rename

can be used to rename multiple files. In the past it was available out of the box, but in Ubuntu 19.04 it is not installed by default, and probably you won't need it - use mv, or use GUI file manager (e.g., Nautilus), etc. Of course, if you really need to perform some non-trivial renaming operation on a large number of files, then:

sudo apt install rename

It looks like there are several versions of rename with different syntax. The version I've installed turned to be a PERL script /usr/bin/file-rename. I say, before you try smth with this program, read manual, or at least run:

rename --help

The syntax is a little bit confusing for a program named rename:

rename [options] perlexpr files

or

rename [options] 's/expr/repl/' files

It's supposed to rename the specified file(s) by replacing the first occurrence of expr in their name with repl. Both expression and replacement are PERL regex.

rename 'y/A-Z/a-z/' *

convert all filenames in the curr dir to lowercase;

rename 's/\.jade$/\.pug/' *.jade

change file extension from .jade to .pug for all matching files (*.jade) in the curr dir;

rename 's/\.bak$//' *.bak

strip the .bak ext from all matching files;

Options

-h, --help

-V, --version

-v, --verbose

-0, --null

use \0 as record separator when reading from stdin;

-d, --filename, --nopath, --nofullpath

do not rename directories, only rename filename components of the full path;

-e	expression: code to act on filenames; may be repeated to build up code (like "perl -e"); without this option the first arg is used as code;
-E	statement: code to act on filenames; like prev, but terminated with ';'

-f, --force

overwrite existing files;

-n, --no-act, or maybe --nono

show what will be done, but do not make any changes (add -v for details);

--path, --fullpath

rename full path including any dir components (default);

Some versions of rename use these options:

-i, --interactive

ask before overwriting existing files;

-o, --no-overwrite

do not overwrite existing files; if --symlink is active, do not overwrite symlinks pointing to existing targets;

-s, --symlink

do not rename a symlink, rename its target;

renice

alters the scheduling priority of one or more running processes.

renice pri [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]

Negative pri increases priority, positive - decreases. By default the processes are specified by PID. -g causes all processes in the specified process group to be affected, -u causes all processes of the specified user to be affected.

Superuser can ~ any process and change priority in the range from PRIO_MIN (-20) to PRIO_MAX (20). Other users can only control their own processes, and the available range is from 0 to 20.

renice +15 1234

slow down the process with PID = 1234;

renice +20 -u alex

slow down all processes of alex;

rm

removes files and directories, though does not remove dirs by default.

rm message2.txt

remove file message2.txt;

rm -- -f

remove file with an unusual name -f;

rm ./-f

same as previous;

rm -r install

remove dir install recursively;

rm -f *

remove all files, never ask;

rm -d temp1

unlink directory temp1;

rm [options] file ...

Options

--help    --version    -v    --verbose

-d, --dir

remove empty directories;

-f, --force

never prompt, ignore non-existent files and arguments;

-i	prompt before every removal;
-I	prompt once before removing more than three files, or when removing recursively;

--interactive[=never|once|always]

prompt before removal: never is never, once is like -I, always (default) is like -i;

--one-file-system

when removing a hierarchy recursively, skip any dir that is on a file system different from that of the corresponding cmdline arg;

--no-preserve-root

do not treat '/' specially;

--preserve-root

do not remove '/' (default);

-r, -R, --recursive

remove dirs and their contents recursively;

rmdir

removes empty directories.

rmdir -p temp/misc/work

remove dir work, then try to remove dirs misc and temp;

rmdir [options] dir ...

Options

--help    --version    -v    --verbose

-p, --parents

remove dir, then try to remove each dir component of that path name;

--ignore-fail-on-non-empty

ignore failures that happen because dirs are not empty;

route

Deprecated

manipulates the kernel's IP routing tables (mainly to set up the static routes). When add or del are used, ~ modifies kernel table, otherwise, displays current contents.

route -n

show routing table using numerical addresses;

route add -net 127.0.0.0

add the normal loopback entry, using netmask 255.0.0.0 and associated with lo device (assuming it was previously set up with ifconfig);

route add -host 192.168.12.190 dev eth0

add route to the host 192.168.12.190 via eth0;

route add -net 192.168.12.0
netmask 255.255.255.0 gw 192.168.4.250

add a route to the network 192.168.12.0/24 via the gateway 192.168.4.250;

route del default gw 192.168.0.247

remove default gateway 192.168.0.247;

route add default gw 192.168.0.254

add default gateway 192.168.0.254;

route add -net 10.0.0.0 netmask 255.0.0.0 reject

install a rejecting route for the private network 10.0.0.0;

Options

-h    --help    -V    --version    -v    --verbose

-A family

use the specified address family: inet (default), inet6, ax25, ipx, .. (for a list of currently supported families run route --help);

-C	operate on the kernel’s routing cache;
-F	operate on the kernel’s FIB (Forwarding Information Base) routing table (default);
-e	use netstat format to display the routing table;

-gw gateway

route packets via a specified gateway (usually you have to set up a static route to this gateway first);

-host

the target is a host;

-net

the target is a net;

-netmask mask

when adding a network route use the specified netmask;

-n	show numerical addresses;

add

add new route;

del

delete a route;

dev iface

force route to be associated with the specified dev;

metric n

set the metric field in the routing table;

mss n

set TCP MSS (Maximum Segment Size) for connections over this route to n bytes (default is MTU minus headers);

Output

Destination	the destination network or host;
Gateway	the gateway address or * if none set;
Genmask	the netmask for the destination net; 255.255.255.255 for host destination, 0.0.0.0 for the default route;
Flags	U route is up; H target is a host; G use gateway; R reinstate route for dynamic routing; D dynamically installed by daemon or redirect; M modified from routing daemon or redirect; A installed by addrconf; C cache entry; ! reject route;
Metric	the distance to the target (in hops);
Ref	number of references to this route;
Use	count of lookups for the route;
Iface	interface to which packets for this route will be sent;

rpm

(Red Hat Package Manager) is used to install, update, remove (erase), query, verify and build individual software packages.

rpm -i foobar-1.0-1.i386.rpm

install package foobar-1.0-1.i386.rpm;

rpm -U --force foobar-1.0-1.i386.rpm

upgrade package foobar... that was installed earlier;

rpm -Uvh postfix-XXXX.rpm

upgrade package postfix-XXXX (use verbose mode and show progress marks);

rpm -e foobar-1.0.0.i386

remove package foobar...;

rpm -Va

check if some of installed files are missing;

rpm -qa

list all installed packages;

rpm -qa | grep openoffice

list all installed packages related to OpenOffice;

rpm -qf /usr/X11R6/bin/xjewel

find what package this file belongs to;

rpm -qpi koules-1.2-2.i386.rpm

report what is this package for;

rpm -qpl koules-1.2-2.i386.rpm

list files this package is going to install;

rpm --import http://freshrpms.net/packages/RPM-GPG-KEY.txt

import GnuPG public key from freshrpms.net;

A package includes a file archive + metadata (helper scripts, file attributes, package description). There are 2 types of packages: binary and source.

rpm {-i | --install} [options] package

rpm {-U | --upgrade} [options] package

rpm {-F | --freshen} [options] package

rpm {-e | --erase} [options] package

rpm {-q | --query} [select_opts] [query_opts]

rpm {-V | --verify} [select_opts] [verify_opts]

rpm --initdb [-v] [--dbpath dir] [--root dir]

create a new RPM database;

rpm --rebuilddb [-v] [--dbpath dir] [--root dir]

rebuild database indices from the installed pkg headers;

There are also: Uninstall, Signature Check, Resign, Add Signature, Set Owners / Groups, Show Query-tags, Show Configuration.

Options

-?    --help    --version    -v    --verbose

--dbpath dir

use the database in dir rather then the default path (/var/lib/rpm);

--pipe cmd

pipe the output of ~ to the command cmd;

--quiet

quiet mode (only error message are displayed);

--rcfile list

each of the files in the colon-separated list is read sequentially for configuration info; the default is:

/usr/lib/rpm/rpmrc;

/usr/lib/rpm/red-hat/rpmrc;

/etc/rpmrc/:~/.rpmrc;

--root dir

use the filesystem tree rooted at dir for all ops;

Install / Upgrade options

--install is appropriate, if the package is not installed. Otherwise, use --upgrade, which installs a newer version and removes all other versions. --freshen installs only if an earlier version exists.

--excludedocs

don't install any files which are marked as documentation (manpages, texinfo, etc);

--force, --replacepkgs, --replacefiles

install the pkgs even if they replace files from other, already installed, pkgs;

-h, --hash

print 50 hash marks as the package archive is unpacked (use with -v, --verbose);

--ignoresize

don't check disk space before installation;

--ignorearch

install/upgrade even if the architectures of the binary package and host don't match;

--ignoreos

install/upgrade even if the operating systems of the binary package and host don't match;

--nodeps

don't check dependencies before installation;

--nodigest

don't verify package or header digest;

--nosignature

don't verify package or header signatures;

--oldpackage

allow to replace a newer pkg with an older;

--prefix newpath

for relocatable binary pkgs, translate all file paths that start with the installaion prefix in the pkg relocation hint(s) to newpath;

--test

do not install, just check and report potential conflicts;

Remove (erase) options

--allmatches

remove all versions of the package;

--nodeps

don't check dependencies before uninstalling;

--test

do not really uninstall, just simulate the procedure;

Query options

-a, --all

query all installed packages;

-f file, --file file

find what package this file belongs to;

--whatprovides capability

query all packages that provide the specified capability;

--whatrequires capability

query all packages that require the specified capability for proper functioning;

Query options (specific package)

-i, --info

display package info (name, version, description);

-l, --list

list files in the package;

-R, --requires

list packages on which this pkg depends;

-s, --state

display the states of the files in the package; the states are: normal / not installed / replaced;

--changelog

display change info on this package;

--filesbypkg

list all files in each selected package;

--dump

dump file info in a special format: path size mtime md5sum mode owner group isconfig isdoc rdev symlink;

--provides

list the capabilities this package provides;

--scripts

list the package specific scriplets that are used as part of the installation / uninstallation processes;

Verify options

Verification procedure compares info about the installed files with info about the files taken from the package metadata stored in the rpm database.

--nodeps

don't verify dependencies;

--nodigest

don't verify package or header digest;

--nofiles

don't verify file attributes;

--nosignature

don't verify package or header signatures;

--nosize, --nouser, --nogroup, --nomtime, --nomode

don't verify the corresponding file attribute;