Commands by sonic (8)

  • From the manpage: man less -X or --no-init Disables sending the termcap initialization and deinitialization strings to the terminal. This is sometimes desirable if the deinitialization string does something unnecessary, like clearing the screen. Bonus: If you want to clear the screen after viewing a file this way that had sensitive information, hit or just type clear. Since is readily available, I don't know why less bothers to automatically clear. If you're viewing the file at all, chances are you want to see the output from it after you quit. Show Sample Output


    2
    less -X /var/log/insecure
    sonic · 2016-06-24 13:53:49 10
  • The original command is great, but I often want to prepend to every line. Show Sample Output


    1
    sed -i 's/^/ls -l /' output_files.txt
    sonic · 2013-10-07 15:12:53 2
  • Prints line numbers making it easier to see long lines that wrap in your terminal and extra line breaks at the end of a file. :set nu works too. Show Sample Output


    0
    :set number
    sonic · 2013-10-07 15:03:52 2
  • If /home/sonic/archive/ was a symlink to /backup/sonic/archive it would follow the links and give you the file listing. By default find will NOT follow symbolic links. The default behavior for the find command is to treat the symlinks as literal files. I discovered this when trying to write a script run via cron to delete files with a modification time older than X days. The easiest solution was to use: /usr/bin/find -L /home/sonic/archive -name '*gz' -type f -mtime +14 -exec rm '{}' \; Show Sample Output


    -1
    find -L /home/sonic/archive -name '*gz' -type f
    sonic · 2013-10-07 14:32:22 4
  • the advantage to doing it this way is that you can adjust the max depth to get more recursive results and run it on non GNU systems. It also won't print trailing slashes, which can easily be removed, but can be slightly annoying.. You could run: # for file in `find * -maxdepth 0 -type d`;do ls -d $file;done and in the ls -d part of the command you can put in whatever parameters you want to get things like permissions, time stamps, and ownership. Show Sample Output


    0
    find * -maxdepth 0 -type d
    sonic · 2013-02-25 21:10:49 6
  • just an alternative to setting the size, this allows you to scroll up and see your previous commands in a given session but when you logout the history is not saved. That's the only advantage to doing it this way.. Show Sample Output


    0
    export HISTFILE=/dev/null
    sonic · 2013-02-18 16:37:01 2
  • To ignore aspect ratio, run: for file in *; do convert $file -resize 800x600! resized-$file; done and all images will be exactly 800x600. Use your shell of choice.. This was done in BASH. Show Sample Output


    0
    for file in *; do convert $file -resize 800x600 resized-$file; done
    sonic · 2013-02-17 21:37:14 1
  • I couldn't find this on the site and it's a useful switch. Great for large files. Show Sample Output


    2
    wget -c or wget --continue
    sonic · 2013-02-17 21:12:00 1

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Pick a random line from a file

get you public ip address

mkdir & cd into it as single command
The biggest advantage of this over the functions is that it is portable.

Congratulations on new year
Requires installed command line PHP. Also, try at different dimensions of terminal window

list block devices
Shows all block devices in a tree with descruptions of what they are.

concatenate compressed and uncompressed logs
I use zgrep because it also parses non gzip files. With ls -tr, we parse logs in time order. Greping the empty string just concatenates all logs, but you can also grep an IP, an URL...

Insert the last argument of the previous command
for example if you did a: $ ls -la /bin/ls then $ ls !$ is equivalent to doing a $ ls /bin/ls

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Print all environment variables, including hidden ones
This uses some tricks I found while reading the bash man page to enumerate and display all the current environment variables, including those not listed by the 'env' command which according to the bash docs are more for internal use by BASH. The main trick is the way bash will list all environment variable names when performing expansion on ${!A*}. Then the eval builtin makes it work in a loop. I created a function for this and use it instead of env. (by aliasing env). This is the function that given any parameters lists the variables that start with it. So 'aae B' would list all env variables starting wit B. And 'aae {A..Z} {a..z}' would list all variables starting with any letter of the alphabet. And 'aae TERM' would list all variables starting with TERM. $ aae(){ local __a __i __z;for __a in "$@";do __z=\${!${__a}*};for __i in `eval echo "${__z}"`;do echo -e "$__i: ${!__i}";done;done; } And my printenv replacement is: $ alias env='aae {A..Z} {a..z} "_"|sort|cat -v 2>&1 | sed "s/\\^\\[/\\\\033/g"' From: http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

Avoid killing the X server with CTRL+C on the tty it was started from


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