Add comments to mygrep, begin implementing the http client

mygrep/Makefile

@@ -2,7 +2,7 @@ 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 
+all: $(TARGET).c
 	$(CC) $(CFLAGS) $(TARGET).c
 	$(CC) $(TARGET).o -o $(TARGET)
 

mygrep/mygrep.c

@@ -1,3 +1,32 @@
+/**
+ * @file mygrep.c
+ * @author Ivaylo Ivanov 11777707
+ * @date 03.11.2018
+ *
+ * @brief Main program module.
+ *
+ * A reduced variation of the Unix-command `grep`.
+ * It reads in several files and prints all lines containing a keyword.
+ *
+ *    SYNOPSIS
+ *    mygrep [-i] [-o outfile] keyword [file...]
+ *
+ * The program `mygrep` reads files line by line and for each line checks whether it contains the search
+ * term keyword. The line is printed if it contains the keyword, otherwise it is not printed.
+ * The program accepts lines of any length.
+ *
+ * If one or multiple input files are specified (given as positional arguments after keyword), then mygrep
+ * reads each of them in the order they are given. If no input file is specified, the program reads from
+ * `stdin`.
+ *
+ * If the option `-o` is given, the output is written to the specified file (outfile). Otherwise, the output is
+ * written to `stdout`.
+ *
+ * If the option `-i` is given, the program does not differentiate between lower and upper case letters, i.e.
+ * the search for the keyword in a line is case insensitive.
+ *
+ **/
+
 #define _GNU_SOURCE ///< in order for strcasestr to work
 #include <stdio.h>
 #include <stdlib.h>
@@ -85,11 +114,11 @@ static void print_usage(void) {
 
 /**
  * @brief Function to check the number of arguments
- * @details Checks the number of arguments supplied to the command line. 
+ * @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 
- * 
+ * @return none
+ *
  **/
 static void check_opts_number(int argc) {
     if(argc <= 1) {
@@ -105,17 +134,17 @@ static void check_opts_number(int argc) {
 
 /**
  * @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. 
+ * @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) {