try

a2/Makefile

@@ -0,0 +1,11 @@
+# variables
+CC=gcc
+CFLAGS=-std=c11 -Wall -Werror
+LDLIBS=-lm
+OUTPUT=$@
+
+# targets
+%: %.c
+	$(CC) $(CFLAGS) $@.c $(LDLIBS) -o $(OUTPUT)
+
+

sk2a/Makefile

@@ -0,0 +1,16 @@
+CC = gcc
+CFLAGS = -g -Wall -Werror
+
+all: program
+
+program: compressor.o main.o
+	$(CC) $(CFLAGS) compressor.o main.o -o program
+
+compressor.o: compressor.c
+	$(CC) $(CFLAGS) -c compressor.c -o compressor.o
+
+main.o: main.c
+	$(CC) $(CFLAGS) -c main.c -o main.o
+
+clean:
+	rm -rf program *.o *.exe *.exe.stackdump

sk2a/compressor.c

@@ -0,0 +1,81 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "compressor.h"
+#define BUFSIZE 1024
+
+
+int ByteRLEEncode(char* bufferIn, int size, char* bufferOut) {
+    int posIn = 0, count = 1, posOut = 0;
+    char byteCurrent, byteRLE = bufferIn[posIn++];
+
+    while (posIn != size) {
+        byteCurrent = bufferIn[posIn++];
+
+        if (byteCurrent == byteRLE) {
+            count++;
+
+            if (count == 256) {
+                bufferOut[posOut++] = byteRLE;
+                bufferOut[posOut++] = 255;
+
+                count = 1;
+            }
+        } else {
+            bufferOut[posOut++] = byteRLE;
+            bufferOut[posOut++] = count;
+
+            byteRLE = byteCurrent;
+            count = 1;
+        }
+    }
+
+    bufferOut[posOut++] = byteRLE;
+    bufferOut[posOut++] = count;
+
+    return posOut;
+}
+
+int mycompress(char* bufferIn, int size, char* bufferOut){
+    return ByteRLEEncode(bufferIn, size, bufferOut);;
+}
+
+
+void compress(FILE *infile, FILE *outfile){
+    char buffer[BUFSIZE];
+    memset(buffer,0,BUFSIZE);
+    while(1){
+        int insize = fread(buffer,sizeof(char),BUFSIZE,infile);
+        if (insize == 0){
+            if (feof(infile)){
+                // end of file
+                break;
+            }
+            assert(!ferror(infile));
+        }
+        char outbuf[BUFSIZE*2];
+        // Doplnte implementaciu kompresie. 
+        int outsize = mycompress(buffer,insize,outbuf);
+        if (outsize   > 0){
+            fwrite(outbuf,sizeof(char),outsize,outfile);
+        }
+    }
+}
+
+
+void decompress(FILE *infile, FILE *outfile){
+    unsigned char RLEMetadata[2];
+    char RLEData[255];
+
+    while (fread(RLEMetadata, 2, 1, infile)) {
+        printf("%c %d\n", RLEMetadata[0], RLEMetadata[1]);
+
+        for (int i = 0; i < RLEMetadata[1]; i++) {
+            RLEData[i] = RLEMetadata[0];
+        }
+
+        fwrite(RLEData, RLEMetadata[1], 1, outfile);
+    }
+}
+

sk2a/compressor.h

@@ -0,0 +1,18 @@
+#ifndef _COMPRESSORH
+#define _COMPRESSORH
+#include <stdio.h>
+
+/**
+ * Skomprimuje súbor in a zapíše do súboru out.
+ * @arg in smerník na otvorený vstupný súbor (na čítanie)
+ * @arg out smerník na otvorený výstupný súbor (na zápis)
+ */
+void compress(FILE* in, FILE* out);
+/**
+ * Dekomprimuje súbor in a zapíše do súboru out.
+ * @arg in smerník na otvorený vstupný súbor (na čítanie)
+ * @arg out smerník na otvorený výstupný súbor (na zápis)
+ */
+void decompress(FILE* in, FILE* out);
+
+#endif

sk2a/main.c

@@ -0,0 +1,24 @@
+#include "compressor.h"
+
+int main(int argc,char** argv){
+    if (argc != 4 || (argv[1][1] != 'c' && argv[1][1] != 'd')){
+        printf("Usage: \n");
+        printf("  Compress ./compress -c infile.txt outfile.compress\n");
+        printf("  decompress ./compress -d outfile.compress infile.txt\n");
+        return 0;
+    }
+    char* action = argv[1];
+    char* infile = argv[2];
+    char* outfile = argv[3];
+    FILE* inf = fopen(infile,"r");
+    FILE* outf = fopen(outfile,"w");
+    if (action[1] == 'c'){
+        compress(inf,outf);
+    }
+    else if (action[1] == 'd'){
+        decompress(inf,outf);
+    }
+    fclose(inf);
+    fclose(outf);
+}
+