Formatting Problem

Shell Programming and Scripting
1

Hi
Suppose we have a file consisting of nos in following format

123 - 789
123 - 828
345 - 989
345 - 792

I require the following output

123, 789,828
345, 989,792
Means Unique nos in 1st Column and Corresponding two nos in comma separated 2nd Column
Please help me out...

2 
awk -F" - " '{ if( $1 == prev ) { printf ",%s", $2 } else { printf "\n%s,%s", $1, $2; prev=$1; } }END {printf "\n"}' filename
3 
awk -F"-" ' 
{ 
   gsub(" +","",$0) ;
   arr[$1]=arr[$1] "," $2 
}
END { 
   for( key in arr ) { print key arr[key] } 
} ' file
4

## This is a traditional shell programming solution.
## It works, it can handle different cases,
## The only drawback is it has several lines of code.
##
## Run it as: cat <input_file> | <this_shell>
##
savefld1=""
Out=""
while read iLine
do
fld1=`echo $iLine | cut -f1 -d"-"`
fld2=`echo $iLine | cut -f2 -d"-"`
if [[ $fld1 = $savefld1 ]]; then
Out=$Out","$fld2
echo $Out
Out="" else
if [[ $Out != "" ]]; then

[INDENT] echo $Out
Out="" fi
Out=$fld1","$fld2 fi
savefld1=$fld1[/INDENT]done
if [[ $Out != "" ]]; then
echo $Outfi

5

This is not a traditional shell script; it is not even a POSIX shell script. It includes non-standard syntax, and doesn't take advantage of the features of the POSIX shell.

Do not run it like that! There is no need for cat:

path_to_script < INPUTFILE

In a POSIX shell, you do not need cut to split up a string:

fld1=${iLine%%-*}
fld2=${iLine#*-}

That is non-standard syntax; use the standard [ ... ] instead:

if [ "$fld1" = "$savefld1" ]; then
6

Thank you for your information, cfajohnson.

I was just trying to help Pradeepred solve his problem.

We all know that there are innumerous ways to solve a problem in unix.

For the past 26 years, I have been working for several companies where,
the four most important things are:
1- To get the job done.
2- It does not break.
3- It is easy to understand.
4- It is easy to maintain it.

Again, I was just sincerely trying to help Pradeepred.

Sorry if I broke any rule writing any code that is not considered POSIX
shell script.

Best regards,
Marcos

7

The point is that it WILL break if the original poster is not using the same shell as you.

The reason for using a POSIX shell is to make the script portable. If you use a shell-specific, non-standard syntax, you may not be helping anyone.

Every *nix system has a POSIX shell, but it may not be bash or ksh93.