10-14-2004
Interprocess communication using pipes and fork
I'm very worried. I have an assignment that is due in 3 weeks, and also tute exercises which I can't seem to understand and work out.
Okay, the question:
The parent process will convert the command arguments into integer values using atoi() and store them into an integer array which you will create using malloc() ONLY and is to be a local variable declared in main(). The parent process will then send the values of the array to Process B by writing to pipe1's output stream.
My question here is when i pass it through the pipe to Process B the output is always incorrect, gives me some rubbish. The examples which I've found also always pass string thru the pipe. Can I pass the pointer of the array to Process B and ask Process B to read the input from there?
I don't know why I find this so difficult to understand and have been looking around the internet for notes or examples to ponder on, but seems like all the examples are passing strings thru pipes.
Really really appreciate any sort of help here.
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LEARN ABOUT OPENSOLARIS
wscol
wstring(3C) Standard C Library Functions wstring(3C)
NAME
wstring, wscasecmp, wsncasecmp, wsdup, wscol - Process Code string operations
SYNOPSIS
#include <widec.h>
int wscasecmp(const wchar_t *s1, const wchar_t *s2);
int wsncasecmp(const wchar_t *s1, const wchar_t *s2, int n);
wchar_t *wsdup(const wchar_t *s);
int wscol(const wchar_t *s);
DESCRIPTION
These functions operate on Process Code strings terminated by wchar_t null characters. During appending or copying, these routines do not
check for an overflow condition of the receiving string. In the following, s, s1, and s2 point to Process Code strings terminated by a
wchar_t null.
wscasecmp(), wsncasecmp()
The wscasecmp() function compares its arguments, ignoring case, and returns an integer greater than, equal to, or less than 0, depending
upon whether s1 is lexicographically greater than, equal to, or less than s2. It makes the same comparison but compares at most n Process
Code characters. The four Extended Unix Code (EUC) codesets are ordered from lowest to highest as 0, 2, 3, 1 when characters from different
codesets are compared.
wsdup()
The wsdup() function returns a pointer to a new Process Code string, which is a duplicate of the string pointed to by s. The space for the
new string is obtained using malloc(3C). If the new string cannot be created, a null pointer is returned.
wscol()
The wscol() function returns the screen display width (in columns) of the Process Code string s.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------------------------------------+
|ATTRIBUTE TYPE ATTRIBUTE VALUE |
|MT-Level MT-Safe |
+-----------------------------------------------------------+
SEE ALSO
malloc(3C), string(3C), wcstring(3C), attributes(5)
SunOS 5.11 29 Dec 1996 wstring(3C)