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reorder member in csv file

# cat $file1 | awk -F';' '{ t = $3 ; $3 = $1; $1 = t; print; }' OFS=';' | sed 's/;/,/g' | awk -F',' '{ t = $2 ; $2 = $1; $1 = t; print; }' OFS=',' | sort > $file1.1

http://blog.fpmurphy.com/2008/10/ksh93-date-manipulation.html#sthash.oZOsKv15.dpbs

Find the line number for a specific pattern

[root@aixnim]/root# cat /etc/resolv.conf | perl -lne 'm|10.10.2.100| && print $.'
2

On AIX you can install coreutils rpm package to convert date:

epoch to date

# /opt/freeware/bin/date -d @126507600
Fri Jan  4 06:00:00  1974

Convert date to epoch

# /opt/freeware/bin/date -d "UTC 1970-01-01 126507600 secs" "+%s"
126507600

Diffrent commands exists, but sed AIX doesn't allow a option, so we can use perl:

# perl -pe 's/export TMOUT/$&\nFGOLD=\`echo "\\033[1;32m"\`/'

Print a random number between 0 and 51

# let rand=$RANDOM%52
# echo $rand

Count number of a word in a line

# echo "aa:bb:cc:dd:ee" | sed 's/[^:]//g' | awk '{ print length }'
4

# echo "a  b c     d" | tr -s " "
a b c d

Remove special characters, blank spaces, ^M, ^@, ^I etc. (control M, control I, …)

# sed 's/[^A-Za-z0-9_.;]//g'  file_name1.txt > file_name1.txt

script.sh | truss -p $$ > /tmp/truss.log 2>&1 

To log less:

truss -f -t !close -p $$ : suppress all close system call to reduce log size, and -f trace also children

trap 'command' signal_list

# kill -l : to list signals

If you have the rpm package installed : coreutils

root@aixtest /etc> /opt/freeware/bin/stat -c "%a %n" /var/adm/wtmp.1.gz
664 /var/adm/wtmp.1.gz
root@aixtest /etc> /opt/freeware/bin/stat -c "%a %n" /var
755 /var

To be able to apply permissions on files, first save the permissions in octal format, it will be easier to recover all permissions:

ls -l | awk 'BEGIN {
   v["r1"] = 400; v["w2"] = 200; v["x3"] = 100; v["s3"] = 4100; v["S3"] = 4000;
   v["r4"] = 40 ; v["w5"] = 20 ; v["x6"] = 10 ; v["s6"] = 2010; v["S6"] = 2000;
   v["r7"] = 4  ; v["w8"] = 2  ; v["x9"] = 1  ; v["t9"] = 1001; v["T9"] = 1000;
}
NF <= 2 { print $0 }
NF > 2 { val = 0; xa = " ";
   for (i = 1; i <= 9; i++) val += v[substr($1, i+1, 1)i];
   if (substr($1, 11, 1) == "+") xa = "+";
   printf " %04d%c %s\n", val, xa, $0;
}'

Or more light:

ls -l | awk 'BEGIN {
v["r1"]=400; v["w2"]=200; v["x3"]=100; v["s3"]=4100; v["S3"]=4000
v["r4"]=40 ; v["w5"]=20 ; v["x6"]=10 ; v["s6"]=2010; v["S6"]=2000
v["r7"]=4  ; v["w8"]=2  ; v["x9"]=1  ; v["t9"]=1001; v["T9"]=1000}
{val=0
 for (i=1;i<=9;i++) val=val+v[substr($0,i+1,1)i]
 printf "%4d %s\n",val,$NF}'

a='/var/spool/cron/crontabs/root'
dir=${a%/*}
file=${a##*/}

Use the “rev” reverse command so you can suppress the first occurence and the reverse again:

For example remove the version string from rpm packages: Before:

root@nimbcp - /root/scripts > rpm -qa
zip-3.0-1
unzip-6.0-2
bzip2-1.0.6-1
openldap-2.4.23-0.3
ganglia-gmond-python-examples-3.6.0-2
ganglia-mod_aixdisk-3.6.0-2

root@nimbcp - /root/scripts > rpm -qa | rev | cut -d'-' -f3- | rev
zip
unzip
bzip2
openldap
ganglia-gmond-python-examples
ganglia-mod_aixdisk

If you have a big directory with serval versions of the same rpm, you can upgrade only the packages that are installed, just exclude source packages:

root@nimbcp - /export/other/rpm # for pkgi in $(rpm -qa | sort)
do
  pkgs=$(echo $pkgi | rev | cut -d'-' -f3- | rev)
  if [ $(ls ${pkgs}-[0-9]* > /dev/null 2>&1;echo $?) -eq 0 ]
  then
    pkgn=$(ls ${pkgs}-[0-9]* | sort | grep -v ".src." | tail -1)
    if [ $(echo $pkgn | grep -v $pkgi > /dev/null 2>&1;echo $?) -eq 0 ]
    then
      echo rpm -Uhv $pkgn
    fi
  fi
done

Define an array

# myarray=(a b c)

Add an element to the array

# myarray+=(a)

List nb of elements, and list elements

# echo ${#myarray[@]}
4
# echo ${myarray[*]}
a b c a

List all elements one by one

nb=${#myarray[@]}
for ((i=0; i<nb;i++))
do
  echo ${myarray[$i]} 
done