Edit text format with shell script

问题:

I am trying to make a script for text editing. In this case I have a text file named text.csv, which reads:

first;48548a;48954a,48594B
second;58757a;5875b
third;58756a;58576b;5867d;56894d;45864a

I want to make text format to like this:

first;48548a
first;48954a
first;48594B
second;58757a
second;5875b
third;58756a
third;58576b
third;5867d
third;56894d
third;45864a

What is command should I use to make this happen?

回答1:

I'd do this in awk.

Assuming your first line should have a ; instead of a ,:

$ awk -F\; '{for(n=2; n<=NF; n++) { printf("%s;%s\n",$1,$n); }}' input.txt

Untested.

回答2:

Here is a pure bash solution that handles both , and ;.

while IFS=';,' read -a data; do 
   id="${data[0]}"
   data=("${data[@]:1}")
   for item in "${data[@]}"; do 
      printf '%s;%s\n' "$id" "$item" 
   done
done < input.txt

UPDATED - alternate printing method based on chepner's suggestion:

while IFS=';,' read -a data; do 
   id="${data[0]}"
   data=("${data[@]:1}")
   printf "$id;%s\n" "${data[@]}" 
done < input.txt

回答3:

awk -v FS=';' -v OFS=';' '{for (i = 2; i <= NF; ++i) { print $1, $i }}' Explanation: awk implicitly splits data into records(by default separeted by newline, i.e. line == record) which then are split into numbered fields by given field separator(FS for input field separator and OFS for output separator). For each record this script prints first field(which is record name), along with i-th field, and that's exactly what you need.

回答4:

while IFS=';,' read -a data; do 
   id="${data[0]}"
   data=("${data[@]:1}")
   printf "$id;%s\n" "${data[@]}" 
done < input.txt

or

awk -v FS=';' -v OFS=';' '{for (i = 2; i <= NF; ++i) { print $1, $i }}'

And

$ awk -F\; '{for(n=2; n<=NF; n++) { printf("%s;%s\n",$1,$n); }}' input.txt

thanks all for your suggestions, :d. It's really give me a new knowledge..