Unlike other methods that use pipes and exec software like tr or sed or subshells, this is an extremely fast way to print a line and will always be able to detect the terminal width or else defaults to 80. It uses bash builtins for printf and echo and works with printf that supports the non-POSIX `-v` option to store result to var instead of printing to stdout.
Here it is in a function that lets you change the line character to use and the length with args, it also supports color escape sequences with the echo -e option.
function L() { local l=; builtin printf -vl "%${2:-${COLUMNS:-`tput cols 2>&-||echo 80`}}s\n" && echo -e "${l// /${1:-=}}"; }
With color:
L "`tput setaf 3`="
1. Use printf to store n space chars followed by a newline to an environment variable "l" where n is local environment variable from $COLUMNS if set, else it will use `tput cols` and if that fails it will default to 80.
2. If printf succeeds then echo `$l` that contains the chars, replacing all blank spaces with "-" (can be changed to anything you want).
From: http://www.askapache.com/linux/bash_profile-functions-advanced-shell.html http://www.askapache.com/linux/bash-power-prompt.html
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Find biggest files in a directory Show Sample Output
Prints out an ascii chart using builtin bash! Then formats using cat -t and column.
The best part is:
echo -e "${p: -3} \\0$(( $i/64*100 + $i%64/8*10 + $i%8 ))";
From: http://www.askapache.com/linux/ascii-codes-and-reference.html
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Shows files and processes of the command php
This alias is super-handy for me because it quickly shows the details of each file in the current directory. The output is nice because it is sortable, allowing you to expand this basic example to do something amazing like showing you a list of the newest files, the largest files, files with bad perms, etc..
A recursive alias would be:
alias LSR='find -mount -printf "%.5m %10M %#9u:%-9g %#5U:%-5G %TF_%TR %CF_%CR %AF_%AR %#15s [%Y] %p\n" 2>/dev/null'
From: http://www.askapache.com/linux/bash_profile-functions-advanced-shell.html
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Displays an animated hourglass for x amount of seconds Show Sample Output
Shows the IO of the raid sync
Run the alias command, then issue
ps aux | tail
and resize your terminal window (putty/console/hyperterm/xterm/etc) then issue the same command and you'll understand.
${LINES:-`tput lines 2>/dev/null||echo -n 12`}
Insructs the shell that if LINES is not set or null to use the output from `tput lines` ( ncurses based terminal access ) to get the number of lines in your terminal. But furthermore, in case that doesn't work either, it will default to using the default of 80.
The default for TAIL is to output the last 10 lines, this alias changes the default to output the last x lines instead, where x is the number of lines currently displayed on your terminal - 7. The -7 is there so that the top line displayed is the command you ran that used TAIL, ie the prompt.
Depending on whether your PS1 and/or PROMPT_COMMAND output more than 1 line (mine is 3) you will want to increase from -2. So with my prompt being the following, I need -7, or - 5 if I only want to display the commandline at the top. ( http://www.askapache.com/linux/bash-power-prompt.html )
275MB/748MB
[7995:7993 - 0:186] 06:26:49 Thu Apr 08 [askapache@n1-backbone5:/dev/pts/0 +1] ~
In most shells the LINES variable is created automatically at login and updated when the terminal is resized (28 linux, 23/20 others for SIGWINCH) to contain the number of vertical lines that can fit in your terminal window. Because the alias doesn't hard-code the current LINES but relys on the $LINES variable, this is a dynamic alias that will always work on a tty device.
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sort is way slow by default. This tells sort to use a buffer equal to half of the available free memory. It also will use multiple process for the sort equal to the number of cpus on your machine (if greater than 1). For me, it is magnitudes faster.
If you put this in your bash_profile or startup file, it will be set correctly when bash is started.
sort -S1 --parallel=2 <(echo) &>/dev/null && alias sortfast='sort -S$(($(sed '\''/MemF/!d;s/[^0-9]*//g'\'' /proc/meminfo)/2048)) $([ `nproc` -gt 1 ]&&echo -n --parallel=`nproc`)'
Alternative
echo|sort -S10M --parallel=2 &>/dev/null && alias sortfast="command sort -S$(($(sed '/MemT/!d;s/[^0-9]*//g' /proc/meminfo)/1024-200)) --parallel=$(($(command grep -c ^proc /proc/cpuinfo)*2))"
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Applies each file operator using the built-in test.
testt /home/askapache/.sq
/home/askapache/.sq
-a True - file exists.
-d True - file is a directory.
-e True - file exists.
-r True - file is readable by you.
-s True - file exists and is not empty.
-w True - the file is writable by you.
-x True - the file is executable by you.
-O True - the file is effectively owned by you.
-G True - the file is effectively owned by your group.
-N True - the file has been modified since it was last read.
Full Function:
testt ()
{
local dp;
until [ -z "${1:-}" ]; do
dp="$1";
[[ ! -a "$1" ]] && dp="$PWD/$dp";
command ls -w $((${COLUMNS:-80}-20)) -lA --color=tty -d "$dp";
[[ -d "$dp" ]] && find "$dp" -mount -depth -wholename "$dp" -printf '%.5m %10M %#15s %#9u %-9g %#5U %-5G %Am/%Ad/%AY %Cm/%Cd/%CY %Tm/%Td/%TY [%Y] %p\n' -a -quit 2> /dev/null;
for f in a b c d e f g h L k p r s S t u w x O G N;
do
test -$f "$dp" && help test | sed "/-$f F/!d" | sed -e 's#^[\t ]*-\([a-zA-Z]\{1\}\) F[A-Z]*[\t ]* True if#-\1 "'$dp'" #g';
done;
shift;
done
}
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Here is the full function (got trunctated), which is much better and works for multiple queries. function cmdfu () { local t=~/cmdfu; until [[ -z $1 ]]; do echo -e "\n# $1 {{{1" >> $t; curl -s "commandlinefu.com/commands/matching/$1/`echo -n $1|base64`/plaintext" | sed '1,2d;s/^#.*/& {{{2/g' | tee -a $t > $t.c; sed -i "s/^# $1 {/# $1 - `grep -c '^#' $t.c` {/" $t; shift; done; vim -u /dev/null -c "set ft=sh fdm=marker fdl=1 noswf" -M $t; rm $t $t.c } Searches commandlinefu for single/multiple queries and displays syntax-highlighted, folded, and numbered results in vim. Show Sample Output
This is freaking sweet!!! Here is the full alias, (I didn't want to cause display problems on commandlinefu.com's homepage):
alias tarred='( ( D=`builtin pwd`; F=$(date +$HOME/`sed "s,[/ ],#,g" <<< ${D/${HOME}/}`#-%F.tgz); S=$SECONDS; tar --ignore-failed-read --transform "s,^${D%/*},`date +${D%/*}.%F`,S" -czPf "$"F "$D" && logger -s "Tarred $D to $F in $(($SECONDS-$S)) seconds" ) & )'
Creates a .tgz archive of whatever directory it is run from, in the background, detached from current shell so if you logout it will still complete. Also, you can run this as many times as you want, if the archive .tgz already exists, it just moves it to a numbered backup '--backup=numbered'. The coolest part of this is the transformation performed by tar and sed so that the archive file names are automatically created, and when you extract the archive file it is completely safe thanks to the transform command.
If you archive lets say /home/tombdigger/new-stuff-to-backup/ it will create the archive /home/#home#tombdigger#new-stuff-to-backup#-2010-11-18.tgz Then when you extract it, like tar -xvzf #home#tombdigger#new-stuff-to-backup#-2010-11-18.tgz instead of overwriting an existing /home/tombdigger/new-stuff-to-backup/ directory, it will extract to /home/tombdigger/new-stuff-to-backup.2010-11-18/
Basically, the tar archive filename is the PWD with all '/' replaced with '#', and the date is appended to the name so that multiple archives are easily managed. This example saves all archives to your $HOME/archive-name.tgz, but I have a $BKDIR variable with my backup location for each shell user, so I just replaced HOME with BKDIR in the alias.
So when I ran this in /opt/askapache/SOURCE/lockfile-progs-0.1.11/ the archive was created at /askapache-bk/#opt#askapache#SOURCE#lockfile-progs-0.1.11#-2010-11-18.tgz
Upon completion, uses the universal logger tool to output its completion to syslog and stderr (printed to your terminal), just remove that part if you don't want it, or just remove the '-s ' option from logger to keep the logs only in syslog and not on your terminal.
Here's how my syslog server recorded this..
2010-11-18T00:44:13-05:00 gravedigger.askapache.com (127.0.0.5) [user] [notice] (logger:) Tarred /opt/askapache/SOURCE/lockfile-progs-0.1.11 to /askapache-bk/tarred/#opt#SOURCE#lockfile-progs-0.1.11#-2010-11-18.tgz in 4 seconds
Caveats
Really this is very robust and foolproof, the only issues I ever have with it (I've been using this for years on my web servers) is if you run it in a directory and then a file changes in that directory, you get a warning message and your archive might have a problem for the changed file. This happens when running this in a logs directory, a temp dir, etc.. That's the only issue I've ever had, really nothing more than a heads up.
Advanced:
This is a simple alias, and very useful as it works on basically every linux box with semi-current tar and GNU coreutils, bash, and sed.. But if you want to customize it or pass parameters (like a dir to backup instead of pwd), check out this function I use.. this is what I created the alias from BTW, replacing my aa_status function with logger, and adding $SECONDS runtime instead of using tar's --totals
function tarred ()
{
local GZIP='--fast' PWD=${1:-`pwd`} F=$(date +${BKDIR}/%m-%d-%g-%H%M-`sed -u 's/[\/\ ]/#/g'
[[ ! -r "$PWD" ]] && echo "Bad permissions for $PWD" 1>&2 && return 2;
( ( tar --totals --ignore-failed-read --transform "s@^${PWD%/*}@`date +${PWD%/*}.%m-%d-%g`@S" -czPf $F $PWD && aa_status "Completed Tarp of $PWD to $F" ) & )
}
#From my .bash_profile http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
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5 helpful aliases for using the which utility, specifically for the GNU which (2.16 tested) that is included in coreutils.
Which is run first for a command. Same as type builtin minus verbosity
alias which='{ command alias; command declare -f; } | command which --read-functions --read-alias'
Which (a)lias
alias whicha='command alias | command which --read-alias'
Which (f)unction
alias whichf='command declare -f | command which --read-functions'
Which e(x)ecutable file in PATH
alias whichx='command which'
Which (all) alias, function, builtin, and files in PATH
alias whichall='{ command alias; command declare -f; } | command which --read-functions --read-alias -a'
# From my .bash_profile http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
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Normally the bash builtin command 'set' displays all vars and functions. This just shows the vars. Useful if you want to see different output then env or declare or export.
Alias 'sete' shows sets variables
alias sete='set|sed -n "/^`declare -F|sed -n "s/^declare -f \(.*\)/\1 ()/p;q"`/q;p"'
Alias setf shows the functions.
alias setf='set|sed -n "/^`declare -F|sed -n "s/^declare -f \(.*\)/\1 ()/p;q"`/,\$p"'
Also see: http://www.commandlinefu.com/commands/view/6899/print-all-environment-variables-including-hidden-ones
At the very least, some cool sed commands!
From my .bash_profile http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
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This is very helpful to place in a shell startup file and will make grep use those options all the time. This example is nice as it won't show those warning messages, skips devices like fifos and pipes, and ignores case by default.
When debugging an ssh connection either to optimize your settings ie compression, ciphers, or more commonly for debugging an issue connecting, this alias comes in real handy as it's not easy to remember the '-o LogLevel=DEBUG3' argument, which adds a boost of debugging info not available with -vvv alone. Especially useful are the FD info, and the setup negotiation to create a cleaner, faster connection. Show Sample Output
just a leaner, smaller version. Love the original idea!
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
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Grabs the cmdline used to execute the process, and the environment that the process is being run under. This is much different than the 'env' command, which only lists the environment for the shell. This is very useful (to me at least) to debug various processes on my server. For example, this lets me see the environment that my apache, mysqld, bind, and other server processes have.
Here's a function I use:
aa_ps_all () { ( cd /proc && command ps -A -opid= | xargs -I'{}' sh -c 'test $PPID -ne {}&&test -r {}/cmdline&&echo -e "\n[{}]"&&tr -s "\000" " "<{}/cmdline&&echo&&tr -s "\000\033" "\nE"<{}/environ|sort&&cat {}/limits' ); }
From my .bash_profile at http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
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While going through the source code for the well known ps command, I read about some interesting things.. Namely, that there are a bunch of different fields that ps can try and enumerate for you. These are fields I was not able to find in the man pages, documentation, only in the source. Here is a longer function that goes through each of the formats recognized by the ps on your machine, executes it, and then prompts you whether you would like to add it or not. Adding it simply adds it to an array that is then printed when you ctrl-c or at the end of the function run. This lets you save your favorite ones and then see the command to put in your .bash_profile like mine at : http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html Note that I had to do the exec method below in order to pause with read. t () { local r l a P f=/tmp/ps c='command ps wwo pid:6,user:8,vsize:8,comm:20' IFS=' '; trap 'exec 66 exec 66 $f && command ps L | tr -s ' ' >&$f; while read -u66 l >&/dev/null; do a=${l/% */}; $c,$a k -${a//%/} -A; yn "Add $a" && P[$SECONDS]=$a; done } Show Sample Output
This is super fast and an easy way to test your terminal for 256 color support. Unlike alot of info about changing colors in the terminal, this uses the ncurses termcap/terminfo database to determine the escape codes used to generate the colors for a specific TERM. That means you can switch your terminal and then run this to check the real output.
tset xterm-256color
at any rate that is some super lean code!
Here it is in function form to stick in your .bash_profile
aa_256 ()
{
( x=`tput op` y=`printf %$((${COLUMNS}-6))s`;
for i in {0..256};
do
o=00$i;
echo -e ${o:${#o}-3:3} `tput setaf $i;tput setab $i`${y// /=}$x;
done )
}
From my bash_profile: http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
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One of the first functions programmers learn is how to print a line. This is my 100% bash builtin function to do it, which makes it as optimal as a function can be. The COLUMNS environment variable is also set by bash (including bash resetting its value when you resize your term) so its very efficient. I like pretty-output in my shells and have experimented with several ways to output a line the width of the screen using a minimal amount of code. This is like version 9,000 lol.
This function is what I use, though when using colors or other terminal features I create separate functions that call this one, since this is the lowest level type of function. It might be better named printl(), but since I use it so much it's more optimal to have the name contain less chars (both for my programming and for the internal workings).
If you do use terminal escapes this will reset to default.
tput sgr0
For implementation ideas, check my
http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
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This shows every bit of information that stat can get for any file, dir, fifo, etc. It's great because it also shows the format and explains it for each format option.
If you just want stat help, create this handy alias 'stath' to display all format options with explanations.
alias stath="stat --h|sed '/Th/,/NO/!d;/%/!d'"
To display on 2 lines:
( F=/etc/screenrc N=c IFS=$'\n'; for L in $(sed 's/%Z./%Z\n/'<<<`stat --h|sed -n '/^ *%/s/^ *%\(.\).*$/\1:%\1/p'`); do G=$(echo "stat -$N '$L' \"$F\""); eval $G; N=fc;done; )
For a similarly powerful stat-like function optimized for pretty output (and can sort by any field), check out the "lll" function
http://www.commandlinefu.com/commands/view/5815/advanced-ls-output-using-find-for-formattedsortable-file-stat-info
From my .bash_profile ->
http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
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I love this function because it tells me everything I want to know about files, more than stat, more than ls. It's very useful and infinitely expandable.
find $PWD -maxdepth 1 -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n' | sort -rgbS 50%
00761 drwxrw---x askapache:askapache 777:666 [06/10/10 | 06/10/10 | 06/10/10] [d] /web/cg/tmp
The key is:
# -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n'
which believe it or not took me hundreds of tweaking before I was happy with the output.
You can easily use this within a function to do whatever you want.. This simple function works recursively if you call it with -r as an argument, and sorts by file permissions.
lsl(){ O="-maxdepth 1";sed -n '/-r/!Q1'<<<$@ &&O=;find $PWD $O -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n'|sort -rgbS 50%; }
Personally I'm using this function because:
lll () { local a KS="1 -r -g"; sed -n '/-sort=/!Q1' <<< $@ && KS=`sed 's/.*-sort=\(.*\)/\1/g'<<<$@`;
find $PWD -maxdepth 1 -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n'|sort -k$KS -bS 50%; }
# i can sort by user
lll -sort=3
# or sort by group reversed
lll -sort=4 -r
# and sort by modification time
lll -sort=6
If anyone wants to help me make this function handle multiple dirs/files like ls, go for it and I would appreciate it.. Something very minimal would be awesome.. maybe like:
for a; do lll $a; done
Note this uses the latest version of GNU find built from source, easy to build from gnu ftp tarball. Taken from my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
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Once you get into advanced/optimized scripts, functions, or cli usage, you will use the sort command alot. The options are difficult to master/memorize however, and when you use sort commands as much as I do (some examples below), it's useful to have the help available with a simple alias. I love this alias as I never seem to remember all the options for sort, and I use sort like crazy (much better than uniq for example).
# Sorts by file permissions
find . -maxdepth 1 -printf '%.5m %10M %p\n' | sort -k1 -r -g -bS 20%
00761 drwxrw---x ./tmp
00755 drwxr-xr-x .
00701 drwx-----x ./askapache-m
00644 -rw-r--r-- ./.htaccess
# Shows uniq history fast
history 1000 | sed 's/^[0-9 ]*//' | sort -fubdS 50%
exec bash -lxv
export TERM=putty-256color
Taken from my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
Show Sample Output
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