Commands by cout (6)

  • I like the other three versions but one uses nested loops and another prints every color on a separate line. Both versions fail to reset colors before giving the prompt back. This version uses the column command to print a table so all the colors fit on one screen. It also resets colors back to normal before as a last step.

    for i in {0..255}; do echo -e "\e[38;05;${i}m${i}"; done | column -c 80 -s ' '; echo -e "\e[m"
    cout · 2010-07-21 17:30:36 1

  • -2
    find . -name '*.txt' | grep -v '\.lzma$' | xargs -n 1 lzma -f -v -3
    cout · 2010-07-21 16:58:41 1
  • This will cause bash to fix a garbled terminal before the prompt is printed. For example, if you cat a file with nonprintable character sequences, the terminal sometimes ends up in a mode where it only prints line drawing characters. This sequence will return the terminal to the standard character set after every command.

    export PS1="\[\017\033[m\033[?9l\033[?1000l\]$PS1"
    cout · 2010-07-15 19:18:05 0
  • I used to do a lot of path manipulation to set up my development environment (PATH, LD_LIBRARY_PATH, etc), and one part of my environment wasn't always aware of what the rest of the environment needed in the path. Thus resetting the entire PATH variable wasn't an option; modifying it made sense. The original version of the functions used sed, which turned out to be really slow when called many times from my bashrc, and it could take up to 10 seconds to login. Switching to parameter substitution sped things up significantly. The commands here don't clean up the path when they are done (so e.g. the path gets cluttered with colons). But the code is easy to read for a one-liner. The full function looks like this: remove_path() { eval PATHVAL=":\$$1:" PATHVAL=${PATHVAL//:$2:/:} # remove $2 from $PATHVAL PATHVAL=${PATHVAL//::/:} # remove any double colons left over PATHVAL=${PATHVAL#:} # remove colons from the beginning of $PATHVAL PATHVAL=${PATHVAL%:} # remove colons from the end of $PATHVAL export $1="$PATHVAL" } append_path() { remove_path "$1" "$2" eval PATHVAL="\$$1" export $1="${PATHVAL}:$2" } prepend_path() { remove_path "$1" "$2" eval PATHVAL="\$$1" export $1="$2:${PATHVAL}" } I tried using regexes to make this into a cleaner one-liner, but remove_path ended up being cryptic and not working as well: rp() { eval "[[ ::\$$1:: =~ ^:+($2:)?((.*):$2:)?(.*):+$ ]]"; export $1=${BASH_REMATCH[3]}:${BASH_REMATCH[4]}; }; Show Sample Output

    rp() { local p; eval p=":\$$1:"; export $1=${p//:$2:/:}; }; ap() { rp "$1" "$2"; eval export $1=\$$1$2; }; pp() { rp "$1" "$2"; eval export $1=$2:\$$1; }
    cout · 2010-07-15 18:52:01 1
  • Ssh to host1, host2, and host3, executing on each host and saving the output in {host}.log. I don't have the 'parallel' command installed, otherwise it sounds interesting and less cryptic.

    for host in host1 host2 host3; do ssh -n user@$host <command> > $host.log & done; wait
    cout · 2010-07-14 14:55:31 0
  • I like this better than some of the alternatives using -exec, because if I want to change the string, it's right there at the end of the command line. That means less editing effort and more time to drink coffee. Show Sample Output

    find . -name '*.?pp' | xargs grep -H "string"
    cout · 2010-07-14 14:41:07 0

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