adding character at the end of each string in a file

Question

I have a txt file that contains a single column of single words as such:

windfall
winnable
winner
winners
winning

I want to use the words in the file as regex strings for a mapping jobs. When finished the words should look like this:

windfall|winnable|winner|winners|winning

I need to use python or awk to open the file, place a | at the end of each and write the new content to a new file with the new character added and the column converted to a single horizontal line.

any suggestions?

Answer 1

最简单的是tr ：

tr '\n' '|' < file.txt

Answer 2

Using Python you could do:

with open('oldfile.txt') as fin:
    with open('newfile.txt', 'w') as fout:
        fout.write('|'.join(map(str.strip, fin)))

The str.split removes newlines and whitespaces, while the join concatenates the lines with | .

Answer 3

Using sed :

$ cat file
windfall
winnable
winner
winners
winning
$ sed ':a;N;s/\n/|/;ba' file
windfall|winnable|winner|winners|winning

• Create a loop using :a
• Load the new line N in to execution space
• substitute the newline with pipe
• rinse and repeat.

Answer 4

In awk, if you don't want the trailing | :

$ awk '{ s=s (NR>1"?"|":"") $0 } END { print s }' file
windfall|winnable|winner|winners|winning

The original version with getline which was basically an (not even the) outcome of an awk jamming session was:

$ awk 'BEGIN {
           while(r=getline) {         # read until EOF
               s=s (p==r?"|":"") $0;  # pile it to s, preceed with | after the first
               p=r                    # p revious r eturn value of getline
           } print s                  # out with the pile
       }' file
windfall|winnable|winner|winners|winning

Answer 5

awk -v RS= -v OFS="|" '/ /{next}$1=$1' file

windfall|winnable|winner|winners|winning

Answer 6

Use paste :

$ cat /tmp/so.txt
windfall
winnable
winner
winners
winning

$ paste -sd'|' /tmp/so.txt
windfall|winnable|winner|winners|winning

Answer 7

assuming no blank lines in between rows, and input is smaller than 500 MB , then better to keep it simple:

echo 'windfall
      winnable
      winner
      winners
      winning' | 

 {m,g,n}awk NF=NF RS= OFS='|'

windfall|winnable|winner|winners|winning