The operating system is:
SunOS grcs 5.8 Generic_108528-13 sun4u sparc SUNW,Ultra-5_10

This is the script that starts the program:
#!/usr/bin/ksh
export LD_LIBRARY_PATH=/usr/local/lib
export DLI_LOG_MSGS=DEBUG
export DLI_LOG_FILE_NAME=DLIMain.log
./Reader

I've tried calling the script:
rt = execl("./setenv1", "setenv1", (char *) NULL);
if (rt != 0)
printf("exec failure: %d\n", errno);

and I've tried calling the program directly:
rt = execl("./Reader", "Reader", (char *) NULL);
if (rt != 0)
printf("exec failure: %d\n", errno);

Neither works. The Reader is using a UDP socket to read the audio files from the sender. I don't know if that if affecting anything.

I don't know how to use & when calling exec() in C++ code.

Thanks for your help.