Print statement not outputting result - c

Question

Very new to programming will appreciate the help.
I have the following program to count words that are input in the command line
for example:
> ./main cat nap dog
Given input:
cat
.
Expected output:
Looking for 3 words
Result:
cat:1
nap:0
dog:0
This is the code I've written for it :
#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 (fgets(buffer,sizeof(buffer),stdin)) {
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)
{
fprintf(stdout,"Result:\n");
for(int i=0; i <=entry_count;i++){
printf("%s:%d\n", entries[i].word, entries[i].counter);
}
}
void printHelp(const char *name)
{
fprintf(stderr,"usage: %s [-h] <word1> ... <wordN>\n", name);
}
int main(int argc, char **argv)
{
const char *prog_name = *argv;
WordCountEntry entries[argc];
int entryCount = 0;
while ((*argv) != NULL) {
if (**argv == '-') {
switch ((*argv)[1]) {
case 'h':
printHelp(prog_name);
break;
case'f':
freopen((*argv)[2],"w",stdout);
break;
default:
fprintf(stderr,"%s: Invalid option %s. Use -h for help.\n",
prog_name, *argv);
}
} else {
if (entryCount < argc-1) {
entries[entryCount].word = *argv;
entries[entryCount++].counter = 0;
}
}
argv++;
}
if (entryCount == 0) {
fprintf(stderr,"%s: Please supply at least one word. Use -h for help.\n",
prog_name);
return EXIT_FAILURE;
}
if (entryCount == 1) {
fprintf(stdout,"Looking for a single word\n");
} else {
fprintf(stdout,"Looking for %d words\n", entryCount);
}
process_stream(entries, entryCount);
print_result(entries, entryCount);
return EXIT_SUCCESS;
}
I can't seem to figure out why the print_result function does not output even the "Result:" statement

Answer 1

You are making things much harder on yourself than it need be. While you are free to use pointer arithmetic to iterate over the strings in argv until you reach the sentinel nul, you are far better served iterating for (i = 1; i < argc; i++), using array indexing for that purpose. (don't forget that the first entry, index 0 is the program name).
Your use of freopen as is will completely obscure all output for your program. Instead of calling freopen when you test for -f, it would be better to set a save filename variable. Then when you output your results, you simply test whether there is an output filename and if so, make a simple call to fopen. I'll leave you to think about the implementation.
As mentioned in comments, fgets reads up to and including the '\n' and includes the newline in the buffer. In order to compare entries[x].word with buffer, you need to remove the trailing '\n' before the comparison because your current comparison will never match, e.g.:
strcmp ("foo", "foo\n")
Lastly the loop logic is just a bit muddled. You are free to do it any way that works, but keeping it simple and clean will greatly help you keep the indexing straight in your mind.
Putting those pieces of the puzzle together, you could make a relative few changes and do the following:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* Structures */
typedef struct {
char *word;
int counter;
} WordCountEntry;
int process_stream (WordCountEntry entries[], int entry_count)
{
short line_count = 0;
char buffer[30];
while (fgets (buffer, sizeof (buffer), stdin)) {
if (*buffer == '.')
break;
/* strip trailing '\n' from buffer */
size_t len = strlen (buffer); /* get word length */
if (buffer[len - 1] == '\n') /* check for '\n' */
buffer[--len] = 0; /* overwrite with nul-byte */
/* Compare against each entry */
if (!strcmp (entries[line_count].word, buffer))
entries[line_count].counter++;
if (++line_count == entry_count)
break;
}
return line_count;
}
void print_result (WordCountEntry entries[], int entry_count)
{
fprintf (stdout, "\nResult:\n");
for (int i = 0; i < entry_count; i++) {
printf ("%s:%d\n", entries[i].word, entries[i].counter);
}
}
void printHelp (const char *name)
{
fprintf (stderr, "usage: %s [-h] <word1> ... <wordN>\n", name);
}
int main (int argc, char **argv)
{
const char *prog_name = *argv;
WordCountEntry entries[argc];
int entryCount = 0;
for (int i = 1; i < argc; i++) {
if (*argv[i] == '-') {
switch (argv[i][1]) {
case 'h':
printHelp (prog_name);
break;
default:
fprintf (stderr, "%s: Invalid option %s. Use -h for help.\n",
prog_name, *argv);
}
}
else {
entries[entryCount].word = argv[i];
entries[entryCount++].counter = 0;
}
}
if (!entryCount) {
fprintf (stderr,
"%s: Please supply at least one word. Use -h for help.\n",
prog_name);
return EXIT_FAILURE;
}
if (entryCount == 1) {
fprintf (stdout, "Looking for a single word\n");
}
else {
fprintf (stdout, "Looking for %d words\n", entryCount);
}
process_stream (entries, entryCount);
print_result (entries, entryCount);
return EXIT_SUCCESS;
}
note: if you using C89, then you will need to independently declare i outside:
for (int i = 0; i < entry_count; i++) {
Example Use/Output
$ ./bin/printfissue one two three "four and a half" five
Looking for 5 words
one
two
three
four and a half
five
Result:
one:1
two:1
three:1
four and a half:1
five:1
Look things over and let me know if you have further questions. There are many different ways to do the loops and indexing, so this isn't meant to be the only way you can do it, or even the most right way to do it for that matter.

Answer 2

Put fflush(stdout); at the end of your main function. That should flush out everything to the standard output.