CODEWITHSUNDEEP
bashunixcommand-lineprintfps
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Reputation: 13

Bash: Use printf for comma seperated columns

I'm attempting to write output from ps into two comma-separated columns with custom headers which I can write to a csv file. The target format looks like:

Process ID,Command name
282,sort
280,ps
284,head
136,bash
283,awk
281,awk

Here's the command I've composed so far:

ps -o pid="Process ID" -o comm="Command name" | (read -r; printf "%s\n" "$REPLY"; sort -k2 -r)

which produces the following output:

Process ID Command name
     23104 sort
     24756 ps
     24757 bash
     19320 bash
     23103 awk

I need to replace the whitespace characters in each line (except the first, which needs special processing) with commas. Is there a way to do said replacement in the printf command? Or am I approaching this wrong?

Upvotes: 1

Views: 1391

Answers (1)

PesaThe
PesaThe

Reputation: 7499

ps -o pid,comm --no-headers | awk 'BEGIN{print "Process ID,Command name"}{$1=$1}1' OFS=,

You can use the printf read combo. However, in your code, the printf prints only the first line read by read. The rest is printed by sort. while loop is your friend here:

printf 'Process ID,Command name\n'
while read -r id cmd; do
    printf '%s,%s\n' "$id" "$cmd"
done < <(ps -o pid,comm --no-headers)

And to have the output of ps sorted, pipe it to sort like you did, or use the --sort option:

ps -o pid,comm --no-headers --sort -comm

Upvotes: 1

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