How to print contents of column fields that have strings composed of "n" character/s using bash? - linux

Question

Say I have a file which contains:
22 30 31 3a 31 32 3a 32 " 0 9 : 1 2 : 2
30 32 30 20 32 32 3a 31 1 2 7 2 2 : 1
And, I want to print only the column fields that have string composed of 1 character. I want the output to be like this:
" 0 9 : 1 2 : 2
1 2 7 2 2 : 1
Then, I want to print only those strings that are composed of two characters, the output should be:
22 30 31 3a 31 32 3a 32
30 32 30 20 32 32 3a 31
I am a beginner and I really don't know how to do this. Thanks for your help!

Answer 1

Could you please try following, I am trying it in a different way for provided samples. Written and tested with provided samples only.
For getting values before BULK SPACE try:
awk '
{
line=$0
while(match($0,/[[:space:]]+/)){
arr=arr>RLENGTH?arr:RLENGTH
start[arr]+=RSTART+prev_start
prev_start=RSTART
$0=substr($0,RSTART+RLENGTH)
}
var=substr(line,1,start[arr]-1)
sub(/ +$/,"",var)
print var
delete start
var=arr=""
}
' Input_file
Output will be as follows.
22 30 31 3a 31 32 3a 32
30 32 30 20 32 32 3a 31
For getting values after BULK SPACE try:
awk '
{
line=$0
while(match($0,/[[:space:]]+/)){
arr=arr>RLENGTH?arr:RLENGTH
start[arr]+=RSTART+prev_start
prev_start=RSTART
$0=substr($0,RSTART+RLENGTH)
}
var=substr(line,start[arr])
sub(/^ +/,"",var)
print var
delete start
var=arr=""
}
' Input_file
Output will be as follows:
" 0 9 : 1 2 : 2
1 2 7 2 2 : 1

Answer 2

You can try
awk '{for(i=1;i<=NF;++i)if(length($i)==1)printf("%s ", $i);print("")}'
For each field, check the length and print it if it's desired. You may pass the -F option to awk if it's not separated by blanks.
The awk script is expanded as:
for( i = 1; i <= NF; ++i )
if( length( $i ) == 1 )
printf( "%s ", $i );
print( "" );
The print outside loop is to print a newline after each input line.

Answer 3

Assuming all the columns are tab-separated (So you can have a space as a column value like the second line of your sample), easy to do with a perl one-liner:
$ perl -F"\t" -lane 'BEGIN { $, = "\t" } print grep { /^.$/ } #F' foo.txt
" 0 9 : 1 2 : 2
1 2 7 2 2 : 1
$ perl -F"\t" -lane 'BEGIN { $, = "\t" } print grep { /^..$/ } #F' foo.txt
22 30 31 3a 31 32 3a 32
30 32 30 20 32 32 3a 31