Questions tagged [standard]
The standard tag has no usage guidance.
82
questions
1
vote
2answers
63 views
Is a NEWLINE character at line end required by LSB (Linux Standard Base)?
Both POSIX and SUS (Single UNIX Specification) define a line as
A sequence of zero or more non-<newline> characters plus a terminating <newline> character.
Many distributions are more ...
12
votes
2answers
476 views
What is POSIX awk's stance on null byte in variables/printf?
Is it legal to print null bytes using awk's printf function according to POSIX? The POSIX standard of awk does not seem to explicitly mention it either way. Real world implementations differ in how ...
1
vote
1answer
37 views
Why is it legal to have white space before builtin function in awk?
I am trying to understand how busybox's awk works so I'm looking into the standard and hit weird thing which I do not fully understand why is legal. Standard ( https://pubs.opengroup.org/onlinepubs/...
2
votes
0answers
12 views
RHEL based distros and FHS (and postgres)
Under CentOS, i see postgres config files are located in '/var/lib/...' (instead of '/etc'). In FHS specifications, under '/var/lib' (chapter 5, section 8.1) it is specified:
This hierarchy holds ...
0
votes
0answers
33 views
Is $HOME/.local/bin now the preferred location of user-made binaries and scripts or does $HOME/bin still meant fulfull this role? [duplicate]
When I create my own binaries and executable scripts, is the $HOME/.local/bin the preferred convention or should I still be placing them in $HOME/bin?
Putting them into .local/ would help to de-...
1
vote
2answers
50 views
Why does lvm2 use mixed case UUIDs?
I noticed that lvm2 objects use mixed case UUIDs:
~ # lvdisplay
...
-4
votes
2answers
74 views
Utility dependence in shell
I know that the "layer" architecture of any *nix OS is kernel-shell-utility ("inner to outer").
if we installed say Debian-Server and got some CLI utilities with it,
Should all these utilities work ...
1
vote
0answers
48 views
Why does mtab live in etc? [duplicate]
Something I've never understood with linux is why a status file is stored under /etc. As far as I know /etc/ is for configuration (relatively static) configuration files. But /etc/mtab shows the ...
0
votes
2answers
393 views
Why does Apple care if macOS is officially called UNIX? [closed]
Based on my understanding, if the owners of an OS want their OS to be officially called UNIX, they must get a certification from The Open Group.
macOS version 10.14 Mojave, as well as some (or maybe ...
3
votes
1answer
1k views
WM_CLASS vs WM_INSTANCE?
When I run xprop I get a class string that has two values, one of them i3 calls an instance, the other a class, for example on chromium-browser the xprop utility will return something like this,
...
2
votes
2answers
485 views
Different standards of ELF (SysV vs TIS) and Linux?
There are at least two standards of Executable and Linkable Format
(ELF), one of them
System V Application Binary Interface AMD64 Architecture Processor Supplement (With LP64 and ILP32 Programming ...
4
votes
1answer
642 views
Is Linux considered XSI compliant or largely so?
From APUE
The Single UNIX Speciļ¬cation, a superset of the POSIX.1 standard,
speciļ¬es additional interfaces that extend the functionality provided
by the POSIX.1 speciļ¬cation. POSIX.1 is ...
1
vote
0answers
103 views
Move from single configuration files to .d directories in Linux
Note: I am not asking specifically about rc as in The rc0.d,rc1.d,... directories in /etc
Many guides on the internet and this website remember the days when Linux distributions by default used files ...
0
votes
1answer
59 views
linux + write both standard output and stand error to log and to console
log=/tmp/log.txt
the follwing syntax write all standard output and stand art error to log.txt file
exec > $log 2>&1
what we want is to write both standard output and stand art error to log.txt ...
5
votes
2answers
2k views
Does POSIX standardize the file descriptor numbers?
Does POSIX mandate that stdin is 0, stdout is 1 and stderr is 2 or is this only a convention? Do other systems diverge from that convention or is it a safe assumption?
1
vote
3answers
278 views
Do variables and aliases fall under the same category?
This is a terminology/architecture question.
Some of the most basic implementations for easier control of a system are variables and aliases (and some might add symlinks).
Both variables and ...
0
votes
3answers
781 views
how to send standard output and standard error to two files
I use the following syntax in order to send standard output and standard error to $log file
log=/var/tmp/install.log
info=/tmp/info.log
exec > $log 2>&1
how to redirect both standard ...
0
votes
1answer
1k views
How to make sed regex syntax work as python or javascript? [duplicate]
I have asked a question insert a string to a list variables in text file [use sed]
In which @RomanPerekhrest showed me a different regex syntax.
\(=([^)]*\)) can capture [^)]* as group 1 . This is ...
2
votes
1answer
145 views
Can $PAGER contain spaces?
I'm writing an application from which I want to run a user-specified pager. The standard way to do this seems to be to look at the PAGER environment variable.
I'm unclear as to whether this is a ...
0
votes
2answers
199 views
Sendmail compatibility interface
Postfix (and lots of other stuff) claim they offer sendmail compatible interface. Since I want to write my own sendmail implementation, I was wondering what that actually means. Is there anything RFC-...
2
votes
3answers
6k views
Unprintable characters as input in command line
I've got a program that requires some unprintable characters like 0x0F (ctrl+o) as input to execute the intended part of the program.
0 000 00 NUL � Null ...
11
votes
1answer
504 views
Confusion about changing meaning of arguments and options, is there an official standard definition?
I came across a confusing variation in the understanding what options and arguments are with regard to the syntax of commands.
For instance, I encountered definitions like:
command -a -b -c d e f
...
6
votes
1answer
1k views
Does the UNIX standard require case-sensitive filesystems?
One answer to this question mentions the UNIX 03 certification of OSX. Now AFAIK the standard file system of OSX is/was HFS, which "saves the case of a file that is created or renamed but is case-...
1
vote
1answer
93 views
Any reason why find does not merge multiple slashes into one?
Is it true that find is not supposed to be doing even the most simple path unification/simplifications operations, such as coalescing multiple successive slashes together (which would be equivalent to ...
83
votes
5answers
6k views
Do progress reports/logging information belong on stderr or stdout?
Is there an official POSIX, GNU, or other guideline on where progress reports and logging information (things like "Doing foo; foo done") should be printed? Personally, I tend to write them to stderr ...
3
votes
1answer
11k views
Recommended GID for users group in Linux (100 or 1000)?
I have several GNU/Linux installations that share home and data directories. Over time some user files in these directories have received the group ID 100 (users group under some variants of Linux), ...
0
votes
2answers
51 views
Heuristics for making use of or dismissing old documentation [closed]
Getting them as search results or following reference links, I often come across documentation produced some time ago. A few months, a few years. Sometimes the documents are marked as deprecated or ...
14
votes
2answers
3k views
An official standard / convention for a file extension for shell scripts to source
I was wondering if there is a convention for file type extensions for shell scripts you want to source instead of run. For example:
If I want to run this script in a subshell.
./script.sh
If I ...
1
vote
1answer
55 views
Where can I find the most recent dictionary of standard Linux Audit event fields?
I am writing a converter which takes Linux Audit logs as input. I tried to find the most recent dictionary file where all the valid names of the fields are defined.
I've found such a file[1] but the ...
9
votes
2answers
3k views
Is there a Linux distro that's UNIX certified?
Is there a Linux distribution certified with the Single UNIX Specification? What are the primary reasons that most distributions don't get certified?
4
votes
2answers
4k views
bash: --argument vs -arg [duplicate]
In most scripts (but mainly bash) it's commonplace to see some arguments that are configured like so:
bash-4.3:$ command --longer-argument -la
Where did this originate from? I'm mainly just curious ...
3
votes
2answers
3k views
What is the unix mailbox format?
man git-format-patch makes reference of the UNIX mailbox format which is a term I am unfamiliar with.
A google search for "UNIX mailbox format" and similar expressions lists many hits with the term ...
1
vote
2answers
1k views
Connect to a wireless network as standard user without administrator authentication Linux Mint 17.3
I'm trying to get a standard user on my laptop installed with Linux Mint 17.3 on the wireless. I can get to the internet just fine logged in with an administrator but as soon as i log in with a ...
1
vote
0answers
163 views
How is an icon theme supposed to be organised?
While trying to find out the icon used for a mimetype, I noticed that gnome and oxygen icon themes on my Arch Linux and Ubuntu 14.04 had the following folder structures:
gnome/48x48:
apps mimetypes
...
2
votes
1answer
133 views
Why doesn't cc (the C compiler) and similar utilities use standard streams by default? [closed]
Background
If think most of us agree that filters and pipes are the very foundation of Unix systems.
Pipes and filters are very powerful tools. Almost all Unix utilities use the standard input and ...
2
votes
2answers
4k views
What is the difference between bash script and shell script [duplicate]
As there are different kinds of shells, What is the difference between bash and shell scripts and is there any compatible script on can write that runs on al unix shells
1
vote
1answer
198 views
`man` pages for languages other than C (e.g, python, R, javascript, etc)?
man pages are a phenomenal resource while programming in C on Linux. While looking at someone else's code, if you see something foreign you can immediate research it in another terminal with
$ man 3 ...
1
vote
2answers
280 views
Are basic system administrator utilities such as useradd or adduser standardized?
Are basic system administrator utilities such as useradd or adduser standardized? If so, where can I find the specs? (POSIX doesn't seem to encompass those, but I might need to take a better look).
2
votes
1answer
932 views
Is CTRL+4 equal to ^4 or ^$ in caret notation?
This is a problem I have been thinking about.
This Wikipedia page suggests that Ctrl+{Symbol}
uses the shifted variant of {Symbol} when written in Caret notation.
This suggests that CTRL+\ becomes ^...
3
votes
1answer
1k views
Is there a common naming convention for daemon user accounts?
I'm from a windows background where I'm used to creating separate domain service accounts for running various services. I like to keep things need so I would name them
DOMAIN\service.whatever
I'm ...
7
votes
1answer
314 views
What are the 'n', 'l', '3pm' sections of the manual for?
An excerpt from the man man page:
The default action is to search in all of the available sections following a pre-defined order ("1 n l 8 3 2 3posix 3pm 3perl 5 4 9 6 7" by default)
What are ...
7
votes
1answer
1k views
What three files are always opened by a process?
Someone mentioned that there are three different files that a process always opens. What does this mean? What files are they?
2
votes
1answer
553 views
Propose additional file descriptor “stdmeta” [closed]
I know that one can define additional file descriptors for ad-hoc use. However, I see real use for a "stdmeta" file descriptor that would be supported by common CLI tools. This file descriptor would ...
20
votes
2answers
22k views
practical usage of /etc/networks file
What is the practical usage of /etc/networks file? As I understand, one can give names to networks in this file. For example:
root@fw-test:~# cat /etc/networks
default 0.0.0.0
loopback ...
1
vote
0answers
99 views
OS X Yosemite is SUS - Single Unix Specification 3 certified. But what posix standard is it compliant to? the latest one is 2008
I'm confused. Is SUS compliance the same as POSIX compliance? Is yosemite compliant to the latest standards, what years exactly?
3
votes
1answer
81 views
Are there any user guaranteed to exist on the system
Beside the root (which I guess IS guaranteed), is there any other username guaranteed to exist on Unix system? Linux system? Fixed UIDs for those users? If not guaraneed, are there at least any ...
4
votes
1answer
871 views
Single or double brackets and portability
I have found some very good answers here on the differences between [ and [[ in 'if' statements. For specific named shells, it seems to be a good idea to use [[ over [ (and it is faster, too).
I'm ...
6
votes
2answers
2k views
Is Android compatible with the Linux Standard Base?
Moved from Stack Overflow, where I realize it was off-topic since it was asking for sources - far as I can tell, the rules forbid that there but not here.
I know that the kernel in Android is now ...
4
votes
3answers
661 views
Standard and portable way to send email from console?
What is the most portable or standard way to send an email from the console or a script on Linux, and possibly Unix?
6
votes
3answers
654 views
Are there “esoteric” (weird) but standards-compliant C compilers or runtimes?
As we know, the C standard does not specify a lot of details of the implementation, for example value of NULL pointer, order of bits and bytes (endiannes), alignment in structs and of stack parameters,...
