file access

[Basti]

Hello,

currently i'm writing a programm for a multi-user system. My problem
is, that i don't know what happens if two or more users use the file
for writing at the same time. Is the file locked if a user does a
write access or do I have to lock the file manually. I'm using fopen
to open a file and fputs to write to te file. Thanks for the
suggestions.

Greets

 

[Christopher Benson-Manica]

currently i'm writing a programm for a multi-user system. My problem
is, that i don't know what happens if two or more users use the file
for writing at the same time. Is the file locked if a user does a
write access or do I have to lock the file manually. I'm using fopen
to open a file and fputs to write to te file. Thanks for the
suggestions.

(It all depends on what OS the system runs, how the users open the
file, and possibly many other variables. It may well be locked, but
it's probably unwise take that on faith.)

Your post is off-topic for comp.lang.c. Please visit

http://www.ungerhu.com/jxh/clc.welcome.txt
http://www.eskimo.com/~scs/C-faq/top.html
http://benpfaff.org/writings/clc/off-topic.html

for posting guidelines and frequently asked questions. Thank you.

 

[Darrell Grainger]

Hello,

currently i'm writing a programm for a multi-user system. My problem
is, that i don't know what happens if two or more users use the file
for writing at the same time. Is the file locked if a user does a
write access or do I have to lock the file manually. I'm using fopen
to open a file and fputs to write to te file. Thanks for the
suggestions.

This is an OS question. Nothing in the C standard defines this. So, you'll
have to ask a newsgroup that knows your OS. It might even be configurable
by the admin.