diff --git a/Makefile b/Makefile
index 44cad7e..fd4c2bc 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,11 @@
 
-.PHONY: honeywell-config clean
+.PHONY: honeywell-config debug clean
 
 honeywell-config:
 	gcc -Wall -Werror -o honeywell-config honeywell-config.c -lusb-1.0
 
+debug:
+	gcc -Wall -Werror -O0 -ggdb3 -o honeywell-config honeywell-config.c -lusb-1.0
+
 clean:
 	rm -f honeywell-config
diff --git a/honeywell-config.c b/honeywell-config.c
index e177b51..14ac575 100644
--- a/honeywell-config.c
+++ b/honeywell-config.c
@@ -1,7 +1,10 @@
+#include <ctype.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>
+
 #include <libusb-1.0/libusb.h>
 
 
@@ -10,9 +13,19 @@ uint16_t product_id = 0;
 uint8_t reset = 0;
 uint8_t oneline = 0;
 uint8_t debug = 0;
+int infd = 0;
+int outfd = 1;
+uint8_t explicit_in = 0;
+
+libusb_device_handle *devh = NULL;
+uint8_t endpoint = 0;
 
 #define USBERR(msg, rc) { dprintf(2, "%s: %s\n", msg, libusb_strerror(rc)); }
-#define DEBUG(...) { if (debug) { dprintf(2, __VA_ARGS__); } }
+#define DEBUG(...) { if (debug >= 1) { dprintf(2, __VA_ARGS__); } }
+#define DEBUG2(...) { if (debug >= 2) { dprintf(2, __VA_ARGS__); } }
+#define DEBUG3(...) { if (debug >= 3) { dprintf(2, __VA_ARGS__); } }
+#define HEXBUF(msg, buf, n) { if (debug >= 3) { dprintf(2, "%s:", msg); for (uint8_t *__h = buf; __h < buf+n;++__h) { dprintf(2, " %02x", *__h); } dprintf(2, "\n"); } }
+
 
 uint32_t vidpid[] = {
   0x0c2e0b01,
@@ -21,23 +34,186 @@ uint32_t vidpid[] = {
 };
 
 
-int config(int argc, char **args) {
+struct tokenizer {
+  char tokbuf[1024];
+  char *tok;
+  uint8_t eot;
+  int (*cb)(const char *tok, uint8_t last);
+};
+
+
+void tok_init(struct tokenizer *t, int (*cb)(const char *tok, uint8_t last)) {
+  memset(t->tokbuf, 0, 1024);
+  t->tok = t->tokbuf;
+  t->eot = 0;
+  t->cb = cb;
+}
+
+int tok_read(struct tokenizer *t, char *buf, size_t n) {
+  char *start = buf;
+  char *end = start;
+  while (!t->eot) {
+    // non-final tokens: terminated by ;
+    end = strchr(start, ';');
+    if (end) {
+      if (end > start) {
+	for (char *c = start; c < end; ++c) {
+	  if (isprint(*c)) {
+	    *(t->tok++) = *c;
+	  }
+	}
+      }
+      *(t->tok) = 0;
+      if (t->cb(t->tokbuf, 0)) {
+	return 1;
+      }
+      t->tok = t->tokbuf;
+      *(t->tok) = 0;
+      start = end + 1;
+      continue;
+    }
+    // last token: terminated by .
+    end = strchr(start, '.');
+    if (end) {
+      t->eot = 1;
+      if (end > start) {
+	for (char *c = start; c < end; ++c) {
+	  if (isprint(*c)) {
+	    *(t->tok++) = *c;
+	  }
+	}
+      }
+      *(t->tok) = 0;
+      if (t->cb(t->tokbuf, 1)) {
+	return 1;
+      }
+      t->tok = t->tokbuf;
+      *(t->tok) = 0;
+      break;
+    }
+    // incomplete tokens continued in the next message
+    end = strchr(start, '?');
+    if (end) {
+      *end = 0;
+    }
+    for (char *c = start; *c != 0; ++c) {
+      if (isprint(*c)) {
+	*(t->tok++) = *c;
+      }
+    }
+    *(t->tok) = 0;
+    break;
+  }
+  return 0;
+}
+
+
+struct tokenizer in_tok;
+struct tokenizer out_tok;
+
+
+int print_token(const char *tok, uint8_t last) {
+  int rc;
+  if (oneline && !last) {
+    rc = dprintf(outfd, "%s;", tok);
+  } else {
+    rc = dprintf(outfd, "%s.\n", tok);
+  }
+  return rc < 0;
+}
+
+
+int send_token(const char *tok, uint8_t last) {
   uint8_t cmd[64] = { 0 };
-  char tokbuf[1024] = { 0 };
+  uint8_t *cmdptr = cmd + 5;
+  int rc;
+  memset(cmdptr, 0, 59);
+  for (uint8_t i = 0; i < strlen(tok); ++i) {
+    if (isprint(tok[i])) {
+      *(cmdptr++) = tok[i];
+    }
+  }
+  *cmdptr = '.';
+  cmd[0] = 0xfd;
+  cmd[1] = cmdptr - cmd - 1;
+  cmd[2] = 0x16;
+  cmd[3] = 0x4d;
+  cmd[4] = 0x0d;
+  HEXBUF(">", cmd, 64);
+  rc = libusb_control_transfer(devh, 0x21, 0x09, 0x02fd, 1, cmd, 64, 0);
+  if (rc < 0) {
+    USBERR("failed to send control message", rc);
+    return 1;
+  } else {
+    DEBUG2("> %s\n", cmd+5);
+  }
+  int tx;
+  tok_init(&out_tok, print_token);
+  // Repeat until a "." (EOT) is encountered in the response.
+  while (!out_tok.eot) {
+    rc = libusb_interrupt_transfer(devh, endpoint, cmd, 64, &tx, 1000);
+    if (rc) {
+      USBERR("failed to receive response from device", rc);
+      return 1;
+    }
+    HEXBUF("<", cmd, tx);
+    // skip first 5 bytes (report id, length, 3*AIMID)
+    DEBUG2("< %s\n", cmd+5);
+    if (tok_read(&out_tok, (char *) cmd+5, tx-5)) {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+
+int config(int argc, char **args) {
+  // If commands are provided on the CLI, execute only those
+  if (argc > 0) {
+    for (int i = 0; i < argc; ++i) {
+      if (send_token(args[i], i >= argc-1)) {
+	return 1;
+      }
+    }
+    return 0;
+  }
+  // If input is a tty, dump config
+  // Can be overwritten with "-i -" on the cli
+  if (isatty(infd) && !explicit_in) {
+    return send_token("?", 1);
+  }
+  // Otherwhise parse tokens from stdin
+  char buf[65];
+  ssize_t n = 1;
+  tok_init(&in_tok, send_token);
+  while (n) {
+    n = read(infd, buf, 64);
+    if (n < 0) {
+      perror("failed to read from input file");
+      return 1;
+    }
+    buf[n] = 0;
+    if (tok_read(&in_tok, buf, n)) {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+
+int usb(int argc, char **args) {
   libusb_context *ctx = NULL;
   libusb_device *dev = NULL;
-  libusb_device_handle *devh = NULL;
   struct libusb_device_descriptor devd = { 0 };
   struct libusb_config_descriptor *devc = NULL;
   const struct libusb_interface *devi = NULL;
   const struct libusb_interface_descriptor *devid = NULL;
   const struct libusb_endpoint_descriptor *deved = NULL;
   char devdesc[256] = { 0 };
-  int rc = 0;
+  int rc = 0, fail = 0;
 
   uint8_t ints[32] = { 0 };
   uint8_t inti = 0;
-  uint8_t endpoint = 0;
 
   //
   // Find and open the device
@@ -45,14 +221,16 @@ int config(int argc, char **args) {
   rc = libusb_init(&ctx);
   if (!ctx) {
     USBERR("failed to initialize libusb", rc);
-    return 1;
+    fail = 1;
+    goto fail;
   }
 
   if (vendor_id || product_id) {
     devh = libusb_open_device_with_vid_pid(ctx, vendor_id, product_id);
     if (!devh) {
       dprintf(2, "device %04x:%04x not found\n", vendor_id, product_id);
-      return 1;
+      fail = 1;
+      goto fail;
     }
   } else {
     devh = NULL;
@@ -61,7 +239,8 @@ int config(int argc, char **args) {
     }
     if (!devh) {
       dprintf(2, "default devices not found, please provide vendor and product id\n");
-      return 1;
+      fail = 1;
+      goto fail;
     }
   }
 
@@ -70,8 +249,34 @@ int config(int argc, char **args) {
   rc = libusb_get_device_descriptor(dev, &devd);
   if (rc) {
     USBERR("failed to get device descriptor", rc);
-    return 1;
+    fail = 1;
+    goto fail;
   }
+
+  // Print device info
+  rc = libusb_get_string_descriptor_ascii(devh, devd.iManufacturer, (uint8_t *) devdesc, 256);
+  if (rc < 0) {
+    USBERR("failed to get manufacturer string descriptor", rc);
+    fail = 1;
+    goto fail;
+  }
+  DEBUG("Manufacturer: %s\n", devdesc);
+  rc = libusb_get_string_descriptor_ascii(devh, devd.iProduct, (uint8_t *) devdesc, 256);
+  if (rc < 0) {
+    USBERR("failed to get product string descriptor", rc);
+    fail = 1;
+    goto fail;
+  }
+  DEBUG("Product: %s\n", devdesc);
+  rc = libusb_get_string_descriptor_ascii(devh, devd.iSerialNumber, (uint8_t *) devdesc, 256);
+  if (rc < 0) {
+    USBERR("failed to get serial number string descriptor", rc);
+    fail = 1;
+    goto fail;
+  }
+  DEBUG("Serial Number: %s\n", devdesc);
+
+  // Iterate all configurations, interfaces and endpoints to find the REM/EZConfig endpoint
   for (uint8_t c = 0; c < devd.bNumConfigurations; ++c) {
     libusb_free_config_descriptor(devc);
     rc = libusb_get_config_descriptor(dev, c, &devc);
@@ -84,9 +289,9 @@ int config(int argc, char **args) {
       USBERR("failed to get config string descriptor", rc);
       continue;
     }
-    DEBUG("- configuration %d: %s\n", c, devdesc);
+    DEBUG2("- configuration %d: %s\n", c, devdesc);
     for (uint8_t i = 0; i < devc->bNumInterfaces; ++i) {
-      DEBUG("  - interface %d\n", i);
+      DEBUG2("  - interface %d\n", i);
       devi = &(devc->interface[i]);
       for (uint8_t a = 0; a < devi->num_altsetting; ++a) {
 	devid = &(devi->altsetting[a]);
@@ -95,13 +300,13 @@ int config(int argc, char **args) {
 	  USBERR("failed to get interface string descriptor", rc);
 	  continue;
 	}
-	DEBUG("    - altsetting %d: interface=%d, desc=%s class=%d subclass=%d protocol=%d\n",
-		devid->bAlternateSetting, devid->bInterfaceNumber, devdesc,
-		devid->bInterfaceClass, devid->bInterfaceSubClass, devid->bInterfaceProtocol);
+	DEBUG2("    - altsetting %d: interface=%d, desc=%s class=%d subclass=%d protocol=%d\n",
+	      devid->bAlternateSetting, devid->bInterfaceNumber, devdesc,
+	      devid->bInterfaceClass, devid->bInterfaceSubClass, devid->bInterfaceProtocol);
 	for (uint8_t e = 0; e < devid->bNumEndpoints; ++e) {
 	  deved = &(devid->endpoint[e]);
 	  char type = "csbi"[deved->bmAttributes & 0b00000011];
-	  DEBUG("      - endpoint %x: t=%c\n", deved->bEndpointAddress, type);
+	  DEBUG2("      - endpoint %x: t=%c\n", deved->bEndpointAddress, type);
 	  // build a list of interfaces so that we can claim all of them
 	  ints[inti++] = devid->bInterfaceNumber;
 	  // endpoint selection:
@@ -116,7 +321,7 @@ int config(int argc, char **args) {
     }
   }
 
-  DEBUG("chose endpoint %x\n", endpoint);
+  DEBUG2("chose endpoint %x\n", endpoint);
 
   //
   // Disconnect usbhid driver from both device interfaces
@@ -128,13 +333,15 @@ int config(int argc, char **args) {
       rc = libusb_kernel_driver_active(devh, ints[i]);
       if (rc < 0) {
 	USBERR("failed to query kernel driver state", rc);
-	return 1;
+	fail = 1;
+	goto fail;
       }
       if (rc > 0) {
 	rc = libusb_detach_kernel_driver(devh, ints[i]);
 	if (rc) {
 	  USBERR("failed to detach kernel driver", rc);
-	  return 1;
+	  fail = 1;
+	  goto fail;
 	}
       }
     }
@@ -144,102 +351,40 @@ int config(int argc, char **args) {
     rc = libusb_claim_interface(devh, ints[i]);
     if (rc) {
       USBERR("failed to claim interface", rc);
-      return 1;
+      fail = 1;
+      goto fail;
     }
   }
 
   //
   // Prepare and send a message on the control channel for each config argument
   //
-  for (int i = 0; i < argc; ++i) {
-    memset(cmd+5, 0, 59);
-    cmd[0] = 0xfd;
-    cmd[1] = strlen(args[i])+3;
-    cmd[2] = 0x16;
-    cmd[3] = 0x4d;
-    cmd[4] = 0x0d;
-    memcpy(cmd+5, args[i], strlen(args[i]));
-    rc = libusb_control_transfer(devh, 0x21, 0x09, 0x02fd, 1, cmd, 64, 0);
-    if (rc < 0) {
-      USBERR("failed to send control message", rc);
-    } else {
-      DEBUG("> %s\n", args[i]);
-    }
-    int tx;
-    tokbuf[64] = 0;
-    char *start, *end, *tok = tokbuf;
-    uint8_t eot = 0;
-    // Repeat until a "." (EOT) is encountered in the response.
-    while (!eot) {
-      rc = libusb_interrupt_transfer(devh, endpoint, cmd, 64, &tx, 1000);
-      if (rc) {
-	USBERR("failed to receive response from device", rc);
-	break;
-      }
-      // strip 2-byte header and AIMID
-      start = (char *) cmd+5;
-      DEBUG("< %s\n", start);
-      while (1) {
-	// non-final tokens: terminated by ;
-	end = strchr(start, ';');
-	if (end) {
-	  if (end > start) {
-	    memcpy(tok, start, end-start-1);
-	    tok += end-start-1;
-	  }
-	  *tok = 0;
-	  if (oneline) {
-	    printf("%s;", tokbuf);
-	  } else {
-	    printf("%s.\n", tokbuf);
-	  }
-	  tok = tokbuf;
-	  *tok = 0;
-	  start = end + 1;
-	  continue;
-	}
-	// last token: terminated by .
-	end = strchr(start, '.');
-	if (end) {
-	  eot = 1;
-	  if (end > start) {
-	    memcpy(tok, start, end-start-1);
-	    tok += end-start-1;
-	  }
-	  *tok = 0;
-	  printf("%s.\n", tokbuf);
-	  tok = tokbuf;
-	  *tok = 0;
-	  break;
-	}
-	// incomplete tokens continued in the next message
-	end = strchr(start, '?');
-	if (end) {
-	  *end = 0;
-	}
-	strcpy(tok, start);
-	tok += strlen(start);
-	break;
-      }
-    }
+  rc = config(argc, args);
+  if (rc) {
+    fail = 1;
+    goto fail;
   }
 
   //
   // Cleanup
   //
-  for (uint8_t i = 0; i < inti; ++i) {
-    rc = libusb_release_interface(devh, ints[i]);
-    if (rc) {
-      USBERR("failed to release interface", rc);
-      return 1;
+ fail:
+  if (devh) {
+    for (uint8_t i = 0; i < inti; ++i) {
+      rc = libusb_release_interface(devh, ints[i]);
+      if (rc) {
+	USBERR("failed to release interface", rc);
+      }
     }
+    if (reset) {
+      libusb_reset_device(devh);
+    }
+    libusb_close(devh);
   }
-  if (reset) {
-    libusb_reset_device(devh);
+  if (ctx) {
+    libusb_exit(ctx);
   }
-  libusb_close(devh);
-  libusb_exit(ctx);
-  return 0;
+  return fail;
 }
 
 
@@ -247,7 +392,7 @@ int main(int argc, char **argv) {
   int opt;
   char *end;
   long parsed;
-  while ((opt = getopt(argc, argv, "v:p:ord")) != -1) {
+  while ((opt = getopt(argc, argv, "v:p:1rdi:o:")) != -1) {
     switch (opt) {
     case 'v':
       end = optarg;
@@ -278,21 +423,46 @@ int main(int argc, char **argv) {
     case 'r':
       reset = 1;
       break;
-    case 'o':
+    case '1':
       oneline = 1;
       break;
     case 'd':
-      debug = 1;
+      ++debug;
+      break;
+    case 'i':
+      explicit_in = 1;
+      if (!strcmp("-", optarg)) {
+	infd = 0;
+      } else {
+	infd = open(optarg, O_CLOEXEC|O_RDONLY);
+	if (infd < 0) {
+	  perror("failed to open input file");
+	  exit(1);
+	}
+      }
+      break;
+    case 'o':
+      if (!strcmp("-", optarg)) {
+	outfd = 1;
+      } else {
+	outfd = open(optarg, O_CLOEXEC|O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
+	if (outfd < 0) {
+	  perror("failed to open output file");
+	  exit(1);
+	}
+      }
       break;
     default:
-      printf("usage: %s [-v vendor] [-p product] [-o] [-r] [-d] command1 [command2 [... commandN]]\n", argv[0]);
+      printf("usage: %s [-v vendor] [-p product] [-1] [-r] [-d] [-i infile] [-o outfile] [command1 [... commandN]]\n", argv[0]);
       puts("  -v vendor\tUSB vendor ID of the barcode scanner");
       puts("  -p product\tUSB product ID of the barcode scanner");
-      puts("  -o\t\tPrint response on one line, rather than one token per line");
+      puts("  -1\t\tPrint response on one line, rather than one token per line");
       puts("  -r\t\tReset device after configuration");
       puts("  -d\t\tDebug mode (more verbose output)");
+      puts("  -i infile\tRead input from infile instead of stdin");
+      puts("  -o outfile\tWrite output to outfile instead of stdout");
       return 1;
     }
   }
-  return config(argc-optind, argv+optind);
+  return usb(argc-optind, argv+optind);
 }