Bash: Merging 4 lines in 4 files into one single file - bash

Question

I'm looking for a way to merge 4 lines of dna probing results into one line.
The problem here is:
I don't want to append the lines. But associating them
The 4 lines of dna probing:
A----A----------A----A-A--AAAA-
-CC----CCCC-C-----CCC-C-------C
------G----G--G--G------G------
---TT--------T-T---------T-----
I need these to be 1 line, not just appended but intermixed without the dashes.
First characters of the result:
ACCTTAGCCCCGC...
This seem to be a kind of general problem, so the language choosed to solve this don't matter.

Answer 1

For fun: one bash way:
lines=(
A----A----------A----A-A--AAAA-
-CC----CCCC-C-----CCC-C-------C
------G----G--G--G------G------
---TT--------T-T---------T-----
)
result=""
for ((i=0;i<${#lines};i++)) ;do
chr=- c=()
for ((l=0;l<${#lines[#]};l++)) ;do
[ "${lines[l]:i:1}" != "-" ] &&
chr="${lines[l]:i:1}" &&
c+=($l)
done
[ ${#c[#]} -eq 0 ] && printf 'Char #%d not replaced.\n' $i
[ ${#c[#]} -gt 1 ] && c="${c[*]}" && chr="*" &&
printf "Conflict at char #%d (lines: %s).\n" $i "${c// /, }"
result+=$chr
done
echo $result
With provided input, there is no conflict and all characters is replaced. So the output is:
ACCTTAGCCCCGCTGTAGCCCACAGTAAAAC
Note: Question stand for 4 different files, so lines= syntax could be:
lines=($(cat file1 file2 file3 file4))
But with a wrong input:
lines=(
A----A---A-----A-----A-A--AAAA-
-CC----CCCC-C-----CCC-C-------C
------G----G---G-G------G------
---TT--------T-T---------T-----
)
output could be:
Conflict at char #9 (lines: 0, 1).
Char #14 not replaced.
Conflict at char #15 (lines: 0, 2, 3).
Char #16 not replaced.
and
echo $result
ACCTTAGCC*CGCT-*-GCCCACAGTAAAAC
Small perl filter
But if input are not to be verified, this little perl filter could do the job:
(Thanks #jm666 for }{ syntax)
perl -nlE 'y+-+\0+;$,|=$_}{say$,' <(cat file1 file2 file3 file4)
where
-n process all lines without output
-l whipe leading cariage return at end of lines
y+lhs+rhs+ replace (translate) chars from 'lhs' to 'rhs'
\0 is the *null* character, binary 0.
$, is a variable
|= binary or, between himself and current line ($_)
}{ at END, once all lines processed

Answer 2

Alternative way - not very efficient - but short:
file="./gene"
line1=$(head -1 "$file")
seq ${#line1} | xargs -n1 -I% cut -c% "$file" | paste -s - | tr -cd '[A-Z\n]'
prints:
ACCTTAGCCCCGCTGTAGCCCACAGTAAAAC
Assumption: each line has the same length.
Decomposition:
the line1=$(head -1 "$file") read the 1st line into the variable line1
the seq ${#line1} generate a sequence of numbers 1..char_count_in_the_line1, like
1
2
..
31
the xargs -n1 -I% cut -c% "$file" will run for each above number the command cut like cut -c22 filename - what extract the given column from the file, e.g. you will get output like:
A
-
-
-
-
C
-
-
# and so on
the paste -s - will join the above lines into one long line with the \t (tab) separator, like:
A - - - - C - - - C - - - - - T ... etc...
finally the tr -cd '[A-Z\n]' remove everything what isn't uppercase character or newline, so will get the final
ACCTTAGCCCCGCTGTAGCCCACAGTAAAAC