xxd not doing anything on alpine linux - alpine-linux

I'm trying to use xxd to follow a tutorial but it's not printing anything from the Alpine Linux container that I'm trying to run it in.
I am running: xxd -ps -c 1000 <valid-file-path>. When I do this, it just prints out the usage instructions:
~ # xxd -ps -c 1000 $FILE_PATH
BusyBox v1.31.1 () multi-call binary.
Usage: xxd [OPTIONS] [FILE]
Hex dump FILE (or stdin)
-g N Bytes per group
-c N Bytes per line
-p Show only hex bytes, assumes -c30
-l LENGTH Show only first LENGTH bytes
-s OFFSET Skip OFFSET bytes
I seem to be calling it correctly according to the printed usage instructions. What am I doing wrong?

Alpine comes with busybox, which is a smaller version of the utilities that come with say, Ubuntu, GNU Coreutils. If you've heard people say "GNU/Linux", this is what they're referring to - many of the utilities you use on the command line were written by the Free Software Foundation.
Busybox xxd doesn't have the -ps option because it was rewritten to be smaller. It prints out the usage instructions because -ps is not valid. If you run this on macos or linux, you'll get different versions of the original xxd.
As you've found, apk add xxd will install this "original" xxd.

Related

How can I get process command line from PowerShell Core on Ubuntu?

I'm on a Ubuntu 18.04 server. I know the full command line information can be grabbed by ps auxww. For example, by running ps auxww, I know the command /usr/local/bin/my-program -parameter :8888 is running. How can I get the same info from PowerShell? I searched around and all the info is about how to get the command line info on Windows.
On Ubuntu 18.04 PowerShell,
did you try ps -a -F. It should give the details you are looking for.
if need specific details about the running/all processes try with more options with
ps --help all or ps --help output commands
PS> ps --help output
Usage:
ps [options]
Basic options:
-A, -e all processes
-a all with tty, except session leaders
a all with tty, including other users
-d all except session leaders
-N, --deselect negate selection
r only running processes
T all processes on this terminal
x processes without controlling ttys
Output formats:
-F extra full
-f full-format, including command lines
f, --forest ascii art process tree
-H show process hierarchy
-j jobs format
j BSD job control format
-l long format
l BSD long format
-M, Z add security data (for SELinux)
-O <format> preloaded with default columns
O <format> as -O, with BSD personality
-o, o, --format <format>
user-defined format
s signal format
u user-oriented format
v virtual memory format
X register format
-y do not show flags, show rss vs. addr (used with -l)
--context display security context (for SELinux)
--headers repeat header lines, one per page
--no-headers do not print header at all
--cols, --columns, --width <num>
set screen width
--rows, --lines <num>
set screen height
--help <simple|list|output|threads|misc|all>
display help and exit
For more details see ps(1).

Determining throughput from pcap containing flow records

I have a single packet capture (acquired via tcpdump) that contains flow records between an exporter and a collector.
I want to determine throughput across a given interface using the bytes (octets) field in the v9 record. I have filtered down to the network that I want like so:
tshark -r input.pcap -Y "ip.src == X.X.X.X" -F pcap -w filtered.pcap
I further filtered to the interface that I needed like so:
tshark -r filtered.pcap -Y "cflow.inputint == Y" -F pcap -w filtered2.pcap
I'm lost after that. Is there a better tool to aggregate across the flows to get throughput?
Any help would be greatly appreciated!
You may try to print netflow fields and then process the results.
For example:
tshark -T fields -e cflow.version -e cflow.srcaddr -e cflow.dstaddr -e cflow.octets -e cflow.timedelta -e cflow.abstimestart
Field names are visible in wireshark status bar when you select packet details.
Better option:
install or compile https://github.com/phaag/nfdump with --enable-readpcap flag.
process your pcap nfcapd -f <path to your pcap file> -l <path to output directory> -T all
count statistics nfdump -o extended -r <path to output directory>

scripting with sed and wget in Windows

I have some issue with Internet connectivity in a LAN. Some users are happy and some complain about the Internet speed. So I came with an idea to install software on three different PCs and try to download/upload a file at the same time and record the speed. Then I will able to create a graph with the data that I acquired.
I am looking for a way to download several files and check the speed. I found How to grep download speed from wget output? for wget and sed. How do I use wget -O /dev/null http://example.com/index.html 2>&1 | sed -e 's|^.*(\([0-9.]\+ [KM]B/s\)).*$|\1|' for Windows? I already installed wget and sed on Windows.
All PCs running Windows XP or 7.
Sed isn't different on Windows. The only difference is, that /dev/null doesn't exist on Windows, but NUL.
So:
wget -O NUL http://example.com/index.html 2>&1 | sed -e 's|^.*(\([0-9.]\+ [KM]B/s\)).*$|\1|'
should work on Windows. I'm not 100% sure about 2>&1 - maybe there is some other syntax to use.

Search a text in selected coding system in file hierarchy

I want to search for text in a specified coding system (cp1251/UTF-8/UTF-16-le/iso-8859-4, etc) in a file hierarchy.
For example I have source code in cp1251 coding and I run Debian with system coding UTF-8. grep or Midnight Commander perform searches in UTF-8 coding. So I can not find Russian words.
Preferred solutions will use standard POSIX or GNU command line utilities (like grep).
MC or Emacs solution also appreciated.
I tried:
$ grep `echo Привет | iconv -f cp1251 -t utf-8` *
but this command does not show results sometimes.
The command you proposed outputs the string Привет, then pipes the result of that output to iconv and applies grep to the result of iconv. That is not what you want. What you want is this:
find . -type f -printf "iconv -f cp1251 -t utf-8 '%p' | grep --label '%p' -H 'Привет'\n" | sh
This applies iconv, followed by grep, to every file below the current directory.
But note that this assumes that all of your files are in CP1251. It will fail if only some of them are. In that case you'd first have to write a program that detects the encoding of a file and then applies iconv only if necessary.
From the command line:
LANG=ru_RU.cp1251 grep Привет *

Multiple simultaneous downloads using Wget?

I'm using wget to download website content, but wget downloads the files one by one.
How can I make wget download using 4 simultaneous connections?
Use the aria2:
aria2c -x 16 [url]
# |
# |
# |
# ----> the number of connections
http://aria2.sourceforge.net
Wget does not support multiple socket connections in order to speed up download of files.
I think we can do a bit better than gmarian answer.
The correct way is to use aria2.
aria2c -x 16 -s 16 [url]
# | |
# | |
# | |
# ---------> the number of connections here
Official documentation:
-x, --max-connection-per-server=NUM: The maximum number of connections to one server for each download. Possible Values: 1-16 Default: 1
-s, --split=N: Download a file using N connections. If more than N URIs are given, first N URIs are used and remaining URLs are used for backup. If less than N URIs are given, those URLs are used more than once so that N connections total are made simultaneously. The number of connections to the same host is restricted by the --max-connection-per-server option. See also the --min-split-size option. Possible Values: 1-* Default: 5
Since GNU parallel was not mentioned yet, let me give another way:
cat url.list | parallel -j 8 wget -O {#}.html {}
I found (probably)
a solution
In the process of downloading a few thousand log files from one server
to the next I suddenly had the need to do some serious multithreaded
downloading in BSD, preferably with Wget as that was the simplest way
I could think of handling this. A little looking around led me to
this little nugget:
wget -r -np -N [url] &
wget -r -np -N [url] &
wget -r -np -N [url] &
wget -r -np -N [url]
Just repeat the wget -r -np -N [url] for as many threads as you need...
Now given this isn’t pretty and there are surely better ways to do
this but if you want something quick and dirty it should do the trick...
Note: the option -N makes wget download only "newer" files, which means it won't overwrite or re-download files unless their timestamp changes on the server.
Another program that can do this is axel.
axel -n <NUMBER_OF_CONNECTIONS> URL
For baisic HTTP Auth,
axel -n <NUMBER_OF_CONNECTIONS> "user:password#https://domain.tld/path/file.ext"
Ubuntu man page.
A new (but yet not released) tool is Mget.
It has already many options known from Wget and comes with a library that allows you to easily embed (recursive) downloading into your own application.
To answer your question:
mget --num-threads=4 [url]
UPDATE
Mget is now developed as Wget2 with many bugs fixed and more features (e.g. HTTP/2 support).
--num-threads is now --max-threads.
I strongly suggest to use httrack.
ex: httrack -v -w http://example.com/
It will do a mirror with 8 simultaneous connections as default. Httrack has a tons of options where to play. Have a look.
As other posters have mentioned, I'd suggest you have a look at aria2. From the Ubuntu man page for version 1.16.1:
aria2 is a utility for downloading files. The supported protocols are HTTP(S), FTP, BitTorrent, and Metalink. aria2 can download a file from multiple sources/protocols and tries to utilize your maximum download bandwidth. It supports downloading a file from HTTP(S)/FTP and BitTorrent at the same time, while the data downloaded from HTTP(S)/FTP is uploaded to the BitTorrent swarm. Using Metalink's chunk checksums, aria2 automatically validates chunks of data while downloading a file like BitTorrent.
You can use the -x flag to specify the maximum number of connections per server (default: 1):
aria2c -x 16 [url]
If the same file is available from multiple locations, you can choose to download from all of them. Use the -j flag to specify the maximum number of parallel downloads for every static URI (default: 5).
aria2c -j 5 [url] [url2]
Have a look at http://aria2.sourceforge.net/ for more information. For usage information, the man page is really descriptive and has a section on the bottom with usage examples. An online version can be found at http://aria2.sourceforge.net/manual/en/html/README.html.
wget cant download in multiple connections, instead you can try to user other program like aria2.
use
aria2c -x 10 -i websites.txt >/dev/null 2>/dev/null &
in websites.txt put 1 url per line, example:
https://www.example.com/1.mp4
https://www.example.com/2.mp4
https://www.example.com/3.mp4
https://www.example.com/4.mp4
https://www.example.com/5.mp4
try pcurl
http://sourceforge.net/projects/pcurl/
uses curl instead of wget, downloads in 10 segments in parallel.
They always say it depends but when it comes to mirroring a website The best exists httrack. It is super fast and easy to work. The only downside is it's so called support forum but you can find your way using official documentation. It has both GUI and CLI interface and it Supports cookies just read the docs This is the best.(Be cureful with this tool you can download the whole web on your harddrive)
httrack -c8 [url]
By default maximum number of simultaneous connections limited to 8 to avoid server overload
use xargs to make wget working in multiple file in parallel
#!/bin/bash
mywget()
{
wget "$1"
}
export -f mywget
# run wget in parallel using 8 thread/connection
xargs -P 8 -n 1 -I {} bash -c "mywget '{}'" < list_urls.txt
Aria2 options, The right way working with file smaller than 20mb
aria2c -k 2M -x 10 -s 10 [url]
-k 2M split file into 2mb chunk
-k or --min-split-size has default value of 20mb, if you not set this option and file under 20mb it will only run in single connection no matter what value of -x or -s
You can use xargs
-P is the number of processes, for example, if set -P 4, four links will be downloaded at the same time, if set to -P 0, xargs will launch as many processes as possible and all of the links will be downloaded.
cat links.txt | xargs -P 4 -I{} wget {}
I'm using gnu parallel
cat listoflinks.txt | parallel --bar -j ${MAX_PARALLEL:-$(nproc)} wget -nv {}
cat will pipe a list of line separated URLs to parallel
--bar flag will show parallel execution progress bar
MAX_PARALLEL env var is for maximum no of parallel download, use it carefully, default here is current no of CPUs
tip: use --dry-run to see what will happen if you execute command.
cat listoflinks.txt | parallel --dry-run --bar -j ${MAX_PARALLEL} wget -nv {}
make can be parallelised easily (e.g., make -j 4). For example, here's a simple Makefile I'm using to download files in parallel using wget:
BASE=http://www.somewhere.com/path/to
FILES=$(shell awk '{printf "%s.ext\n", $$1}' filelist.txt)
LOG=download.log
all: $(FILES)
echo $(FILES)
%.ext:
wget -N -a $(LOG) $(BASE)/$#
.PHONY: all
default: all
Consider using Regular Expressions or FTP Globbing. By that you could start wget multiple times with different groups of filename starting characters depending on their frequency of occurrence.
This is for example how I sync a folder between two NAS:
wget --recursive --level 0 --no-host-directories --cut-dirs=2 --no-verbose --timestamping --backups=0 --bind-address=10.0.0.10 --user=<ftp_user> --password=<ftp_password> "ftp://10.0.0.100/foo/bar/[0-9a-hA-H]*" --directory-prefix=/volume1/foo &
wget --recursive --level 0 --no-host-directories --cut-dirs=2 --no-verbose --timestamping --backups=0 --bind-address=10.0.0.11 --user=<ftp_user> --password=<ftp_password> "ftp://10.0.0.100/foo/bar/[!0-9a-hA-H]*" --directory-prefix=/volume1/foo &
The first wget syncs all files/folders starting with 0, 1, 2... F, G, H and the second thread syncs everything else.
This was the easiest way to sync between a NAS with one 10G ethernet port (10.0.0.100) and a NAS with two 1G ethernet ports (10.0.0.10 and 10.0.0.11). I bound the two wget threads through --bind-address to the different ethernet ports and called them parallel by putting & at the end of each line. By that I was able to copy huge files with 2x 100 MB/s = 200 MB/s in total.
Call Wget for each link and set it to run in background.
I tried this Python code
with open('links.txt', 'r')as f1: # Opens links.txt file with read mode
list_1 = f1.read().splitlines() # Get every line in links.txt
for i in list_1: # Iteration over each link
!wget "$i" -bq # Call wget with background mode
Parameters :
b - Run in Background
q - Quiet mode (No Output)
If you are doing recursive downloads, where you don't know all of the URLs yet, wget is perfect.
If you already have a list of each URL you want to download, then skip down to cURL below.
Multiple Simultaneous Downloads Using Wget Recursively (unknown list of URLs)
# Multiple simultaneous donwloads
URL=ftp://ftp.example.com
for i in {1..10}; do
wget --no-clobber --recursive "${URL}" &
done
The above loop will start 10 wget's, each recursively downloading from the same website, however they will not overlap or download the same file twice.
Using --no-clobber prevents each of the 10 wget processes from downloading the same file twice (including full relative URL path).
& forks each wget to the background, allowing you to run multiple simultaneous downloads from the same website using wget.
Multiple Simultaneous Downloads Using curl from a list of URLs
If you already have a list of URLs you want to download, curl -Z is parallelised curl, with a default of 50 downloads running at once.
However, for curl, the list has to be in this format:
url = https://example.com/1.html
-O
url = https://example.com/2.html
-O
So if you already have a list of URLs to download, simply format the list, and then run cURL
cat url_list.txt
#https://example.com/1.html
#https://example.com/2.html
touch url_list_formatted.txt
while read -r URL; do
echo "url = ${URL}" >> url_list_formatted.txt
echo "-O" >> url_list_formatted.txt
done < url_list.txt
Download in parallel using curl from list of URLs:
curl -Z --parallel-max 100 -K url_list_formatted.txt
For example,
$ curl -Z --parallel-max 100 -K url_list_formatted.txt
DL% UL% Dled Uled Xfers Live Qd Total Current Left Speed
100 -- 2512 0 2 0 0 0:00:01 0:00:01 --:--:-- 1973
$ ls
1.html 2.html url_list_formatted.txt url_list.txt