it doesnt work properly. do you know what is the problem?
Like they said, it's not a shell, it doesn't split for you.
Also, if it did work, your program would immediately quit, because execl doesn't launch a new program -- it replaces your current program. If you want to create a new process, you have to fork first, then exec. Watch the return value of fork carefully. It creates a clone of your process, and its return value is the only thing which tells them which is which. You have to make sure your child process only does what the child should be doing and not anything else, make sure it quits if exec doesn't work and such.
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)
Hi friends,
I have three questions.
1) What are system calls?
2) Is it necessary that system calls be in c language (in unix operating system)?
3) Importance of c language when programming in unix environment???
Looking forward to your wonderful replies!
... (2 Replies)
Hi friends,
I hope everyone is fine and doing well. I queried in my previous thread about the low-level qualities of C/C++ languages.I really thank you people for explaining, it was really helpful. One more ambiquity that I have in my mind is regarding the unix system calls like open, creat,... (1 Reply)
Discussion started by: gabam
1 Replies
LEARN ABOUT DEBIAN
ns_fork
Ns_Exec(3aolserver) AOLserver Library Procedures Ns_Exec(3aolserver)__________________________________________________________________________________________________________________________________________________NAME
Ns_ExecArgblk, Ns_ExecArgv, Ns_ExecProc, Ns_ExecProcess, Ns_Fork, Ns_GetEnviron, Ns_WaitForProcess, Ns_WaitProcess, ns_fork - External
process execution
SYNOPSIS
#include "ns.h"
int
Ns_ExecArgblk(char *exec, char *dir, int fdin, int fdout,
char *args, Ns_Set *env)
int
Ns_ExecArgv(char *exec, char *dir, int fdin, int fdout,
char **argv, Ns_Set *env)
int
Ns_ExecProc(char *exec, char **argv)
int
Ns_ExecProcess(char *exec, char *dir, int fdin, int fdout,
char *args, Ns_Set *env)
int
Ns_Fork(void)
char
**Ns_GetEnviron(void)
int
Ns_WaitForProcess(int pid, int *statusPtr)
int
Ns_WaitProcess(int pid)
int
ns_fork(void)
_________________________________________________________________DESCRIPTION
These functions handle fork and exec operations. See files: nsd/exec.c, nsd/tclenv.c and nsthread/fork.c.
Ns_ExecArgblk(exec, dir, fdin, fdout, args, env)
Executes a command in a child process. Return process id of child process exec'ing the command or -1 on failure. Provides extended
error checking and error messages.
Ns_ExecArgv(exec, dir, fdin, fdout, argv, env)
Execute a command in a child process using fork(2) and execve(2), returns the process id of child process exec'ing the command or -1
on failure. The child sends an extended error message to the parent.
Ns_ExecProc(exec, argv)
Executes a command in a child process. Returns the process id of the child process exec'ing the command or -1 on failure. Simpli-
fies call to Ns_ExecArgv.
Ns_ExecProcess(exec, dir, fdin, fdout, args, env)
Executes a command in a child process. Returns the process id of the child process exec'ing the command or -1 on failure. Calls
Ns_ExecArgblk with same arguments.
Ns_Fork()
Posix style fork(), using fork1() on Solaris if needed. See fork(2) man page. Calls ns_fork.
Ns_GetEnviron()
Returns pointer to the environment vector.
Ns_WaitForProcess(pid, statusPtr)
Wait for child process. Returns NS_OK on success, or NS_ERROR on failure. *statusPtr is set to the exit code of the child process.
Ns_WaitProcess(pid)
Wait for child process. Calls Ns_WaitForProcess with NULL statusPtr. Returns NS_OK on success, or NS_ERROR on failure.
ns_fork()
Posix style fork(), using fork1() on Solaris if needed.
SEE ALSO nsd(1), info(n)
KEYWORDS AOLserver 4.0 Ns_Exec(3aolserver)