Shell Programming and Scripting

#include <stdio.h>
#include <unistd.h>

int main()
{
    int i;

    for(i=0; i<3; i++)
    {
        fprintf(stdout, "This is message n. %d on the standard output\n", i);
        fprintf(stderr, "This is message n. %d on the standard error\n", i);
        sleep(1);
    }

    return 0;
}

#!/bin/bash

COMMAND="stdoutAndstderr"
OUTLOG="stdout.log"
ERRLOG="stderr.log"

log()
{
    while read LINE; do
        echo "$(date +"%D %T") - ${LINE}" >> ${ERRLOG}
    done
}

$(pwd)/${COMMAND} 2>&1 >> ${OUTLOG} | log

echo "${OUTLOG}:"
cat ${OUTLOG}
echo ""
echo "${ERRLOG}:"
cat ${ERRLOG}

exit 0

 $ ./stdoutAndstderr.sh
stdout.log:
This is message n. 0 on the standard output
This is message n. 1 on the standard output
This is message n. 2 on the standard output

stderr.log:
05/20/10 15:18:52 - This is message n. 0 on the standard error
05/20/10 15:18:53 - This is message n. 1 on the standard error
05/20/10 15:18:54 - This is message n. 2 on the standard error