the "Free" column.  Note that you don't have
to strip out all the other words, nor even the non-numeric lines as in
the title (the word "Free").
   Filesystem    1024-blocks      Free %Used    Iused %Iused Mounted on
   /dev/hd4            65536     42356   36%     2385     8% /
   /dev/hd2          1425408    585768   59%    29906     9% /usr
   /dev/hd9var        262144    194040   26%      287     1% /var
   /dev/hd3           540672    125532   77%     1504     1% /tmp
   /dev/hd1            65536     28212   57%     1080     4% /home
...

or to add up the size of all the *DAT files,
   cd /db2data/v4prod/db2mnt/v4patts
   ls -l *DAT | awk '{a+=$5} END {print a}'

returns

1.29692e+10

which is 12,969,200,000 or almost 13GB.

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To see what's in a library, 
   dump -Tv /local/lib/zlib-1.1.3/libz.a  

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Use the -w switch when diff-ing two files to ignore white space.  diff -w ...

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The maximum file size (file size limit) in a local AIX file system is
     2 GB if it's a normal JFS file system,
and 64 GB if it's a large file enabled file system.

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As root, use bootinfo -r to see how much RAM memory a particular machine has.

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To uppercase something, use dd conv=ucase.  For example, to rename everything
in your current directory to uppercase, you can try
  for i in *; do echo mv $i $(echo $i|dd conv=ucase 2>/dev/null); done

The 2>/dev/null is to get rid of the 0+1 records in.
                                     0+1 records out. lines.

Another example is converting ASCII to EBCDIC (ascii to ebcdic) or vice-versa.
   dd if=ascii.file  of=ebcdic.file conv=ebcdic
or dd if=ebcdic.file of=ascii.file  conv=ascii

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To see what maintenance level you're at, try oslevel -r

You get back something like 4330-10, which says you're at ML10.
Or for AIX 5.2.2, it'll be something like 5200-04

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To turn on the Set Group ID bit (e.g. drwxrwsr-x),
   chmod g+s  /dir/name
or chmod 2775 /dir/name

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The hostname of a system is (or can be) different than the uname.
   uname -S foo     Sets the uname
   uname -n         Displays the uname
What uses this uname, I'm not sure.  We came across it playing around with
HAMCP on dncdb3/4.

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On 1-13-2006 (Friday the 13th), I found that /dev/ipldevice was missing on the
dncdb1 & dncdb2 machines in EDC.  Don't know why, but bosboot verification kept
failing when we tried applying service.

0503-409 installp:  bosboot verification starting...
0503-497 installp:  An error occurred during bosboot verification processing.

---- end ----

1800-035 Exit status (13) returned by command.
(Command process used stdout and stderr file
descriptors connected to SMIT via pipes.)

For AIX 5.2, ln /dev/hdisk0 /dev/ipldevice so it looks like this,
ls -l /dev/hdisk[01] /dev/ipldevice
brw-------   2 root     system       14,  2 Mar 24 2005  /dev/hdisk0
brw-------   1 root     system       14,  1 Mar 24 2005  /dev/hdisk1
brw-------   2 root     system       14,  2 Mar 24 2005  /dev/ipldevice

For AIX 5.3, mknod /dev/ipldevice c 23 1 (numbers may vary), so you get
ls -l /dev/hdisk[01] /dev/ipldevice
brw-------   1 root     system       23,  1 Oct 22 05:39 /dev/hdisk0
brw-------   1 root     system       23,  0 Oct 22 05:39 /dev/hdisk1
crw-------   2 root     system       23,  0 Oct 22 05:39 /dev/ipldevice

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