bash case statement output help

Shell Programming and Scripting
1

greetings,

I have a script that is taking input like this:

a
b
c
d
aa
bb
aaa
bbb
ccc
ddd

and formating it to be like this:
a b c d
aa bb
aaa bbb ccc ddd

however, the only way i can get this to work and not have the last line clipped off is putting the echo in the *) of the case statement which actually gives me output like this:

a
a b
a b c
a b c d
aa
aa bb
aaa
aaa bbb
aaa bbb ccc
aaa bbb ccc ddd

is there a) any way to not have to put the echo in the *) of the case statement and still get the 3 lines i need? or b) is there anything that i can use to just print out the longest line that starts with a/aa/aaa (please keep in mind i would like to be able to set the delimiter to be :'s)

If this is too confusing, let me know and i will post some sanitized output and code.

thanks!

2

It seems to me you should put an echo statement after your while loop, not in the case statement. Otherwise please post what you have tried so far, otherwise it remains a bit of a stab in the dark.

3

Gives weird cascading output
file output.txt:

a
b
c
d
aa
bb
aaa
bbb
ccc
ddd

attempts:
weird cascading output:

cat output.txt|while read LINE; do case "$LINE" in a*) unset FOO; FOO[0]="$LINE";; *) FOO[$[${#FOO[@]}+1]]="$LINE";; esac; echo ${FOO[*]}; done

and

cat output.txt|while read LINE; do case "$LINE" in a*) unset FOO;  FOO[0]="$LINE";; *) FOO[$[${#FOO[@]}+1]]="$LINE"; echo ${FOO[*]};; esac;  done

cuts off last line:

cat output.txt|while read LINE; do case "$LINE" in a*) echo ${FOO[*]}; unset FOO;  FOO[0]="$LINE";; *) FOO[$[${#FOO[@]}+1]]="$LINE";; esac;  done

gives nothing:

cat output.txt|while read LINE; do case "$LINE" in a*) unset FOO;  FOO[0]="$LINE";; *) FOO[$[${#FOO[@]}+1]]="$LINE";; esac;  done; echo ${FOO[*]}
4

Hi, try:

while read LINE
do
  case "$LINE" in 
      a*) echo ${FOO[*]}
          unset FOO
          FOO[0]="$LINE";;
       *) FOO[$[${#FOO[@]}+1]]="$LINE";;
  esac
done < output.txt
echo ${FOO[*]}

-or-

while read LINE
do
  case "$LINE" in
      a*) printf "\n"
  esac
  printf "%s" "$LINE"
done < output.txt
printf "\n"
5

The first one worked really well. Thanks!!! one last question -- what if rather than a file, i needed to grab the input from stdin? (and i can't write it out to a file first)

thanks!

[edit]

I ended up making what you gave me into its own script, and then called that from my first script and it all worked perfectly! thanks again!!