I 'm using CYGWIN (the last version 1.5.19.4). My application use the
IPC messages queue.
The cygserver is started correctly.
The application server side (is a service) is launched by cygrunsrv ...
with -e CYGWIN=server , it is OK
If I launch the application client in a shell script, it is OK if I set
before launching the application, the CYGWIN variable to server. It's
normal.
My problem is :
----------------------
- The application client is a CGI written in C, launched by Apache or
IIS , and I don't know how to set the CYGWIN variable before the
application is launched.If I use Apache I can use the SetEnv directive
to set a variable in the Apache configuration file. But with IIS I
don't know to do that. I need a global solution for Apache and IIS.
So , I tried to set the environment variable CYGWIN to server with the
routines setenv(), putenv(), SetEnvironmentVariable() inside the CGI
code. I have always the "Bad system call " error when the program
executes msgget. It seems that the setenv function doesn't run while the
getenv function returns the right value !!
I wrote a test program to reproduce the problem:
- rcv_msg.c waits for messages
- send_msg.c sends messages
The test programs are launched in a shell window.
_Test NOK
_The variable CYGWIN is set in the shell for the server rcv_msg .
The variable CYGWIN is set inside the send_msg.c program (setenv routine)
The file /tmp/xx must exist. The programs are launched in 2 different
shell windows
/$/ */export CYGWIN=server/*
/$ ./rcv_msg.exe /tmp/xx
Call ftok /tmp/xx
command_file=/tmp/xx,key=16068417
Call msgget
Return msgget 3538944
Loop msgrcv
$ *unset CYGWIN*
$ ./send_msg.exe /tmp/xx AAA
Call getenv CYGWIN
Value returned by getenv CYGWIN =(null)
Call setenv CYGWIN=server
Value returned by setenv CYGWIN result=0
Call getenv CYGWIN
Value returned by getenv CYGWIN =server
Call msgget
Bad system call
/_Test OK (CYGWIN variable set in the shell for the server and client
application ): _
/$/ */export CYGWIN=server/*
/$ ./rcv_msg.exe /tmp/xx
Call ftok /tmp/xx
command_file=/tmp/xx,key=16068417
Call msgget
Return msgget 3538944
Loop msgrcv
Message=AAA
//$/* /export CYGWIN=server/*
/$ ./send_msg.exe /tmp/xx AAA
Call getenv CYGWIN
Value returned by getenv CYGWIN =(null)
Call setenv CYGWIN=server
Value returned by setenv CYGWIN result=0
Call getenv CYGWIN
Value returned by getenv CYGWIN =server
Call msgget/
_Note:_ I used ipc-daemon in my previous version, and it was OK. There was no
environment variable to set.
Thanks to help me.
Martine
--
Martine Carannante
System Software Development R&D
Bull, Architect of an Open World TM
Tél : (+33) 1 30 80 71 87
http://www.bull.com
#include <stdio.h>
#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/ipc.h>
#include <sys/msg.h>
int message_queue_id;
#define MAX_INPUT_BUFFER 1024
int main(int argc, char **argv){
char buffer[1024];
char command_file[1024];
int result;
struct My_msgbuf {
long mtype;
char mtext[1024];
}rbuf ;
/*struct msgbuf rbuf;*/
if (argc < 2)
{
printf("Key (existing)file argument missing\n");
printf("Usage: rcv_msg <file for the key>\n");
exit(-1);
}
strcpy(command_file,argv[1]);
result=open_command_file(command_file);
if (result != 0) exit(-1);
printf("Loop msgrcv\n");
while (result=msgrcv(message_queue_id,&rbuf,MAX_INPUT_BUFFER,0,0) != -1)
{
printf("Message=%s\n",rbuf.mtext);
}
}
int open_command_file(char * command_file)
{
key_t key;
int result;
result=open(command_file,O_CREAT|O_RDWR,S_IWUSR);
printf("Call ftok %s\n",command_file);
key=ftok(command_file,'A');
printf("command_file=%s,key=%d\n",command_file,key);
if (key == -1){
perror("Ftok\n");
return -1;
}
printf("Call msgget \n");
message_queue_id = msgget(key,(IPC_CREAT|IPC_EXCL|0666));
printf("Return msgget %d \n",message_queue_id);
if (message_queue_id == -1){
perror("msgget\n");
return -1;
}
return 0;
}
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#define MAX_FILENAME_LENGTH 1024
#define MAX_INPUT_BUFFER 1024
#define OK 0
extern char ** environ;
#define ERROR -1
char command_file[MAX_FILENAME_LENGTH];
char command_line[MAX_INPUT_BUFFER];
/* write a command entry to the command file */
int main(int argc, char **argv){
FILE *fp;
int message_queue_id;
key_t key;
/*struct msgbuf sbuf;*/
struct msgbuf {
long mtype;
char mtext[1024];
}sbuf;
int result;
char *value;
if (argc < 3)
{
printf("Argument missing");
printf("Usage : send_msg <Key existing file> <message>\n");
exit(ERROR);
}
/* get the command line argument*/
strcpy(command_file,argv[1]);
strcpy(command_line,argv[2]);
key=ftok(command_file,'A');
printf("Call getenv CYGWIN\n");
value=getenv("CYGWIN");
printf("Value returned by getenv CYGWIN =%s\n",value);
printf("Call setenv CYGWIN=server\n");
result=setenv("CYGWIN","server",1);
printf("Value returned by setenv CYGWIN result=%d\n",result);
printf("Call getenv CYGWIN\n");
value=getenv("CYGWIN");
printf("Value returned by getenv CYGWIN =%s\n",value);
/*SetEnvironmentVariable("CYGWIN","server");*/
/* open the command for writing (since this is a pipe, it will really
be appended) */
printf("Call msgget\n");
message_queue_id = msgget(key,0666);
if (message_queue_id == -1)
{
perror("Error: msgget 0666 !\n");
printf("command_file =%s key=%d\n",command_file,key);
return ERROR;
}
sbuf.mtype=1;
strcpy(sbuf.mtext,command_line);
if(msgsnd(message_queue_id,&sbuf,strlen(sbuf.mtext)+1,IPC_NOWAIT) <0){
perror("Error: msgsnd!\n");
return ERROR;
}
return OK;
}
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