The history of Unix systems and their main components. Please DO NOT USE this tag for shell-related questions; use "command-history" instead.

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Is there any history to the shell prompt? [duplicate]

Traditionally, users get the $ prompt and root gets the # prompt but is there any history why this is so?
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2answers
80 views

Why is $ the default symbol for a user shell and # the default symbol for a root shell?

Operating a standard bash shell on a server, the PS1 prompt defaults to ending in a $ for non-root users, and # for root. IE: ubuntu@server:~$ sudo su root@server:/home/ubuntu# Why is this?
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2answers
33 views

Autocomplete hostnames when using SSH within history file

I'm looking for a feature that help me to autocomplete the servers I "sshed" in sometime and are in my .bash_history file without messing with known_hosts file or /etc/bash_completition, just grab ...
4
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2answers
35 views

How would I get my terminal to regurgitate the previous output text from past commands? Is this even possible?

I just ran a job that takes several hours, and I forgot to pipe that text into a text file. pseudocode: echo [previous text output] > OutputHistory.txt Additionally, I can't just "copy and ...
3
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1answer
57 views

What was the first Unix platform to have the 'yes' command?

I have just answered this question on SO, and it fired off my curiosity a little. So I've searched around but can't find an answer ('yes' is a difficult thing to search for!) There are related ...
71
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5answers
10k views

Why can't Linux usernames begin with numbers?

Is there a technical reason why? Is this an artifact from the early days of Linux or Unix, and if so is there a reason why it persists?
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3answers
26 views

Is it possible to tab through the commandline history for a particular command?

For example, can I see all the previous parameters I passed to the command ssh (i.e. all the server addresses I passed as a parameter when calling ssh)? This is going to be something similar to the '...
1
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1answer
41 views

why isn't there a historical pretty log of your upgrades, downgrades and package purges in Debian?

I wanted to lookup history of my recent updates/upgrades, package purges and found out that other than aptitude and ugly dpkg.log, there doesn't seem to be anything else which does the same. See ...
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0answers
33 views

When was pipelining introduced?

I understand early versions of Unix were licenced from AT&T to Universities and ran on PDP computers. I read in Tanenbaum's book (operating systems) that the first versions of Unix were only a ...
3
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1answer
66 views

When did bash's shopt huponexit start defaulting to off?

On Monday morning, I logged into a box with ssh and ran the following command: tail -f /var/log/foo/bar.log | grep something_interesting & At some point later in the day, I logged out by ...
3
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3answers
136 views

When was the UNIX single-user vs multi-user modes distinction first introduced?

Practically if not actually every single UNIX-like operating system today makes the distinction between multi-user and single-user modes. Single user mode is generally intended for low-level system ...
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2answers
407 views

Why are HTTP operations usually written in all caps? [closed]

I'm looking for the history of this. Why do we usually write HTTP POST or OPTIONS operations in all caps?
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4answers
65 views

Why is it find dir -name file and not find -n dir file?

I've searched around for this but I couldn't find anything on it. I've always wanted to know, why is it that most other built in bash commands have the format of command -flag arg1 arg2, i.e. cp -r ...
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3answers
78 views

Comparing integers: arithmetic expression or conditional expression

In Bash, two integers can be compared using conditional expression arg1 OP arg2 OP is one of ‘-eq’, ‘-ne’, ‘-lt’, ‘-le’, ‘-gt’, or ‘-ge’. These arithmetic binary operators return true if ...
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1answer
88 views

Why does GNU say it is “Not Unix”? [closed]

I use Fedora. Today I found GNU (on the web) about which I didn't know till yesterday. I knew that GNU is a Unix-like operating system that is free software but I didn't get why they say GNU's "Not ...
2
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3answers
755 views

Why can't Korn Shell do ctrl-r?

If I use PC-BSD with the default shell (Korn) then Ctrl+r doesn't work. Why won't it work? Ctrl-r was introduced to search your history in the late 1970s or early 80s and my BSD still can't do it (...
2
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1answer
53 views

Unix vs OS360 (History)

I read the history of Unix operating system and also read the original Unix paper by Thompson and Ritchie. In their paper they mention some key features which Unix uses. Some terminologies including ...
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2answers
155 views

What is the name of an animal used as a logo by the GNU Project? [closed]

What is the name of an animal used as a logo by the GNU Project (gnu.org)? And why was this animal chosen to represent the project?
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1answer
90 views

What is the historical origin of CTRL + P for up and CTRL + N for down?

I am a moderately experienced vim user, who is now beginning to use GNU emacs. At about the same time as I learned that Ctrl-p and Ctrl-n are the default for up and down in emacs, I also learned they ...
1
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1answer
20 views

What was xhbin?

I've googled, searched Unix & Linux Stack Exchange, and... well, there's not really much else I can do, is there? I was browsing some quines in various shell languages, and I came upon the ...
2
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1answer
32 views

Behold System V; what about systems I-IV?

System V (by AT&T) is the ancestral Unix, and I have used it. But I have never read or heard anything about systems I-IV, other than they existed once upon a time in the dim past. How effective ...
1
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2answers
60 views

Why was shar written if tar already existed?

According to the BSD man pages, tar first appeared in Version 7 UNIX in 1979, but shar first appeared in 4.4BSD, which was released in 1994. What were the perceived advantages to shar at the time? ...
2
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0answers
45 views

put string to commandline

I am making a bashfunction that show a menu binded to pgdown to browse through a a window which list my history (like 4dos/4nt etcetera). I have made so one line is always highlighted. $pos is ...
1
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1answer
57 views

'revert' bash to searching correct history file [closed]

I hope this makes sense as I explain it, so please bear with me! I recently decided it would be a good idea to start backing up my history, and did so with the following added to .bashrc: export ...
1
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2answers
81 views

Why doesn't unix filesystem store creation time of a file? [duplicate]

Is there any historic reason? Stat stores last accessed time, last modified time and last changed time , but not the creation time! Isn't that important information. I can't understand why the ...
1
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1answer
57 views

Why is uninterruptible sleep indicated by 'D'?

From "man ps": R = Running or Runnable S = interruptable Sleep T = sTopped Z = Zombie D = uninterruptible sleep (usually IO) Where does this D come from?
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1answer
164 views

Why is the circumflex/caret character used as a symbol for Ctrl?

I started using the Linux console a long time ago but I never questioned myself about the circumflex aka caret character (^). I'd like to ask why it's used as a replacement for the word Ctrl. I ...
2
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1answer
49 views

Why is the xargs -i option deprecated?

I was reading the Linux man page for xargs recently, and it appears that the -i option is deprecated. To quote from the documentation: -i[replace-str], --replace[=replace-str] This ...
27
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4answers
2k views

Does vi silently add a newline (LF) at the end of file?

I have trouble understanding a weird behavior: vi seems to add a newline (ASCII: LF, as it is a Unix (AIX) system) at the end of the file, when I did NOT specifically type it. I edit the file as such ...
0
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3answers
144 views

get IP address who modified a file

I am looking a way to to get the history of a file, like the modification date, who modified this file (ip address or username), the changed lines Is there a way to get the IP address or username of ...
5
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1answer
147 views

Origin of /etc/termcap linux entry

Why is there a type of $TERM called linux described in /etc/termcap? Why and when was it created and what's the point of it? Couldn't we just stay with vt-generic? Is linux just a customary name and a ...
4
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2answers
98 views

Purpose of find command's default size unit 512 bytes

The find command allows you to search by size, which you can specify using units spelled out in the man page: File uses n units of space. The following suffixes can be used: `b' for 512-byte ...
75
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9answers
5k views

On what systems is //foo/bar different from /foo/bar?

Throughout the POSIX specification, there's provision (1, 2, 3...) to allow implementations to treat a path starting with two / specially. A POSIX application (an application written to the POSIX ...
0
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0answers
23 views

Save history to separate file with time-stamp and who did the action

I'm looking for a solution to capture all Linux commands to some file, there are many solutions but I prefer to capture all History to some file. I want it to include : "time-stamp" "Server-name" "...
1
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1answer
111 views

History of UNIX not including current directory in $PATH

In the UNIX world, it's well understood that you need to prefix binaries in the current directory with ./ in order to run them: . is not in $PATH by default. This is to avoid evil binaries overriding ...
0
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4answers
147 views

How to run Unix?

I always wanted to try Unix but I can't seem to find an ISO file or somewhere to buy it. Is Unix published for the whole wide world to use or is it a special OS only for high-class servers, mainframes ...
11
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2answers
731 views

Is there a reason why the first element of a Zsh array is indexed by 1 instead of 0?

From my experience with modern programming and scripting languages, I believe most programmers are generally accustomed to referring to the first element of an array by 0 as index. Are there any ...
48
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6answers
3k views

Is there any reason to have a shebang pointing at /bin/sh rather than /bin/bash?

In most shell scripts I've seen (besides ones I haven't written myself), I noticed that the shebang is set to #!/bin/sh. This doesn't really surprise me on older scripts, but it's there on fairly new ...
0
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1answer
82 views

What can be considered as operating system? [closed]

I am talking about GNU/Linux but not about GNU or Linux! I know that Kernel is the core component in operating system but I want to know what defines the "operating system" (What can be considered as ...
40
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4answers
5k views

Is the shell ksh93 dead?

On 10/1/2013 Glenn Fowler posted this to the ast-users mailing list: As has been pointed out several times on the AST and UWIN lists, AT&T gives very little support to OpenSouce software, ...
0
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1answer
135 views

What really is bash? (or any linux shell) [duplicate]

I understand bash as a window where I can type commands to linux. Reading the wikipedia, I've learned that there were various shell applications throughout the history. First, I understood bash as ...
4
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1answer
78 views

Why does a '.' work in chown?

Why does GNU chown user.group work? The docs say nothing of the syntax being supported. Is there a juicy story behind it?
2
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1answer
74 views

Why do GNU tools use non-matching ` and ' to quote errors?

GNU tools often output error and warning messages with parts of the line (e.g. filenames, syntax errors, invalid dates, etc) quoted with non-matching quotes: ` and ' e.g. From the GNU coreutils FAQ: ...
2
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2answers
104 views

Was 'diff' included in the first version of Linux

What is the list of programs that were available in the first public version of Linux distribution (not just kernel)? I am specially concerned when this distribution was released and if diff utility ...
7
votes
1answer
122 views

Why does 8250 UART driver not wake up TTY if more than 256 characters are pending?

What is the motivation of this if-condition in void serial8250_tx_chars(struct uart_8250_port *up)? if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); It has been ...
1
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1answer
71 views

Relation between emacs and bash terminal shortcuts [closed]

I would like to know what is the relation between emacs and bash terminal shortcuts.
1
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1answer
49 views

Zeller's congruence and cal command

According to Zeller's Congruence, the day of 29 Feb, 1600 is Tuesday. However, the cal command shows it as Friday.Is there a bug in cal's code or a limit on the range of years which Zeller's ...
29
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5answers
2k views

What is the point of mv -f?

The GNU Coreutils manual for mv says: -f --force Do not prompt the user before removing a destination file. However, this already seems to be the default behaviour for mv, so the -f option appears ...
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3answers
1k views

The Linux kernel: breaking user space

I started thinking about this issue in the context of etiquette on the Linux Kernel Mailing list. As the world's best known and arguably most successful and important free software project, the Linux ...
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0answers
39 views

What is the background of the program segmentation?

Each program is separated into several segments like: code segment data segment stack segment heap segment But who was responsible for that progression? The compiler and linker has to support that ...