Add function for parsing arguments

Signed-off-by: Piotr Nowicki <piotr.nowicki@arm.com>

programs/ssl/ssl_base64_dump.c

@@ -19,8 +19,134 @@
  *  This file is part of mbed TLS (https://tls.mbed.org)
  */
 
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+
+/*
+ * This program version
+ */
+#define PROG_NAME "ssl_base64_dump"
+#define VER_MAJOR 0
+#define VER_MINOR 1
+
+/*
+ * Global values
+ */
+FILE *b64_file = NULL;      /* file with base64 codes to deserialize */
+char debug = 0;             /* flag for debug messages */
+
+/*
+ * Basic printing functions
+ */
+void print_version( )
+{
+    printf( "%s v%d.%d\n", PROG_NAME, VER_MAJOR, VER_MINOR );
+}
+
+void print_usage( )
+{
+    print_version();
+    printf(
+        "Usage:\n"
+        "\t-f path - Path to the file with base64 code\n"
+        "\t-v      - Show version\n"
+        "\t-h      - Show this usage\n"
+        "\t-d      - Print more information\n"
+        "\n"
+    );
+}
+
+void printf_dbg( const char *str, ... )
+{
+    if( debug )
+    {
+        va_list args;
+        va_start( args, str );
+        printf( "debug: " );
+        vprintf( str, args );
+        fflush( stdout );
+        va_end( args );
+    }
+}
+
+void printf_err( const char *str, ... )
+{
+    va_list args;
+    va_start( args, str );
+    fprintf( stderr, "ERROR: " );
+    vfprintf( stderr, str, args );
+    fflush( stderr );
+    va_end( args );
+}
+
+/*
+ * Exit from the program in case of error
+ */
+void error_exit()
+{
+    if( NULL != b64_file )
+    {
+        fclose( b64_file );
+    }
+    exit( -1 );
+}
+
+/*
+ * This function takes the input arguments of this program
+ */
+void parse_arguments( int argc, char *argv[] )
+{
+    int i = 1;
+
+    if( argc < 2 )
+    {
+        print_usage();
+        error_exit();
+    }
+
+    while( i < argc )
+    {
+        if( strcmp( argv[i], "-d" ) == 0 )
+        {
+            debug = 1;
+        }
+        else if( strcmp( argv[i], "-h" ) == 0 )
+        {
+            print_usage();
+        }
+        else if( strcmp( argv[i], "-v" ) == 0 )
+        {
+            print_version();
+        }
+        else if( strcmp( argv[i], "-f" ) == 0 )
+        {
+            if( ++i >= argc )
+            {
+                printf_err( "File path is empty\n" );
+                error_exit();
+            }
+
+            if( ( b64_file = fopen( argv[i], "r" ) ) == NULL )
+            {
+                printf_err( "Cannot find file \"%s\"\n", argv[i] );
+                error_exit();
+            }
+        }
+        else
+        {
+            print_usage();
+            error_exit();
+        }
+
+        i++;
+    }
+}
+
 int main( int argc, char *argv[] )
 {
+    parse_arguments( argc, argv );
 
     return 0;
 }