16,884 reputation
22156
bio website stratigery.com
location Denver, CO
age 53
visits member for 4 years
seen 1 hour ago

My first computer was a Radio Shack Color Computer 3 - 6809-based, running OS-9 Level II. It could run 32 processes at once, due to bank-switching a whole 1 Meg of memory.

After that, I got an AT&T 3b2, also known as a Convergent Safari. This was a Motorola 68010-based desktop.

Then, I graduated to a NeXT black&white "slab". I bought a used SPARCStation IPC in 1995, and put NetBSD 0.9 on it. I ran NetBSD on the IPC and a SPARCStation 10 until 2002.

I've been using Linux since 1997, starting with a DEC Alpha-based UDB, and downgrading to a x86 PC in 2002.

I run Arch linux, on my server and my laptop.


Aug
15
comment Malloc and Paging
@user100503 - Yes, malloc()/calloc()/realloc() allocate from the heap. A little-used function alloca() allocates on the stack, but it's easy to make mistakes with alloca(). I believe that writing to an allocated page causes the kernel to actually allocate the physical memory. I can't point at any code or anything, but I'm still pretty sure.
Jul
31
comment How do pwd and . determine the current path differently?
In Unix, Linux and other filesystems, an inode number is actually a file's identifier to the operating system. Depends on the filesystem, but there's usually a very quick way to go from inode number to the disk block that the inode lives. The inode itself is the on-disk structure representing a file: ownership, permissions, which data blocks contain file's data, access times, etc. A directory is just a mapping from a textual name to an inode number, the quick lookup of disk block from inode number allows the OS to get data and metadata quickly.
Jul
29
comment What is #@(#) in Kornshell syntax
@MaxVernon - you're welcome. I personally love this kind of question, as it exposes actual practices to a wider community, and it lets me mine my memory for whatever absurditites it has retained. If I might editorialize: "@(#)" saved me a few times in High Ritual production environments in the past. Why hasn't it survived? Knowing what versions got compiled together seems like valuable info.
Jul
28
comment Difference between Unix OS Types
OSX is derived from Mach 2.5, with a thin layer of BSD compatibility on top. I'm not so sure it's FreeBSD, it might actually be BSD 4.4 lite or whatever that last BSD release was.
Jul
28
comment Linux kernel manual build: resulting binary is 10 times larger than precompiled binaries
I don't know about modules. That was one question I had before I recommeded make vmlinuz.
Jul
21
comment Updating PHP to Gaurd Against Mayhem Malware
@Boundless - the code I got, which is identical to what Virus Bulletin reports (virusbtn.com/virusbulletin/archive/2014/07/vb201407-Mayhem) only uses simple PHP - fopen()/fclose() is about as exotic as it gets. The dropper code does call system(), which runs a command via the shell, so you could potentially disable system(): cyberciti.biz/faq/… Like I wrote above, the PHP it uses is nothing special.
Jul
18
comment Low level system call
@saurav1405 - you can look at the source to find out, but for Musl libc, you can look at http://git.musl-libc.org/cgit/musl/tree/src/unistd/read.c - it's in C, but it uses a macro that I trace to the file src/thread/x86_64/syscall_cp.s. The macro expands into in-line assembly. So I'm not sure what to call it: "written in assembly" or "written in C with a line or two of assembly". Probably the latter.
Jun
20
comment What's the difference of the Userland vs the Kernel?
@r004 - see edits. I used wireless cards, but driver software makes SATA, SCSI and IDE disks all look the same too, despite vast differences in what they can do.
Jun
18
comment Why does fstab use UUID instead of the actual file system name?
If I answered the original question, it might be a good idea to mark it "answered" and write a new question, just so you don't collect irrelevant answers, answers that work with the original and not the modified question.
May
31
comment What does ${3#?} do?
@mikeserv - your code doesn't look crazy to me. If you need to remove the first character of a variable's value, that's one way of doing it. The "${3#?}" usage seems to hide what it's doing, rather than make it explicit.
May
28
comment What does ${3#?} do?
Why do you write "usually used in functions"? I'm at a loss to understand why you'd want to drop the first character of an argument.
May
20
comment Is TWM still a viable window manager?
I use twm as a matter of choice. Every once in a while, something will act strangely, but that's very rare. Typically only commercial software will have any trouble.
May
17
comment Why doesn't 'ar' work like the manpage says?
Under Arch Linux, /usr/bin/ar and /usr/bin/ranlib have different inode numbers, and hence, are different files. However, @MarkPlotnick is correct: the usage message you get is from ranlib, somehow. Do ls -li /usr/bin/ranlib /usr/bin/ar to see if the inode numbers differ. On my x86_64 machine, inodes differ, but file sizes are identical. cksum does show differeent checksums, so they're two different filees.
May
10
comment Wifi card not detected - Archlinux
Is this a built-in or an external WiFi card? Got any hints about brand, chipset,etc?
May
10
comment Apache2 won't start in Arch Linux
Even if your system uses systemd, you can still do a apachectl configtest to debug configuration problems.
May
2
comment iw not detecting my usb Wifi card
If it's a USB WiFi adapter, run lsusb and try to identify which device it is. Include lsusb output in your question so all can see. Sometimes a vendor changes the USB ID of some gizmo to a value that the Linux driver doesn't recognize.
Apr
15
comment Are system calls the only way to interact with the Linux kernel from user land?
That seems almost vacuous. If we count hardware traps into the kernel, then a busy loop which just eats an entire time-slice counts as "interacting" with the kernel, doesn't it?
Apr
12
comment Change Apache httpd “Server:” HTTP header
This does work, thank you very much. I have to note that mod_security is not one of Arch Linux's ordinary packages. There's a PKGBUILD in the AUR, but it hasn't been updated since 2011 (as of April 12, 2014) and it references a really old version of mod_security. As always, your distro may vary.
Apr
10
comment Change Apache httpd “Server:” HTTP header
@MichaelOzeryansky - thanks for catching the misspelling. It is "httpd.conf" I do stop and start httpd after changing httpd.conf.
Apr
5
comment Are there any alternatives to mutt?
I'd like to echo Faheem Mitha's personal Pine story. Oddly, I switched from BSD mail to Pine around 1994. I've tried Mutt, too, but never made the switch.