That's not the preferred way to specify file modes in UNIX. By not giving it the O_CREAT file it means that the file exists and the open call will have no affect on it and instead of giving 0644 for the file mode bits use...
That's for creating and opening a file that does not exist because if it does then the open call fails so should check its return value.
What does the system call "dup" do?
What is the difference between dup and dup2
I have a fair idea of what it does but I am confused when its coming down to the exact details...
Please help me!:confused: (2 Replies)
open, creat, read, write, lseek and close
Are they all primitive?
:confused:
*Another Question: is there a different between a system call, and an i/o system call? (2 Replies)
Hi,
I'm new to UNIX system calls. Can someone share your knowledge as to how exactly system calls should be executed?
Can they be typed like commands such as mkdir on the terminal itself? Also, are there any websites which will show me an example of the output to expect when a system call like... (1 Reply)
Hello,
how would i be able to call ps in C programming?
thanks,
---------- Post updated at 01:39 AM ---------- Previous update was at 01:31 AM ----------
here's the complete system call, ps -o pid -p %d, getpit() (2 Replies)
I'm currently studying for my exam, and is practicing with sample exam questions.
However there is a question asking "Name THREE UNIX Directory system calls" and the answer given is "opendir, closedir and readdir", however the next question ask "Why is a write directory system call not included... (1 Reply)
Hello...
I'm trying to setup a cronjob to record system data using glance at certain times of the day. My question is, how would one export the "Global System Calls" information to a file? Below is the command I have been using and it works to export CPU information.
glance -f ... (0 Replies)
Hi i am very new to programming in UNIX and don't understand the difference between a system call and a normal function call. Also can I implement system calls from within a program? If so could someone please give me an example of a system call from within a program. Lastly, when creating a... (1 Reply)
Discussion started by: bjhum33
1 Replies
LEARN ABOUT SUNOS
creat
creat(2) System Calls creat(2)NAME
creat - create a new file or rewrite an existing one
SYNOPSIS
#include <sys/stat.h>
#include <fcntl.h>
int creat(const char *path, mode_t mode);
DESCRIPTION
The function call
creat(path, mode)
is equivalent to:
open(path, O_WRONLY | O_CREAT | O_TRUNC, mode)
RETURN VALUES
Refer to open(2).
ERRORS
Refer to open(2).
EXAMPLES
Example 1: Creating a File
The following example creates the file /tmp/file with read and write permissions for the file owner and read permission for group and oth-
ers. The resulting file descriptor is assigned to the fd variable.
#include <fcntl.h>
...
int fd;
mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
char *filename = "/tmp/file";
...
fd = creat(filename, mode);
...
USAGE
The creat() function has a transitional interface for 64-bit file offsets. See lf64(5).
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
|MT-Level |Async-Signal-Safe |
+-----------------------------+-----------------------------+
SEE ALSO open(2), attributes(5), largefile(5), lf64(5), standards(5)SunOS 5.10 25 Mar 2002 creat(2)