Remove useless header file, add working Makefile and comments

mygrep/Makefile

@@ -0,0 +1,14 @@
+CC = gcc
+CFLAGS = -std=c99 -pedantic -Wall -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_SVID_SOURCE -D_POSIX_C_SOURCE=200809L -g -c
+TARGET = mygrep
+
+all: $(TARGET).c 
+	$(CC) $(CFLAGS) $(TARGET).c
+	$(CC) $(TARGET).o -o $(TARGET)
+
+install:
+	cp $(TARGET) /usr/local/bin/$(TARGET)
+
+clean:
+	$(RM) $(TARGET).o
+	$(RM) $(TARGET)

mygrep/mygrep.c

@@ -3,10 +3,13 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
-#include "mygrep.h"
 
-void main(int argc, char *argv[]) {
-    check_opts_number(argc, argv);
+static void print_usage(void);
+static void check_opts_number(int argc);
+static void check_for_string(char *to_check, char *to_find, int iflag, char *ofile);
+
+int main(int argc, char *argv[]) {
+    check_opts_number(argc);
 
     int iflag = 0;
     char *ofile = NULL;
@@ -38,7 +41,7 @@ void main(int argc, char *argv[]) {
 
      // Check if the required argument is there
     if(argv[optind] == NULL) {
-        printf("Mandatory argument 'keyword' missing.\n");
+        fprintf(stderr, "Mandatory argument 'keyword' missing.\n");
         print_usage();
         exit(EXIT_FAILURE);
     } else {
@@ -60,7 +63,7 @@ void main(int argc, char *argv[]) {
     if(filename != NULL) {
         FILE *in;
         if((in = fopen(filename, "r")) == NULL) {
-            printf("Error opening the file %s\n", filename);
+            fprintf(stderr, "Error opening the file %s\n", filename);
             exit(EXIT_FAILURE);
         }
 
@@ -73,15 +76,22 @@ void main(int argc, char *argv[]) {
         }
     }
 
-    exit(EXIT_SUCCESS);
+    return EXIT_SUCCESS;
 }
 
-void print_usage() {
+static void print_usage(void) {
     printf("mygrep [-i] [-o outfile] keyword [file...]\n");
 }
 
-// Check for coorect number of options
-void check_opts_number(int argc, char *argv[]) {
+/**
+ * @brief Function to check the number of arguments
+ * @details Checks the number of arguments supplied to the command line. 
+ *          If the arguments are less than the required or more than possible, it exits
+ * @param argc Number of arguments obtained from the command line
+ * @return none 
+ * 
+ **/
+static void check_opts_number(int argc) {
     if(argc <= 1) {
         fprintf(stderr, "At least one argument expected.\n");
         print_usage();
@@ -93,7 +103,21 @@ void check_opts_number(int argc, char *argv[]) {
     }
 }
 
-void check_for_string(char *to_check, char *to_find, int iflag, char *ofile) {
+/**
+ * @brief Function to check whether or not a string is contained in another string
+ * @details Checks whether or not a substring is contained in a line. 
+ *          If it is there and no output file is passed, it will print the line to stdout
+ *          If it is there and an output file is passed, it will append the line to the end of the output file
+ * 
+ * @param
+ *      to_check: String to be checked against
+ *      to_find: String to search for
+ *      iflag: Whether or not to ignore the casing of the letters
+ *      ofile: The file to append the output to
+ * @return none
+ * 
+ **/
+static void check_for_string(char *to_check, char *to_find, int iflag, char *ofile) {
     if(ofile == NULL) {
         /**
          * Find the first occurance of needle in haystack and return it as a pointer.
@@ -112,7 +136,7 @@ void check_for_string(char *to_check, char *to_find, int iflag, char *ofile) {
 
         // Check if the file was opened successfully
         if((out = fopen(ofile, "a")) == NULL) {
-            printf("Error opening the file %s\n", ofile);
+            fprintf(stderr, "Error opening the file %s\n", ofile);
             exit(EXIT_FAILURE);
         }
 

mygrep/mygrep.h

@@ -1,8 +0,0 @@
-#ifndef MYGREP_HEADER
-#define MYGREP_HEADER
-
-void print_usage();
-void check_opts_number(int argc, char *argv[]);
-void check_for_string(char *to_check, char *to_find, int iflag, char *ofile);
-
-#endif