Posts Tagged CLI

Remote printing at home via DropBox

Posted by on Sunday, 26 June, 2011

So, i want to often print things, however rarely am i at home to print, and by the time i get there i forget entirely about it. This is something i did one sunday evening to get printing on pretty much every device in the house to my home printer, at home or at work, or even on the road!

First of all, i setup myself a dropbox account (which is free). This is a file sharing ‘cloud’ style service which is fairly well known and popular.
I installed dropbox on my phone, my iPod touch, Work PC, Home Laptops or other computers and pretty much everything that supported it.

I used these Step by Step instructions to set it up on my gateway (which also has the printer attached) via a command line interface http://wiki.dropbox.com/TipsAndTricks/TextBasedLinuxInstall#Step-by-stepversion.

Once i had it mounted on the gateway/printing box, i ran the following commands

cd ~/Dropbox/
mkdir printer
cd printer
mkdir new done

This gives me a directory structure to work with for printing. The idea was to have a script poll the ‘new’ directory, and anything in there got sent to the printer, then moved to the ‘done’ directory. Should it not print correctly i can grab it from the done dir and retry later on.
I wrote a script named ‘script.sh’ and looked like this

#!/bin/bash
for file in `ls /home/velofille/Dropbox/printer/new/`
do lp -d laser /home/velofille/Dropbox/printer/new/$file  | mail -s "Print Job"  liz@mydomain.com
mv /home/velofille/Dropbox/printer/new/$file /home/velofille/Dropbox/printer/done/
done
chmod +x script.sh

I ran a few tests to make sure this worked ok, and sorted out a few printer driver errors. Once i had that working nicely, i added the pipe to my email address so i could confirm it printed (and any errors), then setup a crontab
*/5 * * * * /home/velofille/Dropbox/printer/script.sh >/dev/null 2>&1

That’s pretty much it in a nutshell, not overly complex or hard, the main thing will be making sure the Dropbox stays up and going.
To do this, i have the following shell script called checkdropbox.sh

#!/bin/sh
SERVICE='/home/velofille/.dropbox-dist/dropbox'
 
if ! ps ax | grep -v grep | grep $SERVICE > /dev/null
then
    /home/velofille/.dropbox-dist/dropbox &
    echo "$SERVICE is not running! Had to restart it" | mail -s "$SERVICE down" liz@mydomain.com
fi
chmod +x checkdropbox.sh

I then also put another crontab exactly the same as the printer one to run this

*/5 * * * * /home/velofille/bin/checkdropbox.sh >/dev/null 2>&1

Now i can print from pretty much anywhere in the world by simply dropping a file into a dropbox directory , then have an emailed report when that printed!


WordPress & WordPress MU mass upgrade script 3.0

Posted by on Wednesday, 23 June, 2010

Sorry for the slower than usual update this time. I was rather busy/sidetracked and left it for a day or two before doing it. Since it wasn’t a exploit fix release i figured it wasn’t a major.

Anyway, here goes the new wordpress mass upgrade script. I no longer have a wordpress MU available to test on, it should technically work, but let me know if there are any problems at all with it.

This script will search /var/www (changeable in a variable) for any wordpress install and make sure its upgraded to the latest version. It pays to check each site after the upgrade to make sure plugins all worked (and upgrade plugins before the upgrade works also!). This version has a database change so i have forced the $sitename/upgrade.php call with a wget to save you some time. This occasionally fails, for no reason i can find, so it pays to check this.

Let me know if you have any bugs at all, or any problems.

Here’s your script to upgrade them all.

wget http://b.ri.mu/files/wordpress-upgrade-3.0.sh 
sh wordpress-upgrade-3.0.sh

Next time I may endeavour to see if i can script putting sites into maintaince mode, disable plugins, upgrade etc 🙂


Linux Command Line Cheat Sheet – A list of handy commands

Posted by on Tuesday, 16 June, 2009

This is a linux command line reference for common operations.
Examples marked with • are valid/safe to paste without modification into a terminal, so
you may want to keep a terminal window open while reading this so you can cut & paste.
All these commands have been tested both on Fedora and Ubuntu.

Command Description
apropos whatis Show commands pertinent to string. See also threadsafe
man -t man | ps2pdf – > man.pdf make a pdf of a manual page
which command Show full path name of command
time command See how long a command takes
time cat Start stopwatch. Ctrl-d to stop. See also sw
nice info Run a low priority command (The “info” reader in this case)
renice 19 -p $$ Make shell (script) low priority. Use for non interactive tasks
dir navigation
cd – Go to previous directory
cd Go to $HOME directory
(cd dir && command) Go to dir, execute command and return to current dir
pushd . Put current dir on stack so you can popd back to it
alias l=’ls -l –color=auto’ quick dir listing
ls -lrt List files by date. See also newest and find_mm_yyyy
ls /usr/bin | pr -T9 -W$COLUMNS Print in 9 columns to width of terminal
find -name ‘*.[ch]’ | xargs grep -E ‘expr’ Search ‘expr’ in this dir and below. See also findrepo
find -type f -print0 | xargs -r0 grep -F ‘example’ Search all regular files for ‘example’ in this dir and below
find -maxdepth 1 -type f | xargs grep -F ‘example’ Search all regular files for ‘example’ in this dir
find -maxdepth 1 -type d | while read dir; do echo $dir; echo cmd2; done Process each item with multiple commands (in while loop)
find -type f ! -perm -444 Find files not readable by all (useful for web site)
find -type d ! -perm -111 Find dirs not accessible by all (useful for web site)
locate -r ‘file[^/]*\.txt’ Search cached index for names. This re is like glob *file*.txt
look reference Quickly search (sorted) dictionary for prefix
grep –color reference /usr/share/dict/words Highlight occurances of regular expression in dictionary
archives and compression
gpg -c file Encrypt file
gpg file.gpg Decrypt file
tar -c dir/ | bzip2 > dir.tar.bz2 Make compressed archive of dir/
bzip2 -dc dir.tar.bz2 | tar -x Extract archive (use gzip instead of bzip2 for tar.gz files)
tar -c dir/ | gzip | gpg -c | ssh user@remote ‘dd of=dir.tar.gz.gpg’ Make encrypted archive of dir/ on remote machine
find dir/ -name ‘*.txt’ | tar -c –files-from=- | bzip2 > dir_txt.tar.bz2 Make archive of subset of dir/ and below
find dir/ -name ‘*.txt’ | xargs cp -a –target-directory=dir_txt/ –parents Make copy of subset of dir/ and below
( tar -c /dir/to/copy ) | ( cd /where/to/ && tar -x -p ) Copy (with permissions) copy/ dir to /where/to/ dir
( cd /dir/to/copy && tar -c . ) | ( cd /where/to/ && tar -x -p ) Copy (with permissions) contents of copy/ dir to /where/to/
( tar -c /dir/to/copy ) | ssh -C user@remote ‘cd /where/to/ && tar -x -p’ Copy (with permissions) copy/ dir to remote:/where/to/ dir
dd bs=1M if=/dev/sda | gzip | ssh user@remote ‘dd of=sda.gz’ Backup harddisk to remote machine
rsync (Network efficient file copier: Use the –dry-run option for testing)
rsync -P rsync://rsync.server.com/path/to/file file Only get diffs. Do multiple times for troublesome downloads
rsync –bwlimit=1000 fromfile tofile Locally copy with rate limit. It’s like nice for I/O
rsync -az -e ssh –delete ~/public_html/ remote.com:’~/public_html’ Mirror web site (using compression and encryption)
rsync -auz -e ssh remote:/dir/ . && rsync -auz -e ssh . remote:/dir/ Synchronize current directory with remote one
ssh (Secure SHell)
ssh $USER@$HOST command Run command on $HOST as $USER (default command=shell)
ssh -f -Y $USER@$HOSTNAME xeyes Run GUI command on $HOSTNAME as $USER
scp -p -r $USER@$HOST: file dir/ Copy with permissions to $USER’s home directory on $HOST
ssh -g -L 8080:localhost:80 root@$HOST Forward connections to $HOSTNAME:8080 out to $HOST:80
ssh -R 1434:imap:143 root@$HOST Forward connections from $HOST:1434 in to imap:143
wget (multi purpose download tool)
(cd dir/ && wget -nd -pHEKk http://www.pixelbeat.org/cmdline.html) Store local browsable version of a page to the current dir
wget -c http://www.example.com/large.file Continue downloading a partially downloaded file
wget -r -nd -np -l1 -A ‘*.jpg’ http://www.example.com/dir/ Download a set of files to the current directory
wget ftp://remote/file[1-9].iso/ FTP supports globbing directly
wget -q -O- http://www.pixelbeat.org/timeline.html | grep ‘a href’ | head Process output directly
echo ‘wget url’ | at 01:00 Download url at 1AM to current dir
wget –limit-rate=20k url Do a low priority download (limit to 20KB/s in this case)
wget -nv –spider –force-html -i bookmarks.html Check links in a file
wget –mirror http://www.example.com/ Efficiently update a local copy of a site (handy from cron)
networking (Note ifconfig, route, mii-tool, nslookup commands are obsolete)
ethtool eth0 Show status of ethernet interface eth0
ethtool –change eth0 autoneg off speed 100 duplex full Manually set ethernet interface speed
iwconfig eth1 Show status of wireless interface eth1
iwconfig eth1 rate 1Mb/s fixed Manually set wireless interface speed
iwlist scan List wireless networks in range
ip link show List network interfaces
ip link set dev eth0 name wan Rename interface eth0 to wan
ip link set dev eth0 up Bring interface eth0 up (or down)
ip addr show List addresses for interfaces
ip addr add 1.2.3.4/24 brd + dev eth0 Add (or del) ip and mask (255.255.255.0)
ip route show List routing table
ip route add default via 1.2.3.254 Set default gateway to 1.2.3.254
tc qdisc add dev lo root handle 1:0 netem delay 20msec Add 20ms latency to loopback device (for testing)
tc qdisc del dev lo root Remove latency added above
host pixelbeat.org Lookup DNS ip address for name or vice versa
hostname -i Lookup local ip address (equivalent to host `hostname`)
whois pixelbeat.org Lookup whois info for hostname or ip address
netstat -tupl List internet services on a system
netstat -tup List active connections to/from system
windows networking (Note samba is the package that provides all this windows specific networking support)
smbtree Find windows machines. See also findsmb
nmblookup -A 1.2.3.4 Find the windows (netbios) name associated with ip address
smbclient -L windows_box List shares on windows machine or samba server
mount -t smbfs -o fmask=666,guest //windows_box/share /mnt/share Mount a windows share
echo ‘message’ | smbclient -M windows_box Send popup to windows machine (off by default in XP sp2)
text manipulation (Note sed uses stdin and stdout. Newer versions support inplace editing with the -i option)
sed ‘s/string1/string2/g’ Replace string1 with string2
sed ‘s/\(.*\)1/\12/g’ Modify anystring1 to anystring2
sed ‘/ *#/d; /^ *$/d’ Remove comments and blank lines
sed ‘:a; /\\$/N; s/\\\n//; ta’ Concatenate lines with trailing \
sed ‘s/[ \t]*$//’ Remove trailing spaces from lines
sed ‘s/\([`”$\]\)/\\\1/g’ Escape shell metacharacters active within double quotes
seq 10 | sed “s/^/      /; s/ *\(.\{7,\}\)/\1/” Right align numbers
sed -n ‘1000p;1000q Print 1000th line
sed -n ‘10,20p;20q Print lines 10 to 20
sed -n ‘s/.*<title>\(.*\)<\/title>.*/\1/ip;T;q Extract title from HTML web page
sed -i 42d ~/.ssh/known_hosts Delete a particular line
sort -t. -k1,1n -k2,2n -k3,3n -k4,4n Sort IPV4 ip addresses
echo ‘Test’ | tr ‘[:lower:]’ ‘[:upper:]’ Case conversion
tr -dc ‘[:print:]’ < /dev/urandom Filter non printable characters
history | wc -l Count lines
set operations (Note you can export LANG=C for speed. Also these assume no duplicate lines within a file)
sort file1 file2 | uniq Union of unsorted files
sort file1 file2 | uniq -d Intersection of unsorted files
sort file1 file1 file2 | uniq -u Difference of unsorted files
sort file1 file2 | uniq -u Symmetric Difference of unsorted files
join -a1 -a2 file1 file2 Union of sorted files
join file1 file2 Intersection of sorted files
join -v2 file1 file2 Difference of sorted files
join -v1 -v2 file1 file2 Symmetric Difference of sorted files
math
echo ‘(1 + sqrt(5))/2’ | bc -l Quick math (Calculate φ). See also bc
echo ‘pad=20; min=64; (100*10^6)/((pad+min)*8)’ | bc More complex (int) e.g. This shows max FastE packet rate
echo ‘pad=20; min=64; print (100E6)/((pad+min)*8)’ | python Python handles scientific notation
echo ‘pad=20; plot [64:1518] (100*10**6)/((pad+x)*8)’ | gnuplot -persist Plot FastE packet rate vs packet size
echo ‘obase=16; ibase=10; 64206’ | bc Base conversion (decimal to hexadecimal)
echo $((0x2dec)) Base conversion (hex to dec) ((shell arithmetic expansion))
units -t ‘100m/9.69s’ ‘miles/hour’ Unit conversion (metric to imperial)
units -t ‘500GB’ ‘GiB’ Unit conversion (SI to IEC prefixes)
units -t ‘1 googol’ Definition lookup
seq 100 | (tr ‘\n’ +; echo 0) | bc Add a column of numbers. See also add and funcpy
calendar
cal -3 Display a calendar
cal 9 1752 Display a calendar for a particular month year
date -d fri What date is it this friday. See also day
[ $(date -d “tomorrow” +%d) = “01” ] || exit exit a script unless it’s the last day of the month
date –date=’25 Dec’ +%A What day does xmas fall on, this year
date –date=’@2147483647′ Convert seconds since the epoch (1970-01-01 UTC) to date
TZ=’:America/Los_Angeles’ date What time is it on West coast of US (use tzselect to find TZ)
echo “mail -s ‘get the train’ P@draigBrady.com < /dev/null” | at 17:45 Email reminder
echo “DISPLAY=$DISPLAY xmessage cooker” | at “NOW + 30 minutes” Popup reminder
locales
printf “%’d\n” 1234 Print number with thousands grouping appropriate to locale
BLOCK_SIZE=\’1 ls -l get ls to do thousands grouping appropriate to locale
echo “I live in `locale territory`” Extract info from locale database
LANG=en_IE.utf8 locale int_prefix Lookup locale info for specific country. See also ccodes
locale | cut -d= -f1 | xargs locale -kc | less List fields available in locale database
recode (Obsoletes iconv, dos2unix, unix2dos)
recode -l | less Show available conversions (aliases on each line)
recode windows-1252.. file_to_change.txt Windows “ansi” to local charset (auto does CRLF conversion)
recode utf-8/CRLF.. file_to_change.txt Windows utf8 to local charset
recode iso-8859-15..utf8 file_to_change.txt Latin9 (western europe) to utf8
recode ../b64 < file.txt > file.b64 Base64 encode
recode /qp.. < file.txt > file.qp Quoted printable decode
recode ..HTML < file.txt > file.html Text to HTML
recode -lf windows-1252 | grep euro Lookup table of characters
echo -n 0x80 | recode latin-9/x1..dump Show what a code represents in latin-9 charmap
echo -n 0x20AC | recode ucs-2/x2..latin-9/x Show latin-9 encoding
echo -n 0x20AC | recode ucs-2/x2..utf-8/x Show utf-8 encoding
CDs
gzip < /dev/cdrom > cdrom.iso.gz Save copy of data cdrom
mkisofs -V LABEL -r dir | gzip > cdrom.iso.gz Create cdrom image from contents of dir
mount -o loop cdrom.iso /mnt/dir Mount the cdrom image at /mnt/dir (read only)
cdrecord -v dev=/dev/cdrom blank=fast Clear a CDRW
gzip -dc cdrom.iso.gz | cdrecord -v dev=/dev/cdrom – Burn cdrom image (use dev=ATAPI -scanbus to confirm dev)
cdparanoia -B Rip audio tracks from CD to wav files in current dir
cdrecord -v dev=/dev/cdrom -audio *.wav Make audio CD from all wavs in current dir (see also cdrdao)
oggenc –tracknum=’track’ track.cdda.wav -o ‘track.ogg’ Make ogg file from wav file
disk space (See also FSlint)
ls -lSr Show files by size, biggest last
du -s * | sort -k1,1rn | head Show top disk users in current dir. See also dutop
df -h Show free space on mounted filesystems
df -i Show free inodes on mounted filesystems
fdisk -l Show disks partitions sizes and types (run as root)
rpm -q -a –qf ‘%10{SIZE}\t%{NAME}\n’ | sort -k1,1n List all packages by installed size (Bytes) on rpm distros
dpkg-query -W -f=’${Installed-Size;10}\t${Package}\n’ | sort -k1,1n List all packages by installed size (KBytes) on deb distros
dd bs=1 seek=2TB if=/dev/null of=ext3.test Create a large test file (taking no space). See also truncate
> file truncate data of file or create an empty file
monitoring/debugging
tail -f /var/log/messages Monitor messages in a log file
strace -c ls >/dev/null Summarise/profile system calls made by command
strace -f -e open ls >/dev/null List system calls made by command
ltrace -f -e getenv ls >/dev/null List library calls made by command
lsof -p $$ List paths that process id has open
lsof ~ List processes that have specified path open
tcpdump not port 22 Show network traffic except ssh. See also tcpdump_not_me
ps -e -o pid,args –forest List processes in a hierarchy
ps -e -o pcpu,cpu,nice,state,cputime,args –sort pcpu | sed ‘/^ 0.0 /d’ List processes by % cpu usage
ps -e -orss=,args= | sort -b -k1,1n | pr -TW$COLUMNS List processes by mem usage. See also ps_mem.py
ps -C firefox-bin -L -o pid,tid,pcpu,state List all threads for a particular process
ps -p 1,2 List info for particular process IDs
last reboot Show system reboot history
free -m Show amount of (remaining) RAM (-m displays in MB)
watch -n.1 ‘cat /proc/interrupts’ Watch changeable data continuously
system information (see also sysinfo) (‘#’ means root access is required)
uname -a Show kernel version and system architecture
head -n1 /etc/issue Show name and version of distribution
cat /proc/partitions Show all partitions registered on the system
grep MemTotal /proc/meminfo Show RAM total seen by the system
grep “model name” /proc/cpuinfo Show CPU(s) info
lspci -tv Show PCI info
lsusb -tv Show USB info
mount | column -t List mounted filesystems on the system (and align output)
grep -F capacity: /proc/acpi/battery/BAT0/info Show state of cells in laptop battery
# dmidecode -q | less Display SMBIOS/DMI information
# smartctl -A /dev/sda | grep Power_On_Hours How long has this disk (system) been powered on in total
# hdparm -i /dev/sda Show info about disk sda
# hdparm -tT /dev/sda Do a read speed test on disk sda
# badblocks -s /dev/sda Test for unreadable blocks on disk sda
interactive (see also linux keyboard shortcuts)
readline Line editor used by bash, python, bc, gnuplot, …
screen Virtual terminals with detach capability, …
mc Powerful file manager that can browse rpm, tar, ftp, ssh, …
gnuplot Interactive/scriptable graphing
links Web browser
xdg-open http://www.pixelbeat.org/ open a file or url with the registered desktop application
miscellaneous
alias hd=’od -Ax -tx1z -v’ Handy hexdump. (usage e.g.: • hd /proc/self/cmdline | less)
alias realpath=’readlink -f’ Canonicalize path. (usage e.g.: • realpath ~/../$USER)
set | grep $USER Search current environment
touch -c -t 0304050607 file Set file timestamp (YYMMDDhhmm)
python -m SimpleHTTPServer Serve current directory tree at http://$HOSTNAME:8000/