Check how far along (in %) your program is in a file

f=bigdata.xz; calc "round($(lsof -o0 -o "$f"|awk '{o=substr($7,3)}END{print o}')/$(stat -c %s "$f")*100)"
Say you're started "xzcat bigdata.xz | complicated-processing-program >summary" an hour ago, and you of course forgot to enable progress output (you could've just put "awk 'NR%1000==0{print NR>"/dev/stderr"}{print}'" in the pipeline but it's too late for that now). But you really want some idea of how far along your program is. Then you can run the above command to see how many % along xzcat is in reading the file. Note that this is for the GNU/Linux version of lsof; the one found on e.g. Darwin has slightly different output so the awk part may need some tweaks.
Sample Output
        72

2
By: unhammer
2015-09-19 18:27:12

1 Alternatives + Submit Alt

  • Imagine you've started a long-running process that involves piping data, but you forgot to add the progress-bar option to a command. e.g. xz -dc bigdata.xz | complicated-processing-program > summary . This command uses lsof to see how much data xz has read from the file. lsof -o0 -o -Fo FILENAME Display offsets (-o), in decimal (-o0), in parseable form (-Fo) This will output something like: . p12607 f3 o0t45187072 . Process id (p), File Descriptor (f), Offset (o) . We stat the file to get its size stat -c %s FILENAME . Then we plug the values into awk. Split the line at the letter t: -Ft Define a variable for the file's size: -s=$(stat...) Only work on the offset line: /^o/ . Note this command was tested using the Linux version of lsof. Because it uses lsof's batch option (-F) it may be portable. . Thanks to @unhammer for the brilliant idea. Show Sample Output


    7
    F=bigdata.xz; lsof -o0 -o -Fo $F | awk -Ft -v s=$(stat -c %s $F) '/^o/{printf("%d%%\n", 100*$2/s)}'
    flatcap · 2015-09-19 22:22:43 1

What Others Think

It's very clever, but two question arise... What's calc? Why not let awk do the maths? . Also, parsing lsof output isn't reliable. The numbers of columns varies depending on things like whether the program is threaded.
flatcap · 156 weeks and 6 days ago
Removing the calc dependency is good yeah. I did not know of the -F option to lsof; thanks flatcap :-)
unhammer · 156 weeks and 5 days ago
@unhamer: No problem :-) . I didn't know about lsof -F until recently. I was trying to improve @kennethjor's command: . Print all open regular files sorted by the number of file handles open to each. http://www.commandlinefu.com/commands/view/14439 sudo lsof | egrep 'w.+REG' | awk '{print $10}' | sort | uniq -c | sort -n . Then @sesom came up with a smarter solution: http://www.commandlinefu.com/commands/view/14440 lsof -a -d 1-99 -Fn / | grep ^n | cut -b2- | sort | uniq -c | sort -n
flatcap · 156 weeks and 5 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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