Added size suffixes

README.md

@@ -4,7 +4,7 @@ This is a C equivalent of the Python `main.py` script for reading data from True
 
 ## Overview
 
-The program reads random data from a TrueRNG device via serial port, counts the number of ones and zeros in the data, and saves the raw data to a binary file called `random.bin`.
+The program reads random data from a TrueRNG device via serial port, counts the number of ones and zeros in the data, and provides flexible output options including multiple formats and size specifications.
 
 ## Supported Devices
 
@@ -32,24 +32,83 @@ gcc -Wall -Wextra -std=c99 -O2 -o truerng main.c
 
 ## Usage
 
+### Basic Usage
+
 ```bash
 ./truerng
 ```
 
-The program will:
-1. Automatically detect connected TrueRNG devices
-2. Read 1024 blocks of 1024 bytes each (1MB total)
-3. Count ones and zeros in real-time
-4. Display read rate in KB/s
-5. Save raw data to `random.bin`
-6. Display final statistics
+### Command Line Options
+
+```bash
+./truerng [OPTIONS]
+```
+
+**Options:**
+- `-n, --bytes <N>` - Number of bytes to generate (default: 1048576)
+  - Supports size suffixes: K, MB, GB, TB (case-insensitive)
+  - Examples: `1024`, `1K`, `2.5MB`, `1GB`, `512k`, `1tb`
+- `-f, --format <FORMAT>` - Output format: binary, hex, base64, decimal
+  - Default: binary when piped, hex in interactive mode
+- `-o, --output <FILE>` - Output filename (works with all formats)
+- `-q, --quiet` - Suppress statistics/progress output
+- `-v, --verbose` - Show detailed device information
+- `-h, --help` - Show help message
+
+### Size Suffixes
+
+The `-n` option supports convenient size suffixes (case-insensitive):
+- **K** or **KB**: Kilobytes (1024 bytes)
+- **M** or **MB**: Megabytes (1,048,576 bytes)
+- **G** or **GB**: Gigabytes (1,073,741,824 bytes)
+- **T** or **TB**: Terabytes (1,099,511,627,776 bytes)
+
+Decimal values are supported: `1.5MB`, `2.5GB`, etc.
+
+### Examples
+
+```bash
+# Basic usage - interactive mode with hex output
+./truerng
+
+# Generate 1KB of data in hex format
+./truerng -n 1K -f hex
+
+# Generate 2.5MB and pipe to another program
+./truerng -n 2.5MB | xxd
+
+# Save 1GB of binary data to file quietly
+./truerng -n 1GB -o random.dat -q
+
+# Generate 512KB as hex and save to file
+./truerng -n 512K -f hex -o output.hex
+
+# Generate base64 output with verbose device info
+./truerng -n 1MB -f base64 -v
+
+# Backward compatibility - plain numbers still work
+./truerng -n 1048576 -f binary
+```
+
+### Output Formats
+
+- **binary**: Raw binary data (default for piped output)
+- **hex**: Hexadecimal representation (default for interactive mode)
+- **base64**: Base64 encoded output
+- **decimal**: Decimal byte values
+
+### Modes
+
+The program automatically detects the execution context:
+- **Interactive mode**: Shows progress, statistics, and defaults to hex output
+- **Piped mode**: Optimized for piping, defaults to binary output
+- **File output**: Can be combined with any format using `-o` option
 
 ## Configuration
 
-You can modify the following constants in [`main.c`](main.c:32):
+You can modify the following constants in [`main.c`](main.c:34):
 
 - `BLOCKSIZE`: Number of bytes to read per block (default: 1024)
-- `NUMLOOPS`: Number of blocks to read (default: 1024)
 
 ## Permissions
 
@@ -70,30 +129,77 @@ The C implementation:
 - Uses native Linux serial port APIs instead of pyserial
 - Implements USB device detection via sysfs
 - Uses lookup tables for efficient bit counting
+- Provides enhanced command line interface with size suffixes
+- Supports multiple output formats (binary, hex, base64, decimal)
 - Provides equivalent functionality with better performance
 
-## Output
+## Sample Output
 
-Sample output:
+### Interactive Mode
 ```
-TrueRNG Counting Ones vs Zeros Example
-http://ubld.it
+TrueRNG - True Random Number Generator
 ==================================================
-TrueRNG Found
-Using com port:  /dev/ttyUSB0
-Block Size:      1024 Bytes
-Number of loops: 1024
-Total size:      1048576 Bytes
-Writing to:      random.bin
-==================================================
-1048576 Bytes Read at  45.23 Kbytes/s
+TrueRNGproV2 Found
+Using port: /dev/ttyACM0
+Generating: 1024 bytes
+Starting data collection...
+1024/1024 Bytes Read at 504.19 Kbytes/s
 
 Results
 =======
-Total Ones : 4194234
-Total Zeros: 4194314
+Total time: 0.02 seconds
+Total Ones:  4072
+Total Zeros: 4120
+Total Bits:  8192
+Extra zeros: 48
+=======
+```
 
-Total Bits : 8388608
+### Piped Mode with Verbose
+```
+TrueRNG - True Random Number Generator
+Mode: Piped (Verbose)
+==================================================
+TrueRNGproV2 Found
+Using port: /dev/ttyACM0
+Generating: 2048 bytes
+Starting data collection...
+2048/2048 Bytes Read at 462.17 Kbytes/s
 
-There are 80 more zeros in the Capture!
-=======
+Results
+=======
+Total time: 0.04 seconds
+Total Ones:  8144
+Total Zeros: 8248
+Total Bits:  16392
+Extra zeros: 104
+=======
+```
+
+### Quiet Mode
+```bash
+./truerng -n 1K -o data.bin -q
+# No output - data saved silently to data.bin
+```
+
+### Help Output
+```bash
+./truerng --help
+TrueRNG - True Random Number Generator
+Usage: truerng [OPTIONS]
+
+Options:
+  -n, --bytes <N>          Number of bytes to generate (default: 1048576)
+                           Supports suffixes: K, MB, GB, TB (e.g., 1K, 2.5MB, 1GB)
+  -f, --format <FORMAT>    Output format: binary, hex, base64, decimal (default: binary when piped, interactive otherwise)
+  -o, --output <FILE>      Output filename (ignored in piped mode)
+  -q, --quiet              Suppress statistics/progress
+  -v, --verbose            Show detailed device information
+  -h, --help               Show this help message
+
+Examples:
+  truerng -n 1024 -f hex                    # Interactive mode with hex output
+  truerng -n 1K -f hex                      # Same as above using K suffix
+  truerng -n 2.5MB | xxd                    # Piped mode with MB suffix
+  truerng -n 1GB -o random.dat -q           # Save 1GB to file quietly
+  truerng -n 512K -f hex -o output.hex      # Save 512KB as hex to file

main.c

@@ -24,6 +24,7 @@
 #include <ctype.h>
 #include <sys/ioctl.h>
 #include <getopt.h>
+#include <limits.h>
 
 // Define CRTSCTS if not available
 #ifndef CRTSCTS
@@ -63,12 +64,71 @@ struct Options options;
 // Global variables
 static int ones_in_byte[256];
 
+// Parse byte size with optional suffix (K, MB, GB, TB)
+// Returns: parsed size in bytes, or -1 on error
+// Sets *error to 1 if parsing fails, 0 on success
+long long parse_byte_size(const char* size_str, int* error) {
+    if (!size_str || !error) {
+        if (error) *error = 1;
+        return -1;
+    }
+    
+    *error = 0;
+    char* endptr;
+    double value = strtod(size_str, &endptr);
+    
+    if (value < 0) {
+        *error = 1;
+        return -1;
+    }
+    
+    // If no suffix, return the value as bytes (backward compatibility)
+    if (*endptr == '\0') {
+        if (value > LLONG_MAX) {
+            *error = 1;
+            return -1;
+        }
+        return (long long)value;
+    }
+    
+    // Parse suffix (case-insensitive)
+    char suffix[4] = {0};
+    int i = 0;
+    while (*endptr && i < 3) {
+        suffix[i++] = toupper(*endptr++);
+    }
+    
+    // Determine multiplier
+    long long multiplier = 1;
+    if (strcmp(suffix, "K") == 0 || strcmp(suffix, "KB") == 0) {
+        multiplier = 1024LL;
+    } else if (strcmp(suffix, "M") == 0 || strcmp(suffix, "MB") == 0) {
+        multiplier = 1024LL * 1024LL;
+    } else if (strcmp(suffix, "G") == 0 || strcmp(suffix, "GB") == 0) {
+        multiplier = 1024LL * 1024LL * 1024LL;
+    } else if (strcmp(suffix, "T") == 0 || strcmp(suffix, "TB") == 0) {
+        multiplier = 1024LL * 1024LL * 1024LL * 1024LL;
+    } else {
+        *error = 1;
+        return -1;
+    }
+    
+    // Check for overflow
+    if (value > (double)LLONG_MAX / multiplier) {
+        *error = 1;
+        return -1;
+    }
+    
+    return (long long)(value * multiplier);
+}
+
 // Output format functions
 void output_binary(unsigned char *buffer, int bytes_read, FILE *out) {
     fwrite(buffer, 1, bytes_read, out);
 }
 
 void output_hex(unsigned char *buffer, int bytes_read, FILE *out, int piped) {
+    (void)piped; // Suppress unused parameter warning
     for (int i = 0; i < bytes_read; i++) {
         fprintf(out, "%02x", buffer[i]);
     }
@@ -77,6 +137,7 @@ void output_hex(unsigned char *buffer, int bytes_read, FILE *out, int piped) {
 }
 
 void output_decimal(unsigned char *buffer, int bytes_read, FILE *out, int piped) {
+    (void)piped; // Suppress unused parameter warning
     for (int i = 0; i < bytes_read; i++) {
         fprintf(out, "%d", buffer[i]);
     }
@@ -85,6 +146,7 @@ void output_decimal(unsigned char *buffer, int bytes_read, FILE *out, int piped)
 }
 
 void output_base64(unsigned char *buffer, int bytes_read, FILE *out, int piped) {
+    (void)piped; // Suppress unused parameter warning
     static const char b64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
     char encoded[5];
     for (int i = 0; i < bytes_read; i += 3) {
@@ -118,6 +180,7 @@ void print_usage(void) {
     printf("Usage: truerng [OPTIONS]\n\n");
     printf("Options:\n");
     printf("  -n, --bytes <N>          Number of bytes to generate (default: 1048576)\n");
+    printf("                           Supports suffixes: K, MB, GB, TB (e.g., 1K, 2.5MB, 1GB)\n");
     printf("  -f, --format <FORMAT>    Output format: binary, hex, base64, decimal (default: binary when piped, interactive otherwise)\n");
     printf("  -o, --output <FILE>      Output filename (ignored in piped mode)\n");
     printf("  -q, --quiet              Suppress statistics/progress\n");
@@ -125,8 +188,10 @@ void print_usage(void) {
     printf("  -h, --help               Show this help message\n");
     printf("\nExamples:\n");
     printf("  truerng -n 1024 -f hex                    # Interactive mode with hex output\n");
-    printf("  truerng -n 1024 | xxd                     # Piped mode to hex viewer\n");
-    printf("  truerng -o random.dat -q                 # Save to file quietly\n");
+    printf("  truerng -n 1K -f hex                      # Same as above using K suffix\n");
+    printf("  truerng -n 2.5MB | xxd                    # Piped mode with MB suffix\n");
+    printf("  truerng -n 1GB -o random.dat -q           # Save 1GB to file quietly\n");
+    printf("  truerng -n 512K -f hex -o output.hex      # Save 512KB as hex to file\n");
 }
 
 int parse_arguments(int argc, char *argv[]) {
@@ -152,13 +217,15 @@ int parse_arguments(int argc, char *argv[]) {
     int option_index = 0;
     while ((opt = getopt_long(argc, argv, opt_string, long_options, &option_index)) != -1) {
         switch (opt) {
-            case 'n':
-                options.bytes = atol(optarg);
-                if (options.bytes <= 0) {
-                    fprintf(stderr, "Error: Bytes must be positive\n");
+            case 'n': {
+                int parse_error;
+                options.bytes = parse_byte_size(optarg, &parse_error);
+                if (parse_error || options.bytes <= 0) {
+                    fprintf(stderr, "Error: Invalid byte size '%s'. Use a positive number optionally followed by K, MB, GB, or TB\n", optarg);
                     return -1;
                 }
                 break;
+            }
             case 'f':
                 if (strcmp(optarg, "binary") == 0) options.format = BINARY;
                 else if (strcmp(optarg, "hex") == 0) options.format = HEX;
@@ -199,6 +266,7 @@ int find_truerng_port(char* port_path, int piped, int verbose);
 int setup_serial_port(const char* port_path);
 int read_usb_device_info(const char* port_name, char* vid, char* pid);
 double get_time_diff(struct timeval start, struct timeval end);
+long long parse_byte_size(const char* size_str, int* error);
 int parse_arguments(int argc, char *argv[]);
 void print_usage(void);
 int is_piped(void);
@@ -573,7 +641,9 @@ cleanup:
     // Reset terminal min setting
     char stty_cmd[MAX_PATH + 20];
     snprintf(stty_cmd, sizeof(stty_cmd), "stty -F %s min 1", port_path);
-    system(stty_cmd);  // Ignore failure
+    if (system(stty_cmd) != 0) {
+        // Ignore failure - this is just cleanup
+    }
 
     return 0;
 }

test_output.hex

@@ -1 +0,0 @@
-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