diff --git a/arrToBin.c b/arrToBin.c
index 95480d0..8fa42bd 100644
--- a/arrToBin.c
+++ b/arrToBin.c
@@ -21,7 +21,6 @@ int main(){
         bin[i] = b;
     }
     for(int j = 0; j < 16; j++){
-        if(
             printf("%d", bin[j]);
     }
     printf("\n");
diff --git a/bin/7-teiler b/bin/7-teiler
index 34a678a..b140f42 100755
Binary files a/bin/7-teiler and b/bin/7-teiler differ
diff --git a/bin/7teiler b/bin/7teiler
index 1d7b37a..fbcb6ab 100755
Binary files a/bin/7teiler and b/bin/7teiler differ
diff --git a/bin/abc b/bin/abc
new file mode 100755
index 0000000..d3bb158
Binary files /dev/null and b/bin/abc differ
diff --git a/bin/adder b/bin/adder
index e19edf5..5e39703 100755
Binary files a/bin/adder and b/bin/adder differ
diff --git a/bin/args b/bin/args
index 820fca2..a7e68bf 100755
Binary files a/bin/args and b/bin/args differ
diff --git a/bin/arrToBin b/bin/arrToBin
new file mode 100755
index 0000000..0deafc7
Binary files /dev/null and b/bin/arrToBin differ
diff --git a/bin/ascii b/bin/ascii
index 90dad55..48d1bb8 100755
Binary files a/bin/ascii and b/bin/ascii differ
diff --git a/bin/calculator b/bin/calculator
index c32eeb4..0532a62 100755
Binary files a/bin/calculator and b/bin/calculator differ
diff --git a/bin/callreference b/bin/callreference
index e3a1a22..ef22d0c 100755
Binary files a/bin/callreference and b/bin/callreference differ
diff --git a/bin/complex b/bin/complex
index d1c20c7..bd65b20 100755
Binary files a/bin/complex and b/bin/complex differ
diff --git a/bin/echo b/bin/echo
index ce19f57..aab6123 100755
Binary files a/bin/echo and b/bin/echo differ
diff --git a/bin/echochar b/bin/echochar
index 2455112..a4dcf34 100755
Binary files a/bin/echochar and b/bin/echochar differ
diff --git a/bin/euler b/bin/euler
index 8394326..aaa2c6b 100755
Binary files a/bin/euler and b/bin/euler differ
diff --git a/bin/factorial b/bin/factorial
index 37d2cf7..846865b 100755
Binary files a/bin/factorial and b/bin/factorial differ
diff --git a/bin/fail b/bin/fail
index 1f8ed41..d1870bb 100755
Binary files a/bin/fail and b/bin/fail differ
diff --git a/bin/fread b/bin/fread
index bdd5260..9982c7f 100755
Binary files a/bin/fread and b/bin/fread differ
diff --git a/bin/hello-world b/bin/hello-world
index 5a5e3b4..7c58e0b 100755
Binary files a/bin/hello-world and b/bin/hello-world differ
diff --git a/bin/options b/bin/options
index a4fefca..a6c7ac3 100755
Binary files a/bin/options and b/bin/options differ
diff --git a/bin/pointer-arithmetic b/bin/pointer-arithmetic
index 4cd2010..035208b 100755
Binary files a/bin/pointer-arithmetic and b/bin/pointer-arithmetic differ
diff --git a/bin/pointermagic b/bin/pointermagic
index 652da0a..02a2360 100755
Binary files a/bin/pointermagic and b/bin/pointermagic differ
diff --git a/bin/primenumbers b/bin/primenumbers
index b7910ae..4278733 100755
Binary files a/bin/primenumbers and b/bin/primenumbers differ
diff --git a/bin/quersumme b/bin/quersumme
index ddbd5c2..0285516 100755
Binary files a/bin/quersumme and b/bin/quersumme differ
diff --git a/bin/readfile b/bin/readfile
index b9f4712..c2209a6 100755
Binary files a/bin/readfile and b/bin/readfile differ
diff --git a/bin/redefinition b/bin/redefinition
index 5d35564..29116b9 100755
Binary files a/bin/redefinition and b/bin/redefinition differ
diff --git a/bin/redefinition-if b/bin/redefinition-if
index ca6de8e..b69b4d2 100755
Binary files a/bin/redefinition-if and b/bin/redefinition-if differ
diff --git a/bin/return-specified b/bin/return-specified
index 406b9d4..d860bc7 100755
Binary files a/bin/return-specified and b/bin/return-specified differ
diff --git a/bin/scanf-test b/bin/scanf-test
index f9a18f0..ac23d91 100755
Binary files a/bin/scanf-test and b/bin/scanf-test differ
diff --git a/bin/scnaf-hex-test b/bin/scnaf-hex-test
index 63669dd..f5cb2e0 100755
Binary files a/bin/scnaf-hex-test and b/bin/scnaf-hex-test differ
diff --git a/bin/signed-to-unsigned b/bin/signed-to-unsigned
index 6684e2d..988e7a8 100755
Binary files a/bin/signed-to-unsigned and b/bin/signed-to-unsigned differ
diff --git a/bin/sizeofs b/bin/sizeofs
index e4b4f63..8abe52c 100755
Binary files a/bin/sizeofs and b/bin/sizeofs differ
diff --git a/bin/success b/bin/success
index 4fc9eb4..6442220 100755
Binary files a/bin/success and b/bin/success differ
diff --git a/bin/sum b/bin/sum
index f85bb80..a47e9d8 100755
Binary files a/bin/sum and b/bin/sum differ
diff --git a/bin/tabtest b/bin/tabtest
index 2b28928..aa8bbe0 100755
Binary files a/bin/tabtest and b/bin/tabtest differ
diff --git a/bin/umlaut b/bin/umlaut
index 0ab933f..f7f9025 100755
Binary files a/bin/umlaut and b/bin/umlaut differ
diff --git a/bin/unary-double-not b/bin/unary-double-not
index ca7b6d6..7597fca 100755
Binary files a/bin/unary-double-not and b/bin/unary-double-not differ
diff --git a/compile-all.sh b/compile-all.sh
index f831cf7..a87e883 100755
--- a/compile-all.sh
+++ b/compile-all.sh
@@ -1,3 +1,13 @@
 #!/bin/bash
-echo "compiling all files in working directory $(pwd)"
-for file in $(/bin/ls); do ./compile.sh $file; done
+returnCode=0
+echo -e "compiling all files in working directory $(pwd)\n"
+for file in $(/bin/ls *.c); 
+do 
+    ./compile.sh $file; 
+    if [ "$?" -ne 0 ]
+    then
+        echo -e "\nERROR: could not compile $file !\n";
+        returnCode=1;
+    fi
+done
+exit $returnCode
diff --git a/compile-and-run.sh b/compile-and-run.sh
index a79cf6b..ccd5cea 100755
--- a/compile-and-run.sh
+++ b/compile-and-run.sh
@@ -1,4 +1,4 @@
 #!/bin/bash
 noext=$(echo "$1" | cut -f 1 -d '.')
-gcc $1 -o bin/$noext
+./compile $1
 ./bin/$noext $2 $3 $4 $5 $6 $7 $8 $9
diff --git a/compile.sh b/compile.sh
index c0373ff..cfad674 100755
--- a/compile.sh
+++ b/compile.sh
@@ -1,4 +1,4 @@
 #!/bin/bash
-echo "compiling $1..."
+echo "compiling $1 ..."
 noext=$(echo "$1" | cut -f 1 -d '.')
-gcc $1 -o bin/$noext
+gcc $1 -o bin/$noext -lm
diff --git a/echo.c b/echo.c
index 8278ea0..8a35260 100644
--- a/echo.c
+++ b/echo.c
@@ -2,7 +2,16 @@
 
 int main() {
 	char s[100];
-	gets(s);
+    //gets(s);
+    /*
+     * Never use gets().  Because it is impossible to tell without knowing the data in advance how many characters gets() will read,  and  be‐
+     * cause gets() will continue to store characters past the end of the buffer, it is extremely dangerous to use.  It has been used to break
+     * computer security.  Use fgets() instead.
+     *
+     * For more information, see CWE-242 (aka "Use of Inherently Dangerous Function") at http://cwe.mitre.org/data/definitions/242.html
+     *
+     */
+    fgets(s, sizeof(s), stdin);
 	printf("%s\n", s);
 	return 0;
 }