12-29-2008
As has been explained to you, Linux (the Kernel) and many of the accompanying software is open source.
This means that you are free to edit the files as you wish without fear of reprisals in the form of copyright violations and such for the changes. Other software vendors do not allow you to make these changes to their code as they are proprietary.
Linux does not have "System Files" in so much as what you seem to be describing.
You cannot simply go in and muck about.
You CAN however change parameters of running machines, and do a lot more. What do you wish to change and what are you trying to learn from this?
read up on sysctl and how it can change parameters of the kernel on a running machine. However, be aware that changes you make can disrupt running processes as well as the stability of the machine.
As for editing files in linux, also look up "vi" or "vim" and use that to edit the files themselves, as they are text based editors found on nearly every UNIX or UNIX-Like operating system.
9 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi
I need to access files from a specific folder of a Linux system from an another Linux System Remotely.
I know how to, Export a folder on One SCO System & can access the same by using Import via., NFS in the Sco Unix SVR4 System using the scoadmin utility.
Also, I know to use mount -t ... (2 Replies)
Discussion started by: S.Vishwanath
2 Replies
2. UNIX for Dummies Questions & Answers
Here's what I have...
$ vi foo1
- open foo1 and work around for a while. I yank a few lines into a buffer and then :w to save.
Next I :e foo2 to open foo2 and paste my buffer. I :w to save, but I would like to then be able to go directly back into foo1 where I was before I opened foo2. ... (4 Replies)
Discussion started by: djschmitt
4 Replies
3. Windows & DOS: Issues & Discussions
:D mount -t vfat /dev/hda1 /mnt
my dillemma is simple i have psion 5 mx wich is an epoc type machine not only does it only work on windows as far as I know but I have to convert the files (the usual stuff!) sometimes a humen error happens and the files that I want to transfer to the linux drive... (7 Replies)
Discussion started by: moxxx68
7 Replies
4. UNIX for Dummies Questions & Answers
Hi, I am trying to edit sshd_config file through the vi editor.
logged on as a root.
when I try to write the file I get:
Read-only file, not written; use ! to override
when i type :w!, I get:
Error: etc/ssh/sshd_config Permission denied.
I want to change:
#PermitRootLogin no to yes
freeBDS... (6 Replies)
Discussion started by: emosms
6 Replies
5. UNIX for Dummies Questions & Answers
i need to know how files can be transfered from one system to another securely in linux. (9 Replies)
Discussion started by: bibing
9 Replies
6. Shell Programming and Scripting
Hi,
I want to connect to sqlplus through unix. I got the command to do it. But I was getting error:
./executeSQL.ksh: sqlplus: not found
Then when I googled I found that we have to include Oracle Client path in .profile file. I don't know how to do it. Also I don't have permissions to... (2 Replies)
Discussion started by: dips_ag
2 Replies
7. UNIX for Dummies Questions & Answers
Hi, sometimes one wants to edit files while still seeing output of earlier commands in terminal. I've found out that cat test && cat - >> test does the trick for displaying file content and adding lines but I believe I saw a much cooler command that was also able to erase lines from files. I cannot... (6 Replies)
Discussion started by: scarleo
6 Replies
8. AIX
I have a following requirement in production
system 1 : LINUX
User: abcd
system 2: AIX (it is hosting a production DB)
Requirement
user abcd from system 1 should have read access on archive log files created by DB on system 2. The log files are created with permissions 540 by user ora ,... (2 Replies)
Discussion started by: amitnm1106
2 Replies
9. Shell Programming and Scripting
Experts - I have an requirement to gunzip and edit many files in a pair of directories.
I have two scripts that work great when run separately, but I'm having problems
combining the two.
The goal is to gunzip the files found in the first script and pipe them to the
bash/sed script and... (9 Replies)
Discussion started by: timj123
9 Replies
LEARN ABOUT CENTOS
sysctl
SYSCTL(2) Linux Programmer's Manual SYSCTL(2)
NAME
sysctl - read/write system parameters
SYNOPSIS
#include <unistd.h>
#include <linux/sysctl.h>
int _sysctl(struct __sysctl_args *args);
Note: There is no glibc wrapper for this system call; see NOTES.
DESCRIPTION
Do not use this system call! See NOTES.
The _sysctl() call reads and/or writes kernel parameters. For example, the hostname, or the maximum number of open files. The argument
has the form
struct __sysctl_args {
int *name; /* integer vector describing variable */
int nlen; /* length of this vector */
void *oldval; /* 0 or address where to store old value */
size_t *oldlenp; /* available room for old value,
overwritten by actual size of old value */
void *newval; /* 0 or address of new value */
size_t newlen; /* size of new value */
};
This call does a search in a tree structure, possibly resembling a directory tree under /proc/sys, and if the requested item is found calls
some appropriate routine to read or modify the value.
RETURN VALUE
Upon successful completion, _sysctl() returns 0. Otherwise, a value of -1 is returned and errno is set to indicate the error.
ERRORS
EFAULT The invocation asked for the previous value by setting oldval non-NULL, but allowed zero room in oldlenp.
ENOTDIR
name was not found.
EACCES, EPERM
No search permission for one of the encountered "directories", or no read permission where oldval was nonzero, or no write permis-
sion where newval was nonzero.
CONFORMING TO
This call is Linux-specific, and should not be used in programs intended to be portable. A sysctl() call has been present in Linux since
version 1.3.57. It originated in 4.4BSD. Only Linux has the /proc/sys mirror, and the object naming schemes differ between Linux and
4.4BSD, but the declaration of the sysctl() function is the same in both.
NOTES
Glibc does not provide a wrapper for this system call; call it using syscall(2). Or rather... don't call it: use of this system call has
long been discouraged, and it is so unloved that it is likely to disappear in a future kernel version. Since Linux 2.6.24, uses of this
system call result in warnings in the kernel log. Remove it from your programs now; use the /proc/sys interface instead.
This system call is available only if the kernel was configured with the CONFIG_SYSCTL_SYSCALL option.
BUGS
The object names vary between kernel versions, making this system call worthless for applications.
Not all available objects are properly documented.
It is not yet possible to change operating system by writing to /proc/sys/kernel/ostype.
EXAMPLE
#define _GNU_SOURCE
#include <unistd.h>
#include <sys/syscall.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/sysctl.h>
int _sysctl(struct __sysctl_args *args );
#define OSNAMESZ 100
int
main(void)
{
struct __sysctl_args args;
char osname[OSNAMESZ];
size_t osnamelth;
int name[] = { CTL_KERN, KERN_OSTYPE };
memset(&args, 0, sizeof(struct __sysctl_args));
args.name = name;
args.nlen = sizeof(name)/sizeof(name[0]);
args.oldval = osname;
args.oldlenp = &osnamelth;
osnamelth = sizeof(osname);
if (syscall(SYS__sysctl, &args) == -1) {
perror("_sysctl");
exit(EXIT_FAILURE);
}
printf("This machine is running %*s
", osnamelth, osname);
exit(EXIT_SUCCESS);
}
SEE ALSO
proc(5)
COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2012-12-22 SYSCTL(2)