从子文件中的母文件中搜索编号，并将子文件中的整行附加回母文件中

Question

I have a file File1.txt with data in the following form

*ELEMENT_SHELL
$#   eid     pid      n1      n2      n3      n4      n5      n6         
 46573       1   48206   48210   48217   48205       0       0           
 46574       1   48205   48217   48218   48204       0       0
............................................................
.............................................................   

I want to search for the number in the third column like 48206 and search it from the other file File2.txt which has a format like under

text
text
48205       54.995392  -1.847287e-009      149.449997       0       0
48206       55.995308  -1.879442e-009      149.449997       0       0
48207       56.995224  -1.911598e-009      149.449997       0       0
text
48208       56.995224  -1.911598e-009      149.449997       0       0
...

and put the complete line along with the number back in the first file and append it at the end. so that File1.text will look like

*ELEMENT_SHELL
$#   eid     pid      n1      n2      n3      n4      n5      n6      
46573       1   48206   48210   48217   48205       0       0       
46574       1   48205   48217   48218   48204       0       0       
....................................................
............................................................
48206       55.995308  -1.879442e-009      149.449997       0       0

Any suggestion with SED or AWK?

Answer 1

With awk:

awk 'NR == FNR { print; if(NR > 2) { seen[$3] = 1 }; next } seen[$1]' file1 file2

The code works as follows:

NR == FNR {       # while processing the first file
  print           # print the line (echoing file1 fully)
  if(NR > 2) {    # from the second line onward
    seen[$3] = 1  # remember the third fields you saw
  }
  next            # don't do anything else.
}
seen[$1]          # while processing the second file: select lines
                  # whose first field is one of the remembered fields.

You can then redirect the output of this to another file and replace file1 with that file afterwards:

awk 'NR == FNR { print; if(NR > 2) { seen[$3] = 1 }; next } seen[$1]' file1 file2 > file1.new && mv file1.new file1

Answer 2

You can get the field from file1 with awk , then find the matching lines in file2 with grep and simply concatenate the files afterwards.

while read LINE
do
    SEARCHSTR=$(echo $LINE | awk '{print $3}')  
    grep "$SEARCHSTR" file2.txt >>append.txt
done < file1.txt

cat file1.txt append.txt >file1_append.txt

To have grep search for the content of different fields, a regex has to be constructed to contain them all, ie

SEARCHSTR=$(echo $LINE | awk '{BEGIN {OFS="|";} print $3, $4, $5}')  
grep "($SEARCHSTR)" file2.txt >>append.txt

Here $SEARCHSTR would already contain the content of the fields seperated by | .

Concerning speed: if the files have their columns at fixed positions, you could use cut instead of awk like this:

SEARCHSTR=$(echo $LINE | cut --output-delimiter="|" -c 15-20,21-26,27-32|tr -d " ")