I want to arrange following list into specific format




"42.53e-12, 43.64e-12, 45.78e-12, 49.86e-12, 57.87e-12, 73.68e-12, 105.3e-12"

All the numbers separated by commas and the list enclosed in quotes.

  • 1
    The output shows comma and space separators , , not just commas. – agc Feb 11 '18 at 18:52

Using awk:

awk '{printf (NR>1)?", "$0:"\""$0} END {print "\""}' infile

Or in another way:

awk '$1="\""$1' RS= ORS="\"\n" OFS=', ' infile

Or with combination of echo and sed commands (assuming there is no whitespaces in your file where shell word splitting is happening on that here)

sed 's/ /, /g' <(echo \"$(<infile)\")
  • awk '$1="\""$1' RS= ORS="\"\n" OFS=', ' infile gives no quotes at the end of the line. – cHiRaG Feb 11 '18 at 19:30
  1. Pure POSIX sh, (since it loads no external programs, this is fastest for small files, if dash is the current shell):

    n='"'; while read x; do n="$n$x, "; done < file; echo ${n%,*}\"
  2. Pure bash, (fastest for small files, if bash is the current shell):

    n=$(<file); echo \"${n//
    /, }\"
  3. Pure sed:

    sed -n 'H;${g;s/\n/, /g;s/, $//;s/, \(.*\)/"\1"/p}' file
  4. Shell tools:

    /bin/echo -e \"$(xargs printf "%s, " < file)'\b\b"'

A few approaches to reach the goal:

paste + sed solution:

paste -d',' -s file | sed 's/,/, /g; s/^\|$/"/g'

python solution:

python -c 'import sys; print("\""+", ".join(i.strip() for i in sys.stdin)+"\"")' <file

The output (for both approaches):

"42.53e-12, 43.64e-12, 45.78e-12, 49.86e-12, 57.87e-12, 73.68e-12, 105.3e-12"

Using Perl (on input from the file list.txt):

$ perl -e 'printf "\"%s\"\n", join ", ", map { chomp; $_ } <>' list.txt
"42.53e-12, 43.64e-12, 45.78e-12, 49.86e-12, 57.87e-12, 73.68e-12, 105.3e-12"

map is used to apply chomp; $_ on each line of input. chomp will remove the newline character and the $_ at the end will make the modified line the output of map for that input line.

join joins (concatenates) the array that map produced, inserting ,␣ (comma-space) between each element.

printf prints the concatenated string with " at start and end. The string is outputted with a newline at the very end.

Variation using print instead of printf:

perl -e 'print "\"", (join ", ", map { chomp; $_  } <>), "\"\n"' list.txt
awk 'BEGIN{ ORS=""; pre="\""}{print pre $0; pre=","}END{ORS="\n";print "\""}'

A pure sed solution:

sed '${H;g;s/\n//g;b};s/^.*$/&, /;H;d' infile
  • The OP specified surrounding double quotes, but this code doesn't output those. – agc Feb 12 '18 at 15:03

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