Linux Tricks
The linux commadline by william shotts
Find OS version
debian
$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description: Debian GNU/Linux 7.6 (wheezy)
Release: 7.6
Codename: wheezy
mkfs
vfat with gpt?
pcworld.com/article/ How to format an SD card in Linux By Swapnil Bhartiya
lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
...
sde 8:64 1 29.2G 0 disk
└─sde1 8:65 1 29.2G 0 part /media/usb0
sudo umount /media/usb0
sudo parted /dev/sde
(parted) rm 1
(parted) mklabel msdos
(parted) mkpart primary fat32 1MiB 100%
(parted) quit
lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
...
sde 8:64 1 29.2G 0 disk
└─sde1 8:65 1 29.2G 0 part
sudo mkfs.vfat /dev/sde1
sudo umount /media/usb0
sudo parted /dev/sde
(parted) rm 1
(parted) mklabel gpt
(parted) mkpart primary fat32 1MiB 100%
(parted) quit
lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
...
sde 8:64 1 29.2G 0 disk
└─sde1 8:65 1 29.2G 0 part
sudo mkfs.vfat -n zipclip1 /dev/sde1
sudo blkid /dev/sde1
/dev/sde1: LABEL="zipclip1" UUID="BD91-9CDD" TYPE="vfat" PARTLABEL="primary" PARTUUID="ca874ec2-2ef1-44a7-bfe2-777a0234826f"
sudo umount /media/usb0
sudo parted /dev/sde
(parted) rm 1
(parted) mklabel msdos
(parted) mkpart primary fat32 1MiB 100%
(parted) quit
lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
...
sde 8:64 1 29.2G 0 disk
└─sde1 8:65 1 29.2G 0 part
sudo mkfs.vfat -n zipclip1 /dev/sde1
sudo blkid /dev/sde1
/dev/sde1: LABEL="zipclip1" UUID="BD91-9CDD" TYPE="vfat" PARTLABEL="primary" PARTUUID="ca874ec2-2ef1-44a7-bfe2-777a0234826f"
fstab entry
LABEL=zipclip1 /media/craig/zipclip auto user,auto,nofail 0 2
LABEL=zipclip1 /media/craig/zipclip auto user,auto,nofail,uid=craig 0 2
ddumont.wordpress.com/2016/04/24 Automount usb devices with systemd
Last but not least, using a plain device file (like /dev/sr0) works fine to automount optical devices. But it is difficult to predict the name of a device file created for a usb drive, so a LABEL or a UID should be used in /etc/fstab instead of a plain device file. I.e. something like:
LABEL=my_usb_drive /mnt/my-drive auto defaults,auto,nofail 0 2
mkfs for windows
FAT32 is the oldest file system here. It was introduced all the way back in Windows 95 to replace the older FAT16 file system.
NTFS is the modern file system Windows likes to use. When you install Windows, it formats your system drive with the NTFS file system. NTFS has file size and partition size limits that are so theoretically huge you won’t run up against them. NTFS first appeared in consumer versions of Windows with Windows XP.
exFAT was introduced in 2006, and was added to older versions of Windows with updates to Windows XP and Windows Vista. It’s a file system optimized for flash drives. It’s designed to be a lightweight file system like FAT32 without all NTFS’s extra features and overhead, but without FAT32’s limitations. Like NTFS, exFAT has very large file size and partition size limits. This means you can store files that are larger than 4 GB apiece on a flash drive or SD card if it’s formatted with exFAT. exFAT is a strict upgrade over FAT32, and should be the best choice for external drives where you want a lightweight file system without FAT32’s file size limits. exFAT is also more compatible than NTFS. While Mac OS X includes only read-only support for NTFS, Macs offer full read-write support for exFAT. exFAT drives can be accessed on Linux by installing the appropriate software.
mkfs.ntfs
sudo apt-get install exfat-utils exfat-fuse
mkexfatfs - create an exFAT file system
-n volume-name
mkntfs
--label label-name
-U, --with-uuid
Generate a random volume UUID.
groups
$ groups craig
craig : craig dialout cdrom floppy sudo audio dip video plugdev netdev lpadmin scanner vboxusers gammu
Add a User to a Group (or Second Group) on Linux
Changing the group a user is associated to is a fairly easy task, but not everybody knows the commands, especially to add a user to a secondary group. We’ll walk through all the scenarios for you.
Add a New Group
To add a new group, all you need to do is use the groupadd command like so:
groupadd <groupname>
Add an Existing User to a Group
Next we’ll add a user to the group, using this syntax:
usermod -a -G <groupname> username
For example, to add user geek to the group admins, use the following command:
usermod -a -G admins geek
Change a User’s Primary Group
Sometimes you might want to switch out the primary group that a user is assigned to, which you can do with this command:
usermod -g <groupname> username
View a User’s Group Assignments
If you’re trying to figure out a permissions issue, you’ll want to use the id command to see what groups the user is assigned to:
id <username>
This will display output something like this:
uid=500(howtogeek) gid=500(howtogeek) groups=500(howtogeek), 1093(admins)
You can also use the groups command if you prefer, though it is the same
as using id -Gn
groups <username>
View a List of All Groups
To view all the groups on the system, you can just use the groups command:
groups
Add a New User and Assign a Group in One Command
Sometimes you might need to add a new user that has access to a particular resource or directory, like adding a new FTP user. You can do so with the useradd command:
useradd -g <groupname> username
For instance, lets say you wanted to add a new user named jsmith to the ftp group:
useradd -G ftp jsmith
And then you’ll want to assign a password for that user, of course:
passwd jsmith
Add a User to Multiple Groups
You can easily add a user to more than one group by simply specifying them in a comma-delimited list, as long as you are assigning the secondary groups:
usermod -a -G ftp,admins,othergroup <username>
That should cover everything you need to know about adding users to groups on Linux.
Debian System Groups
Scraping Web Sites
wget can get a local copy of a url.
wget --convert-links --adjust-extension --page-requisites --no-parent http://www.guitaralive.org/playlist_14_31.html
wget --convert-links --adjust-extension --page-requisites --no-parent http://www.cpr.org/classical/playlist
HTML Tidy can be used as part of editing the scraped HTML
Archive and Compression
7zip tar archives
7zip
apt-get install p7zip-full
7z a archive.tar.7z archive.tar
Research and sites and links
sed
grymoire.com/Unix Sed Tutorial by Bruce Barnett
sed script to strip ebook scripture copy text
awk
Bruce Barnett - Grymoire Awk Tutorial
Grymoire Grymoire Awk Tutorial
This page includes Bruce Barnett’s tutorials on UNIX shell programming and various other arcane subjects of interest to wizards.
Since AWK is also an interpretor, like the shell, you can save yourself a step and make the file executable by add one line in the beginning of the file:
I prefer this format when possible. It’s shorter and simpler. It’s also easier to debug problems.
Stand alone awk script
#!/usr/bin/awk -f
BEGIN {
print "BEGIN here";
exit;
}
Daniel Robbins - Awk Tutorial at IBM Developer Works
Tutorial at IBM Developer Works Common threads: Awk by example, Part 1
Awk is a very nice language with a very strange name. In this first article of a three-part series, Daniel Robbins will quickly get your awk programming skills up to speed.
techblog.netflix
Linux Performance Analysis in 1 min.
Linux Performance Analysis in 1 min.
uptime
dmesg | tail
vmstat 1
mpstat -P ALL 1
pidstat 1
iostat -xz 1
free -m
sar -n DEV 1
sar -n TCP,ETCP 1
top
SD Cards
Debian groups
plugdev: Allows members to mount (only with the options nodev and nosuid, for security reasons) and umount removable devices through pmount.
cdrom: This group can be used locally to give a set of users access to a CDROM drive and other optical drives.
floppy: This group can be used locally to give a set of users access to a floppy drive and other removable (non-optical) drives (like USB flash drives). Starting with Debian 8 (Jessie) it is not used anymore for USB and flash memories.
staff: Allows users to add local modifications to the system (/usr/local) without needing root privileges (note that executables in /usr/local/bin are in the PATH variable of any user, and they may “override” the executables in /bin and /usr/bin with the same name). Compare with group “adm”, which is more related to monitoring/security.
disk: Raw access to disks. Mostly equivalent to root access.
partition
Plug in the storage device. Look for the attached disk device.
dmesg
[598127.074709] sd 26:0:0:0: [sde] Attached SCSI removable disk
[618067.958840] usb 3-2: new high-speed USB device number 19 using xhci_hcd
[618068.087458] usb 3-2: New USB device found, idVendor=0781, idProduct=5530
[618068.087462] usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[618068.087464] usb 3-2: Product: SanDisk Cruzer
[618068.087466] usb 3-2: Manufacturer: SanDisk
[618068.087468] usb 3-2: SerialNumber: 1738000A80108BA7
[618068.087937] usb-storage 3-2:1.0: USB Mass Storage device detected
[618068.088052] scsi27 : usb-storage 3-2:1.0
[618069.088024] scsi 27:0:0:0: Direct-Access SanDisk SanDisk Cruzer 8.02 PQ: 0 ANSI: 0 CCS
[618069.088534] sd 27:0:0:0: Attached scsi generic sg6 type 0
[618069.088796] sd 27:0:0:0: [sdg] 7913471 512-byte logical blocks: (4.05 GB/3.77 GiB)
[618069.088946] sd 27:0:0:0: [sdg] Write Protect is off
[618069.088951] sd 27:0:0:0: [sdg] Mode Sense: 45 00 00 08
[618069.089123] sd 27:0:0:0: [sdg] No Caching mode page found
[618069.089131] sd 27:0:0:0: [sdg] Assuming drive cache: write through
[618069.093609] sdg: sdg1
[618069.094681] sd 27:0:0:0: [sdg] Attached SCSI removable disk
So [618069.093609] sdg: sdg1
mount
/dev/sdg1 on /media/craig/MP3_1 type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=1000,fmask=0022,dmask=0077,codepage=437,iocharset=utf8,shortname=mixed,showexec,utf8,flush,errors=remount-ro,uhelper=udisks2)
My usage
- unmount with thunar
- as root: gparted /dev/sdg
format
File information
List jpg file names and create date
List jpg file names and create date
ls *JPG
|xargs identify -verbose
|egrep Image:
|date:create
| paste -sd ' \n'
>~/tmp/pics.txt
Image: DSC_0038.JPG date:create: 2015-11-15T18:52:14-07:00
Image: DSC_0039.JPG date:create: 2015-11-15T18:52:28-07:00
Image: DSC_0040.JPG date:create: 2015-11-15T18:53:00-07:00
Image: DSC_0041.JPG date:create: 2015-11-15T18:53:40-07:00
Image: DSC_0042.JPG date:create: 2015-11-15T18:54:42-07:00
Image: DSC_0043.JPG date:create: 2015-11-15T18:55:08-07:00
Image: DSC_0044.JPG date:create: 2015-11-15T18:55:32-07:00
Packages
apt-cache search freecad
dpkg --get-selections
To see all the files the package installed onto your system, do this:
dpkg-query -L
To see the files a .deb file will install
dpkg-deb -c
To see the files contained in a package NOT installed, do this once (if you haven't installed apt-file already:
sudo apt-get install apt-file
sudo apt-file update
then
apt-file list
## android ptp mtp
### jmtpfs
sudo apt-get install jmtpfs
sudo mkdir /media/craig/mtp
sudo chown craig:craig /media/craig/mtp
connect phone with usb
jmtpfs /media/craig/mtp
mount
...
jmtpfs on /media/craig/mtp type fuse.jmtpfs (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)
sudo umount /media/craig/mtp
Printers
lpstat -s
system default destination: OfficeLaserPrinter
device for EPSON_Stylus_Photo_R320: usb://EPSON/Stylus%20Photo%20R320?serial=L27P10501230231030&interface=1
device for OfficeLaserPrinter: dnssd://Brother%20HL-5250DN%20series._pdl-datastream._tcp.local/
lpstat -o
view all outstanding print jobs
lprm -
Kill all print jobs
cancel -a printer
Printer info in cups
OfficeLaserPrinter (Idle, Accepting Jobs, Shared, Server Default)
Description: Brother HL-5250DN Laser Printer
Location: Bathroom hall
Driver: Brother HL-5250DN BR-Script3 (grayscale, 2-sided printing)
Connection: dnssd://Brother%20HL-5250DN%20series._pdl-datastream._tcp.local/
Defaults: job-sheets=none, none media=iso_a4_210x297mm sides=one-sided
# imap
delog.wordpress.com article
openssl s_client -crlf -connect imap.gmail.com:993
tag login user@gmail.com password
tag LIST "" "*"
cyberciti.biz/faq
How to use sed to find and replace text in files in Linux / Unix shell
Thumb Drive Photo01
Kinston DataTraveler 100 G3
Format ext2
dmesg showed sdd sdd1
parted /dev/sdd
rm 1
mklabel gpt
quit
fdisk /dev/sdd
n - took defaults
p
Disk /dev/sdd: 14.4 GiB, 15502147584 bytes, 30277632 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 1949B270-86FC-4340-A94F-230556CF35D7
Device Start End Sectors Size Type
/dev/sdd1 2048 30277598 30275551 14.4G Linux filesystem
mkfs.ext2 -L photo01 /dev/sdd1
gparted
close when done
blkid /dev/sdd1
/dev/sdd1: LABEL="photo01" UUID="072a7689-e02c-4b3e-a788-0629f5c55527" TYPE="ext2" PARTUUID="fb297370-b451-42a7-b529-6a5f13701bd3"
mke2fs -L photo01 -t ext2 /dev/sdd1
imagemagick
pull page images out of an image pdf file
convert -density 150 input.pdf -quality 90 output.jpg
convert jpg file to pdf
convert -density 150 output.pdf -quality 90 output.pdf
meldmerge.org
Meld
Meld is a visual diff and merge tool targeted at developers. Meld helps
you compare files, directories, and version controlled projects. It
provides two- and three-way comparison of both files and directories,
and has support for many popular version control systems.
Meld helps you review code changes and understand patches. It might even
help you to figure out what is going on in that merge you keep avoiding.