Commands tagged for loop (27)

  • A bitcoin "brainwallet" is a secret passphrase you carry in your brain. The Bitcoin Brainwallet Private Key Base58 Encoder is the third of three functions needed to calculate a bitcoin PRIVATE key from your "brainwallet" passphrase. This base58 encoder uses the obase parameter of the amazing bc utility to convert from ASCII-hex to base58. Tech note: bc inserts line continuation backslashes, but the "read s" command automatically strips them out. I hope that one day base58 will, like base64, be added to the amazing openssl utility. Show Sample Output


    6
    function b58encode () { local b58_lookup_table=({1..9} {A..H} {J..N} {P..Z} {a..k} {m..z}); bc<<<"obase=58;ibase=16;${1^^}"|(read -a s; for b58_index in "${s[@]}" ; do printf %s ${b58_lookup_table[ 10#"$b58_index" ]}; done); }
    nixnax · 2014-02-18 02:29:30 0
  • Each file in the current folder is uploaded to imageshack.us If the folder contains other filetypes change: for files in * to: for files in *.jpg (to upload ONLY .jpg files) Additionally you can try (results may vary): for files in *.jpg *.png The output URL is encased with BB image tags for use in a forum. Show Sample Output


    4
    imageshack() { for files in *; do curl -H Expect: -F fileupload="@$files" -F xml=yes -# "http://www.imageshack.us/index.php" | grep image_link | sed -e 's/<image_link>/[IMG]/g' -e 's/<\/image_link>/[\/IMG]/g'; done; }
    operatinghazard · 2010-10-01 06:50:04 0
  • 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 ${!A*}. Then the eval builtin makes it work in a loop. I created a function for this and use it instead of env. (by aliasing env). This is the function that given any parameters lists the variables that start with it. So 'aae B' would list all env variables starting wit B. And 'aae {A..Z} {a..z}' would list all variables starting with any letter of the alphabet. And 'aae TERM' would list all variables starting with TERM. aae(){ local __a __i __z;for __a in "[email protected]";do __z=\${!${__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 Show Sample Output


    2
    for _a in {A..Z} {a..z};do _z=\${!${_a}*};for _i in `eval echo "${_z}"`;do echo -e "$_i: ${!_i}";done;done|cat -Tsv
    AskApache · 2010-10-27 07:16:54 0
  • Change the $domain variable to whichever domain you wish to query. Works with the majority of whois info; for some that won't, you may have to compromise: domain=google.com; for a in $(whois $domain | grep "Domain servers in listed order:" --after 3 | grep -v "Domain servers in listed order:"); do echo ">>> Nameservers for $domain from $a Note that this doesn't work as well as the first one; if they have more than 3 nameservers, it won't hit them all. As the summary states, this can be useful for making sure the whois nameservers for a domain match the nameserver records (NS records) from the nameservers themselves. Show Sample Output


    2
    domain=google.com; for ns in $(whois $domain | awk -F: '/Name Server/{print $2}'); do echo ">>> Nameservers for $domain from $a <<<"; dig @$ns $domain ns +short; echo; done;
    laebshade · 2011-05-08 04:46:34 0
  • Applies each file operator using the built-in test. testt /home/askapache/.sq /home/askapache/.sq -a True - file exists. -d True - file is a directory. -e True - file exists. -r True - file is readable by you. -s True - file exists and is not empty. -w True - the file is writable by you. -x True - the file is executable by you. -O True - the file is effectively owned by you. -G True - the file is effectively owned by your group. -N True - the file has been modified since it was last read. Full Function: testt () { local dp; until [ -z "${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 } Show Sample Output


    2
    testt(){ o=abcdefghLkprsStuwxOGN;echo [email protected];for((i=0;i<${#o};i++));do c=${o:$i:1};test -$c $1 && help test | sed "/^ *-$c/!d;1q;s/^[^T]*/-$c /;s/ if/ -/";done; }
    AskApache · 2012-02-21 16:54:53 2
  • This is flatcaps tweaked command to make it work on SLES 11.2


    1
    for i in /var/spool/cron/tabs/*; do echo ${i##*/}; sed 's/^/\t/' $i; echo; done
    harpo · 2012-07-12 08:07:20 1

  • 1
    for i in `seq 1 4096`; do tr -dc A-Za-z0-9 </dev/urandom | head -c8192 > dummy$i.rnd; done
    TuxOtaku · 2013-11-11 21:27:15 1
  • Using the 'time' command, running this with 'tr' took 28 seconds (and change) each time but using base64 only took 8 seconds (and change). If the file doesn't have to be viewable, pulling straight from urandom with head only took 6 seconds (and change)


    1
    for i in {1..4096}; do base64 /dev/urandom | head -c 8192 > dummy$i.rnd ; done
    pdxdoughnut · 2013-11-12 00:36:10 2
  • Note: %~nI expands %I to a file name only (cf. http://technet.microsoft.com/en-us/library/bb490909.aspx)


    1
    FOR %I IN (*.mp4) DO \Tools\ffmpeg\bin\ffmpeg.exe -i "%I" "%~nI.mpeg"
    tomtom99 · 2013-12-25 16:43:49 0
  • Edit YYYY and MM at the beginning of the command with the year and month you want. Note that `DD=$(printf "%02d" $d)` will pad single digit integers with a leading zero. Substitute `echo $YYYY$MM$DD` at the end of the line with the command you want to launch, for instance script.pl --yyyymmdd $YYYY$MM$DD Also available on GitHub as bash util: https://github.com/fibo/yyyymmdd Show Sample Output


    1
    YYYY=2014; MM=02; for d in $(cal -h $MM $YYYY | grep "^ *[0-9]"); do DD=$(printf "%02d" $d); echo $YYYY$MM$DD; done
    fibo · 2014-02-06 11:31:57 3
  • So, I'm using a CentOS VM in VirtualBox, and created four new disks in the SCSI controller. The VM created the folders: /dev/sda /dev/sdb /dev/sdc /dev/sdd Using a 'for loop' all disks are partitioned for LVM.


    1
    for x in {a..d}; do echo -e "n\np\n\n\n\nt\n8e\nw\n" | fdisk /dev/sd"$x"; done
    jaimerosario · 2015-05-21 12:59:48 1
  • At times I find that I need to loop through a file where each value that I need to do something with is not on a separate line, but rather separated with a ":" or a ";". In this instance, I create a loop within which I define 'IFS' to be something other than a whitespace character. In this example, I iterate through a file which only has one line, and several fields separated with ":". The counter helps me define how many times I want to repeat the loop.


    0
    while [[ COUNTER -le 10 && IFS=':' ]]; do for LINE in $(cat /tmp/list); do some_command(s) $LINE; done; COUNTER=$((COUNTER+1)); done
    slashdot · 2010-09-01 15:09:59 0
  • Ever need to get some text that is a specific number of characters long? Use this function to easily generate it! Doesn't look pretty, but sure does work for testing purposes! Show Sample Output


    0
    genRandomText() { a=( a b c d e f g h i j k l m n o p q r s t u v w x y z );f=0;for i in $(seq 1 $(($1-1))); do r=$(($RANDOM%26)); if [ "$f" -eq 1 -a $(($r%$i)) -eq 0 ]; then echo -n " ";f=0;continue; else f=1;fi;echo -n ${a[$r]};done;echo"";}
    bbbco · 2012-01-20 21:18:16 0
  • Here's my version. It's a bit lengthy but I prefer it since it's all Bash.


    0
    genRandomText() { x=({a..z}); for(( i=0; i<$1; i++ )); do printf ${x[$((RANDOM%26))]}; done; printf "\n"; }
    uxseven · 2012-01-26 08:19:33 0
  • change the time that you would like to have as print interval and just use it to say whatever you want to Show Sample Output


    0
    sayspeed() { for i in $(seq 1 `echo "$1"|wc -c`); do echo -n "`echo $1 |cut -c ${i}`"; sleep 0.1s; done; echo "";}
    kundan · 2012-02-11 05:51:42 0
  • Show the crontabs of all the users. Show Sample Output


    0
    for i in /var/spool/cron/*; do echo ${i##*/}; sed 's/^/\t/' $i; echo; done
    flatcap · 2012-07-11 13:36:34 5
  • Magic line will extract almost all possible archives from current folder in its own folders. Don't forget to change USER name in sudo command. sed is used to create names for folders from archive names w/o extension. You can test sed expression, used in this command: arg='war.lan.net' ; x=$(echo $arg|sed 's/\(.*\)\..*/\1/') ; echo $x If some archives can't be extracted, install packages: apt-get install p7zip-full p7zip-rar Hope this will save a lot of your time. Enjoy.


    0
    for ARG in * ; do sudo -u USER 7z x -o"$(echo $ARG|sed 's/\(.*\)\..*/\1/')" "$ARG" ; done
    n158 · 2012-12-31 19:47:24 0
  • You can implement a FOR loop to act on one or more files returned from the IN clause. We originally found this in order to GPG decrypt a file using wildcards (where you don't know exactly the entire file name, i.e.: Test_File_??????.txt, where ?????? = the current time in HHMMSS format). Since we won't know the time the file was generated, we need to use wildcards. And as a result of GPG not handling wildcards, this is the perfect solution. Thought I would share this revelation. :-) Show Sample Output


    0
    FOR %%c in (C:\Windows\*.*) DO (echo file %%c)
    jmcclosk · 2013-01-31 15:19:54 0

  • 0
    while true; do curl -vsL -o /dev/null example.com 2>&1 | grep 503 > /dev/null || echo "OK: server is up."; sleep 8; done
    noah · 2013-06-26 15:24:51 0

  • 0
    while curl -dsL example.com 2>&1 | grep 503;do sleep 8;done;echo server up
    emile · 2013-07-10 19:03:25 0

  • 0
    for i in `ip addr show dev eth1 | grep inet | awk '{print $2}' | cut -d/ -f1`; do echo -n $i; echo -en '\t'; host $i | awk '{print $5}'; done
    TuxOtaku · 2013-09-05 17:50:33 1
  • We will turn off and stop multiple linux services using FOR LOOP. Show Sample Output


    0
    for i in rpcbind nfslock lldpad fcoe rpcidmapd; do service $i stop; chkconfig $i off; done
    prasad · 2014-01-23 05:05:22 2
  • This is not exhaustive but after checking /etc/cron* is a good way to see if there are any other jobs any users may have set. Note: this is a repost from a comment "flatcap" made on http://www.commandlinefu.com/commands/view/3726/print-crontab-entries-for-all-the-users-that-actually-have-a-crontab#comment, for which I am grateful and I take no credit.


    0
    for USER in /var/spool/cron/*; do echo "--- crontab for $USER ---"; cat "$USER"; done
    tyzbit · 2014-12-11 19:48:46 1

  • 0
    YYYY=2014; MM=02; for DD in $(cal $MM $YYYY | grep "^ *[0-9]"); do [ ${#DD} = 1 ] && DD=0$DD; echo $YYYY$MM$DD; done
    Dentorman · 2015-11-20 09:37:14 0
  • If you don't have seq, you can use perl.


    -1
    genRandomText() { perl -e '$n=shift; print chr(int(rand(26)) + 97) for 1..$n; print "\n"' $1;}
    putnamhill · 2012-01-21 00:21:20 0
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Display the output of a command from the first line until the first instance of a regular expression.
If BREs can be used, this sed version will also get the job done.

List only executables installed by a debian package
Safe for whitespaces in names.

View ~/.ssh/known_hosts key information
Will return the SSH server key information for each host you have in your ~/.ssh/known_hosts file, including key size, key fingerprint, key IP address or domain name, and key type.

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Ask for a password, the passwd-style
You can ask repeatedly for a non-blank password using this function: function read_password() { while [ ! -n "$USER_PASSWORD" ]; do read -s -p"Password: " USER_PASSWORD if [ ! -n "$USER_PASSWORD" ]; then echo "ERROR: You must specify a valid password, please try again" fi echo done } Also you can set a time out (in seconds) to write the password read -t 10 -s -p"Password: " USER_PASSWORD_VARIABLE if [ ! $? -eq 0 ]; then echo "Time out!" fi

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

An alarm clock using xmms2 and at
I like the order of the arguments better this way.

Serial console to a Vmware VM
Create a serial console with "socket (named pipe)" of "/tmp/socket", "from:server, to:virtual machine" in vmware player, etc.. gui. Run the above command after you have booted the guest OS (which should also be configured for serial console).

bulk rename files with sed, one-liner
Far from my favorite, but works in sh and with an old sed that doesn't support '-E'

Set a Reminder for yourself via the notification system
This will be seen through your system's visual notification system, notify-osd, notification-daemon, etc. --- sleep accepts s,m,h,d and floats (date; sleep .25m; date) --- notify-send (-t is in milliseconds && -u low / normal / critical) man notify-send for more information --- notification-daemon can use b/i/u/a HTML


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