I can't figure out how to print (unix tool) versions within a BusyBox container:
$ docker run -it quay.io/quay/busybox:latest
$ awk --version
awk: unrecognized option `--version'
BusyBox v1.32.0 (2020-08-31 17:40:13 UTC) multi-call binary.
Usage: awk [OPTIONS] [AWK_PROGRAM] [FILE]...
-v VAR=VAL Set variable
-F SEP Use SEP as field separator
-f FILE Read program from FILE
-e AWK_PROGRAM
$ cut --version
cut: unrecognized option `--version'
BusyBox v1.32.0 (2020-08-31 17:40:13 UTC) multi-call binary.
Usage: cut [OPTIONS] [FILE]...
Print selected fields from each input FILE to stdout
-b LIST Output only bytes from LIST
-c LIST Output only characters from LIST
-d CHAR Use CHAR instead of tab as the field delimiter
-s Output only the lines containing delimiter
-f N Print only these fields
-n Ignored
Any suggestions? Many mulled containers are built on top of BusyBox, best I get on top of this.
Thanks
busybox is a single program which acts as one of various tools depending on what name was used to call it. As you can see in the question, it shows its version as BusyBox v1.32.0.
Check which tools are (symbolic) links to busybox. All these are the same program and therefore have the same version, so you might only need the version of busybox and a list of commands linked to it.
According to https://unix.stackexchange.com/q/15895/330217 the best way to display the version of busybox is
busybox | head -1
Related
I have this alias in my .zshrc file:
alias rmcons="docker rm -f $(docker ps -aq)"
But after trying to execute it, it removes only one container and then it prints
$rmcons
ef8197f147fb
zsh: command not found: c2ea2673f9e4
zsh: command not found: 4603059f1618
zsh: command not found: 40ad60328595
How can I remove all containers that docker ps -aq shows?
You need to use single quotes ('') instead of double quotes ("").
alias rmcons='docker rm -f $(docker ps -aq)'
If you use double quotes, than the command substitution $(docker ps -aq) will be evaluated when you define the alias. In your example this was equivalent to
alias rmcons="docker rm -f ef8197f147fb
c2ea2673f9e4
4603059f1618
40ad60328595"
As the newlines are command separators (like ;) this alias is substituted by four commands: docker rm -f ef8197f147fb, c2ea2673f9e4, 4603059f1618 and 40ad60328595. The last three of which do not exist on your system, hence "command not found". It also means that the same output of docker ps -aq - as it was on alias definiton - will be used and not as it would be when running the alias.
On the other hand, if you use single quotes, the alias will actually substituted by the exact command you defined: docker rm -f $(docker ps -aq). Although docker ps -aq will still return output with newlines, these newlines are now only parsed word separators between arguments.
Warning: untested. I don't use/have docker.
I think you should serialize the output first "escaping" the new lines.
You might also use the for loop, trying:
for id in `docker ps -aq`; do docker rm -f $id; done
Note the backquotes to parse the command's output.
You can also directly use $() instead of its shortcut backquote.
I recommend to test with echo first instead of removing with rm:
for id in `docker -ps -aq`; do echo rm -f $id; done
, and to use the rm with its -i switch to prompt for confirmation before deleting.
I hope docker's rm subcommand has one.
I'm writing a utility program in Common Lisp and building it with Clozure CL; I would like to be able to use the command-line option -d with the program, but for some reason this particular option won't make it through to (ccl::command-line-arguments). Here is a minimal example:
(defun main ()
(format t "~s~%" (ccl::command-line-arguments))
(quit))
I compiled with
(save-application "opts"
:toplevel-function 'main
:prepend-kernel t)
and here's some sample output:
~/dev/scratch$ ./opts -c -a -e
("./opts" "-c" "-a" "-e")
~/dev/scratch$ ./opts -c -d -e
("./opts" "-c" "-e")
~/dev/scratch$ ./opts -b --frogs -c -d -e -f -g -h --eye --jay -k -l
("./opts" "--frogs" "-c" "-e" "-f" "-g" "-h" "--eye" "--jay" "-k" "-l")
The -b and -d options appear to be getting lost. The documentation on command line arguments for ccl isn't very helpful. I thought maybe because ccl itself takes -b as an argument, that option might have gotten eaten for some reason, but it doesn't take -d (which is eaten), and it does take -e and -l which aren't. Nothing on saving applications seemed helpful.
I'm pretty sure it's Clozure-specific (and not, say, the shell eating them), because other stuff seems to be getting all the arguments:
#!/usr/bin/python
import sys
print sys.argv
yields
~/dev/scratch$ ./opts.py -a -b -c -d -e
['./opts.py', '-a', '-b', '-c', '-d', '-e']
and
#!/bin/bash
echo "$#"
gives
~/dev/scratch$ ./opts.sh -a -b -c -d -e
-a -b -c -d -e
This is all taking place on lubuntu 15.10 with bash as the shell.
If anyone could shed some light on why this is happening or how I can end up with all my command-line switches, I'd be appreciative.
Thanks.
According to the source code of the 1.11 release, -b and -d are options used by the lisp kernel.
Since I'm unsure about licence issues, I just provide the link to the relevant file: http://svn.clozure.com/publicsvn/openmcl/release/1.11/source/lisp-kernel/pmcl-kernel.c
Command line arguments are processed in the function process_options, where for options -b (--batch) and -d (--debug) - among others - a variable num_elide is set to 1. A bit further down, this leads to overwriting the option with the following argument (argv[k] = argv[j];).
The code also shows a possible fix: Supply -- (two dashes) once as argument before -b or -d. When above function encounters a -- it stops processing the rest of the arguments, thus leaving them unchanged to be possibly taken up into "lisp world" shortly after.
Turns out this has already been solved at SO before:
https://stackoverflow.com/a/5522169/1116364
I am trying to find the cpu utilization of a process from top.So before that I had to test the below command
top -b -c -d1 -n2
I am using -c option to print the full command name as the process name gets truncated without -c.
No when I run this as nohup sh test.sh & ,the output nohup.out contains truncated process name and because of which I am not able to grep on the process name
159 neutron 30 0 127620 22765 5479 S 0.0 0.6 399:02.56 /usr/bin/p+t
But when I run this as sh test.sh & its printing the full command name to terminal.
Why is the full command name not printed in spite of using -c in batch mode for top command ?
Whats the difference between command name with -c enabled and process name ?
Or to phrase it the process name and command name are different and the process name is picked from /proc/pid/status by commands like ps or top?
We can set the COLUMNS environment variable before the top command to increase the available width.
COLUMNS=1000 top -b -c -d1 -n2
The other way would be is to use ps to find the pid's of the processes by their names and specify the format of ps output.This output can be used to feed top to get the cpu usage for the process based on pid.
ps -eo pid,comms,args
comms = command name only and not the args
args = full argument list used to launch the process
Usually, stdout is line-buffered. In other words, as long as your printf argument ends with a newline, you can expect the line to be printed instantly. This does not appear to hold when using a pipe to redirect to tee.
I have a C++ program, a, that outputs strings, always \n-terminated, to stdout.
When it is run by itself (./a), everything prints correctly and at the right time, as expected. However, if I pipe it to tee (./a | tee output.txt), it doesn't print anything until it quits, which defeats the purpose of using tee.
I know that I could fix it by adding a fflush(stdout) after each printing operation in the C++ program. But is there a cleaner, easier way? Is there a command I can run, for example, that would force stdout to be line-buffered, even when using a pipe?
you can try stdbuf
$ stdbuf --output=L ./a | tee output.txt
(big) part of the man page:
-i, --input=MODE adjust standard input stream buffering
-o, --output=MODE adjust standard output stream buffering
-e, --error=MODE adjust standard error stream buffering
If MODE is 'L' the corresponding stream will be line buffered.
This option is invalid with standard input.
If MODE is '0' the corresponding stream will be unbuffered.
Otherwise MODE is a number which may be followed by one of the following:
KB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T, P, E, Z, Y.
In this case the corresponding stream will be fully buffered with the buffer
size set to MODE bytes.
keep this in mind, though:
NOTE: If COMMAND adjusts the buffering of its standard streams ('tee' does
for e.g.) then that will override corresponding settings changed by 'stdbuf'.
Also some filters (like 'dd' and 'cat' etc.) dont use streams for I/O,
and are thus unaffected by 'stdbuf' settings.
you are not running stdbuf on tee, you're running it on a, so this shouldn't affect you, unless you set the buffering of a's streams in a's source.
Also, stdbuf is not POSIX, but part of GNU-coreutils.
Try unbuffer (man page) which is part of the expect package. You may already have it on your system.
In your case you would use it like this:
unbuffer ./a | tee output.txt
The -p option is for pipeline mode where unbuffer reads from stdin and passes it to the command in the rest of the arguments.
You can use setlinebuf from stdio.h.
setlinebuf(stdout);
This should change the buffering to "line buffered".
If you need more flexibility you can use setvbuf.
You may also try to execute your command in a pseudo-terminal using the script command (which should enforce line-buffered output to the pipe)!
script -q /dev/null ./a | tee output.txt # Mac OS X, FreeBSD
script -c "./a" /dev/null | tee output.txt # Linux
Be aware the script command does not propagate back the exit status of the wrapped command.
The unbuffer command from the expect package at the #Paused until further notice answer did not worked for me the way it was presented.
Instead of using:
./a | unbuffer -p tee output.txt
I had to use:
unbuffer -p ./a | tee output.txt
(-p is for pipeline mode where unbuffer reads from stdin and passes it to the command in the rest of the arguments)
The expect package can be installed on:
MSYS2 with pacman -S expect
Mac OS with brew install expect
Update
I recently had buffering problems with python inside a shell script (when trying to append timestamp to its output). The fix was to pass -u flag to python this way:
run.sh with python -u script.py
unbuffer -p /bin/bash run.sh 2>&1 | tee /dev/tty | ts '[%Y-%m-%d %H:%M:%S]' >> somefile.txt
This command will put a timestamp on the output and send it to a file and stdout at the same time.
The ts program (timestamp) can be installed with the moreutils package.
Update 2
Recently, also had problems with grep buffering the output, when I used the argument grep --line-buffered on grep to it stop buffering the output.
If you use the C++ stream classes instead, every std::endl is an implicit flush. Using C-style printing, I think the method you suggested (fflush()) is the only way.
The best answer IMO is grep's --line-buffer option as stated here:
https://unix.stackexchange.com/a/53445/40003
I'm trying to figure out how to install Pear on my Mac (10.6.6).
Not understanding what they're telling me at pear.php.net, I got some code from http://clickontyler.com/blog/2008/01/how-to-install-pear-in-mac-os-x-leopard/
First, I entered curl http://pear.php.net/go-pear > go-pear.php in my terminal.
It resulted in this output
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 88004 100 88004 0 0 47537 0 0:00:01 0:00:01 --:--:-- 59744
What does that all mean? Am I on the right track?
Next, I entered sudo php -q go-pear.php
and it gave me the long output below. In short I have no idea where I am in the installation process. However, I'm pretty sure that I'm not where I'm supposed to be at following the tutorial at http://clickontyler.com/blog/2008/01/how-to-install-pear-in-mac-os-x-leopard/
because the tutorial tells me to select all the default choices, and I don't see any options to select.
The next line of code is asking me to modify the php.ini files and it requires a password so I'm worried about doing it...Can anyone tell me if I'm on the right track?
sudo cp /etc/php.ini.default /etc/php.ini
Usage: php [options] [-f] <file> [--] [args...]
php [options] -r <code> [--] [args...]
php [options] [-B <begin_code>] -R <code> [-E <end_code>] [--] [args...]
php [options] [-B <begin_code>] -F <file> [-E <end_code>] [--] [args...]
php [options] -- [args...]
php [options] -a
-a Run interactively
-c <path>|<file> Look for php.ini file in this directory
-n No php.ini file will be used
-d foo[=bar] Define INI entry foo with value 'bar'
-e Generate extended information for debugger/profiler
-f <file> Parse and execute <file>.
-h This help
-i PHP information
-l Syntax check only (lint)
-m Show compiled in modules
-r <code> Run PHP <code> without using script tags <?..?>
-B <begin_code> Run PHP <begin_code> before processing input lines
-R <code> Run PHP <code> for every input line
-F <file> Parse and execute <file> for every input line
-E <end_code> Run PHP <end_code> after processing all input lines
-H Hide any passed arguments from external tools.
-s Output HTML syntax highlighted source.
-v Version number
-w Output source with stripped comments and whitespace.
-z <file> Load Zend extension <file>.
args... Arguments passed to script. Use -- args when first argument
starts with - or script is read from stdin
--ini Show configuration file names
--rf <name> Show information about function <name>.
--rc <name> Show information about class <name>.
--re <name> Show information about extension <name>.
--ri <name> Show configuration for extension <name>.
php does not have an argument -q. Its also mentioned in go-pear.php (http://pear.php.net/go-pear) itself, but I dont know, what it wants to tell me. However, try
sudo php go-pear.php
and then follow the instructions.
Update:
-q was used, to start the interpreter in "quiet" mode. It seems, that this option does not exists anymore, because php always starts "quiet", but it should not cause an error, anyway. Now make sure you are in the same directory as the file go-pear.php before you call php go-pear.php.
The first part shows that you successfully downloaded the file to go-pear.php.
The second part is showing that -q isn't a valid option. The third part is asking for the root password, since you're doing 'sudo'.
I used this, though I wasn't installing on Mac:
Getting and installing the PEAR package manager