Moreutils

24

Moreutils ☶ unix joeyh.name
via kb 3 years ago | cached | 10 comments

10

I love this idea - “What is in your bin directory?” was one of my first Lobsters posts. https://lobste.rs/s/f4konf/ask_lobsters_what_s_in_your_personal_bin_directory

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ssl 3 years ago | link

sponge: soak up standard input and write to a file

Ermmm, how it is different from >?
1. 4
  
  iv edited 3 years ago | link
  
  Try running the example on the page using > instead of sponge.
  
  Edit: don’t do it on /etc/passwd.
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    ssl 3 years ago | link
    
    I honestly see no difference…
    1. 7
      
      iv 3 years ago | link
      
      The behavior you see depends on the shell. On bash 3.2 for an example:
      
      $ cat foo foo bar quux $ cat foo | tr o O >foo $ cat foo $
2. 3
  
  evaryont 3 years ago | link
  
  One thing that is different is that it’s explicitly not a shell construct, independent of bash, etc. Which means you can then do command | sed | sudo sponge /etc/file. Trying to redirect the output using > would fail with a permission denied (unless your user could actually write to /etc, like root).
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    whbboyd 3 years ago | link
    
    You can hijack tee for this purpose (pipeline | sudo tee /…/file > /dev/null), but buffering stdin before writing is extremely useful. Is sponge smart enough to buffer to another file and mv it into place at the end, I wonder?
    1. 2
      
      iv 3 years ago | link
      
      Yes. See the sponge manpage.
3

jfb 3 years ago | link

I find myself often needing a realpath (1) in a shell script when all I get from the standard is a realpath (3), so I carry this around with me.

dbro 3 years ago | link

are there are good,quick,small scripts to create summary statistics and histograms for numbers? numutils is mentioned in the description of moreutils, but it doesnt appear to provide those.

atchange is a handy script to trigger a command whenever a file gets updated. I use it to automate the edit-save-run loop when writing code. It’s not technically in my /bin directory, it’s in .bash_aliases as a shell script, which I wrote after reading about the original perl script described here

# atchange $1 $2
# runs command $2 whenever file $1 is modified
function atchange(){
  if [ "$#" -lt 2 ]
  then
    echo "Insufficient arguments. Requires at least 2"
    echo "Usage: atchange [filename] [command(s)]"
  else
    FILE="$1"
    shift
    COMMAND="$@"
    oldmodtime=""
    while [ -f "$FILE" ] || ! echo "File $FILE not found" 
    do 
      #inotifywait -qq -e modify "$FILE"; # disabled to remove dependency. use polling instead
      newmodtime=`stat -c %y "$FILE"`
      if [ -z "$oldmodtime" ]; then
        oldmodtime="$newmodtime"
      fi
      if [ "$newmodtime" != "$oldmodtime" ]; then
        echo "*** atchange: $FILE change detected ($newmodtime) ***"
        sleep 1 # may not be necessary
        $COMMAND
        oldmodtime="$newmodtime"
      fi
      sleep 2 # polling interval
    done
  fi
}

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mikejsavage 3 years ago | link

Perhaps spark.