From 36420488a1172f2a976b0c65dcd325794f100615 Mon Sep 17 00:00:00 2001
From: Ivaylo Ivanov <i_a_ivanov@mail.bg>
Date: Sat, 6 Oct 2018 17:23:33 +0200
Subject: [PATCH] Add argument handling and a README for mygrep

---
 .gitignore       |  3 ++-
 mygrep/README.md | 23 +++++++++++++++++
 mygrep/mygrep.c  | 67 ++++++++++++++++++++++++++++++++++++++++++++++--
 mygrep/mygrep.h  |  8 ++++++
 4 files changed, 98 insertions(+), 3 deletions(-)
 create mode 100644 mygrep/mygrep.h

diff --git a/.gitignore b/.gitignore
index dbe9c82..c047fbc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
-.vscode/
\ No newline at end of file
+.vscode/
+*.out
diff --git a/mygrep/README.md b/mygrep/README.md
index e69de29..cead972 100644
--- a/mygrep/README.md
+++ b/mygrep/README.md
@@ -0,0 +1,23 @@
+# mygrep
+
+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.
+
+**Note: The description is from the task I got from TU.**
\ No newline at end of file
diff --git a/mygrep/mygrep.c b/mygrep/mygrep.c
index 5a7647a..672fa7d 100644
--- a/mygrep/mygrep.c
+++ b/mygrep/mygrep.c
@@ -1,5 +1,68 @@
 #include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "mygrep.h"
 
-void main() {
-    printf("Hello, World!");
+void main(int argc, char *argv[]) {
+    check_opts_number(argc, argv);
+
+    int iflag = 0;
+    char *ofile = NULL;
+    char *keyword = NULL;
+    char *filename = NULL;
+    int c;
+
+    while((c = getopt(argc, argv, "io:h")) != -1) {
+        switch(c) {
+            case 'i':
+                iflag = 1;
+                break;
+            case 'o':
+                ofile = optarg;
+                break;
+            case 'h':
+                print_usage();
+                break;
+            case '?':
+                print_usage();
+                exit(EXIT_FAILURE);
+            default:
+                abort();
+        }
+    }
+
+    if(argv[optind] == NULL) {
+        printf("Mandatory argument 'keyword' missing.\n");
+        print_usage();
+        exit(EXIT_FAILURE);
+    } else {
+        keyword = argv[optind];
+        filename = argv[optind + 1];
+    }
+
+    if(filename == NULL) {
+        check_for_string("test", keyword);
+    }
+
+    exit(EXIT_SUCCESS);
+}
+
+void print_usage() {
+    printf("mygrep [-i] [-o outfile] keyword [file...]\n");
+}
+
+void check_opts_number(int argc, char *argv[]) {
+    if(argc <= 1) {
+        fprintf(stderr, "At least one argument expected.\n");
+        print_usage();
+        exit(EXIT_FAILURE);
+    } else if(argc > 6) {
+        fprintf(stderr, "Too many arguments supplied.\n");
+        print_usage();
+        exit(EXIT_FAILURE);
+    }
+}
+
+void check_for_string(char *to_check, char *to_find) {
+    printf("Not implemented. This function will search for the substring %s in the string %s.\n", to_find, to_check);
 }
diff --git a/mygrep/mygrep.h b/mygrep/mygrep.h
new file mode 100644
index 0000000..cbdbe92
--- /dev/null
+++ b/mygrep/mygrep.h
@@ -0,0 +1,8 @@
+#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);
+
+#endif
\ No newline at end of file