I am so lost....any help would be apperciate on how to answert this five questions: 1) Alter the program such that only the corect output is sent to the standard output stream (stdout), while error and help messages are sent to the standard error stream (stderr). (hint use fprintf.)

2)Implement an option command-line switch '-fFILENAME' that sends program output to a file named FILENAME.

3) Add support for matching arbitrary number of words, not just 5. (Hint: use malloc, and dont worry to much about memory efficiency).

4) Safeguard the program from buffer overflow attacks. (Hint: 'gets' is BAD. Use fgets isntead, which specifies the maxium number oc characters to be read in.)

5) Allow multiple words to be specified per line (Understand Strtok. Be careful about the newline chatacter ' ' at the end of the line.)

BELOW is the output of the program. It is a counting words program and should ouput what is below expected output.

/* About this program: - This program counts words. - The specific words that will be counted are passed in as command-line arguments. - The program reads words (one word per line) from standard input until EOF or an input line starting with a dot '.' - The program prints out a summary of the number of times each word has appeared. - Various command-line options alter the behavior of the program.

E.g., count the number of times 'cat', 'nap' or 'dog' appears. > ./main cat nap dog Given input: cat . Expected output: Looking for 3 words Result: cat:1 nap:0 dog:0 */

#include #include #include #include "smp0_tests.h"

#define LENGTH(s) (sizeof(s) / sizeof(*s))

/* Structures */ typedef struct { char *word; int counter; } WordCountEntry;

int process_stream(WordCountEntry entries[], int entry_count) { short line_count = 0; char buffer[30];

while (gets(buffer)) { if (*buffer == '.') break; /* Compare against each entry */ int i = 0; while (i < entry_count) { if (!strcmp(entries[i].word, buffer)) entries[i].counter++; i++; } line_count++; } return line_count; }

void print_result(WordCountEntry entries[], int entry_count) { printf("Result: "); while (entry_count-- > 0) { printf("%s:%d ", entries->word, entries->counter); } }

void printHelp(const char *name) { printf("usage: %s [-h] ... ", name); }

int main(int argc, char **argv) { const char *prog_name = *argv;

WordCountEntry entries[5]; int entryCount = 0;

/* Entry point for the testrunner program */ if (argc > 1 && !strcmp(argv[1], "-test")) { run_smp0_tests(argc - 1, argv + 1); return EXIT_SUCCESS; }

while (*argv != NULL) { if (**argv == '-') {

switch ((*argv)[1]) { case 'h': printHelp(prog_name); default: printf("%s: Invalid option %s. Use -h for help. ", prog_name, *argv); } } else { if (entryCount < LENGTH(entries)) { entries[entryCount].word = *argv; entries[entryCount++].counter = 0; } } argv++; } if (entryCount == 0) { printf("%s: Please supply at least one word. Use -h for help. ", prog_name); return EXIT_FAILURE; } if (entryCount == 1) { printf("Looking for a single word "); } else { printf("Looking for %d words ", entryCount); }

process_stream(entries, entryCount); print_result(entries, entryCount);

return EXIT_SUCCESS; }