Perl，sed或awk one-liner来改变文件的格式

Question

I need advice on how to change the file formatted following way file1:

A       504688
B       jobnameA
A       504690
B       jobnameB
A       504691
B       jobnameC
...

into file2:

A       B
504688  jobnameA
504690  jobnameB
504691  jobnameC
...

One solution I could think of is:

cat file1 | perl -0777 -p -e 's/\s+B/\t/' | awk '{print $2"\t"$3}'.

But I am wondering if there is more efficient way or already known practice that does this job.

Answer 1

 perl -nawe 'print "@F[1 .. $#F]", $F[0] eq "A" ? "\t" : "\n"' < /tmp/ab

Look up the options in perlrun .

Another useful one to add is -l (append newline to print), but not in this case.

Answer 2

Assuming your input file is tab separated:

echo $'A\tB'
cut -f2 filename | paste - -

Should be pretty quick because this is exactly what cut and paste were written to do.

Answer 3

awk '/^A/{num=$2}/^B/{print num,$2}' file

或者，或者，

awk '{num=$2;getline;print num,$2}' file

Answer 4

Here is an sed solution:

sed -e 'N' -e 's/A\s*\(.*\)\nB\s*\(.*\)/\1\t\2/' file

This version will also print the header at the top:

sed '1{h;s/.*/A\tB/p;g};N;s/A\s*\(.*\)\nB\s*\(.*\)/\1\t\2/' file

Or an alternative:

sed -n '/^A\s*/{s///;h};/^B\s*/{s///;H;g;s/\n/\t/p}' file

If your sed does not support semicolons as a command separator for the alternative:

sed -n '
/^A\s*/{       # if the line starts with "A"
s///             # remove the "A" and the whitespace
h                # copy the remainder into the hold space
}              # end if
/^B\s*/{       # if the line starts with "B"
s///             # remove the "B" and the whitespace 
H                # append pattern space to hold space
g                # copy hold space to pattern space
s/\n/\t/p        # replace newline with tab and print
}' file

This version will also print the header at the top:

sed -n '/^A\s*/{s///;h;1s/.*/A\tB/p};/^B\s*/{s///;H;g;s/\n/\t/p}' file

Answer 5

This will work with any header text, not just fixed A and B >>

awk '{a=$1;b=$2;getline;if(c!=1){print a,$1;c=1};print b,$2}' file1 >file2

...and it will print also header row

If you need \\t separator, then use:

awk '{a=$1;b=$2;getline;if(c!=1){print a"\t"$1;c=1};print b"\t"$2}' file1 >file2

Answer 6

这可能对你有用：

 sed -e '1i\A\tB' -e 'N;s/A\s*\(\S*\).*\nB\s*\(\S*\).*/\1\t\2/' file