diff --git a/sys/include/ps.h b/sys/include/ps.h
index 2b755dc184..cc63a3d015 100644
--- a/sys/include/ps.h
+++ b/sys/include/ps.h
@@ -9,6 +9,6 @@
 #define __PS_H
 
 void thread_print_all(void);
-void _ps_handler(char *);
+void _ps_handler(int argc, char **argv);
 
 #endif /* __PS_H */
diff --git a/sys/include/shell.h b/sys/include/shell.h
index b3776b98aa..ff346f704b 100644
--- a/sys/include/shell.h
+++ b/sys/include/shell.h
@@ -22,10 +22,12 @@
 #define __SHELL_H
 #include <stdint.h>
 
+typedef void (*shell_command_handler_t)(int argc, char **argv);
+
 typedef struct shell_command_t {
     char *name;
     char *desc;
-    void (*handler)(char *);
+    shell_command_handler_t handler;
 } shell_command_t;
 
 typedef struct shell_t {
diff --git a/sys/shell/commands/sc_cc1100.c b/sys/shell/commands/sc_cc1100.c
index cca1a581b3..041ed52a9d 100644
--- a/sys/shell/commands/sc_cc1100.c
+++ b/sys/shell/commands/sc_cc1100.c
@@ -23,13 +23,11 @@
 #include "cc110x.h"
 
 
-void _cc110x_get_set_address_handler(char *addr)
+void _cc110x_get_set_address_handler(int argc, char **argv)
 {
-    int16_t a;
+    if (argc > 1) {
+        int16_t a = atoi(argv[1]);
 
-    a = atoi(addr + 5);
-
-    if (strlen(addr) > 5) {
         printf("[cc110x] Setting address %i ... ", a);
         cc1100_set_address((radio_address_t)a);
 
@@ -45,13 +43,11 @@ void _cc110x_get_set_address_handler(char *addr)
     }
 }
 
-void _cc110x_get_set_channel_handler(char *addr)
+void _cc110x_get_set_channel_handler(int argc, char **argv)
 {
-    int16_t a;
+    if (argc > 1) {
+        int16_t a = atoi(argv[1]);
 
-    a = atoi(addr + 5);
-
-    if (strlen(addr) > 5) {
         printf("[cc110x] Setting channel %i...", a);
         cc1100_set_channel(a);
 
diff --git a/sys/shell/commands/sc_disk.c b/sys/shell/commands/sc_disk.c
index cebe67f85b..66fc8b02ae 100644
--- a/sys/shell/commands/sc_disk.c
+++ b/sys/shell/commands/sc_disk.c
@@ -44,10 +44,12 @@ static inline uint8_t sector_read(unsigned char *read_buf, unsigned long sector,
     return 0;
 }
 
-void _get_sectorsize(char *unused)
+void _get_sectorsize(int argc, char **argv)
 {
-    unsigned short ssize;
+    (void) argc;
+    (void) argv;
 
+    unsigned short ssize;
     if (MCI_ioctl(GET_SECTOR_SIZE, &ssize) == RES_OK) {
         printf("[disk] sector size is %u\n", ssize);
     }
@@ -56,10 +58,12 @@ void _get_sectorsize(char *unused)
     }
 }
 
-void _get_blocksize(char *unused)
+void _get_blocksize(int argc, char **argv)
 {
-    unsigned long bsize;
+    (void) argc;
+    (void) argv;
 
+    unsigned long bsize;
     if (MCI_ioctl(GET_BLOCK_SIZE, &bsize) == RES_OK) {
         printf("[disk] block size is %lu\n", bsize);
     }
@@ -68,10 +72,12 @@ void _get_blocksize(char *unused)
     }
 }
 
-void _get_sectorcount(char *unused)
+void _get_sectorcount(int argc, char **argv)
 {
-    unsigned long scount;
+    (void) argc;
+    (void) argv;
 
+    unsigned long scount;
     if (MCI_ioctl(GET_SECTOR_COUNT, &scount) == RES_OK) {
         printf("[disk] sector count is %lu\n", scount);
     }
@@ -80,14 +86,13 @@ void _get_sectorcount(char *unused)
     }
 }
 
-void _read_sector(char *sector)
+void _read_sector(int argc, char **argv)
 {
     unsigned long sectornr, scount;
     unsigned short ssize;
 
-    if (strlen(sector) > strlen(DISK_READ_SECTOR_CMD) + 1) {
-
-        sectornr = atol(sector + strlen(DISK_READ_SECTOR_CMD) + 1);
+    if (argc == 2) {
+        sectornr = atol(argv[1]);
 
         if ((MCI_ioctl(GET_SECTOR_COUNT, &scount) == RES_OK) && (MCI_ioctl(GET_SECTOR_SIZE, &ssize) == RES_OK)) {
             unsigned char read_buf[ssize];
@@ -100,65 +105,57 @@ void _read_sector(char *sector)
         printf("[disk] Error while reading sector %lu\n", sectornr);
     }
     else {
-        printf("[disk] Usage:\n%s <SECTOR>\n", DISK_READ_SECTOR_CMD);
+        printf("[disk] Usage:\n%s <SECTOR>\n", argv[0]);
         return;
     }
 }
 
-void _read_bytes(char *bytes)
+void _read_bytes(int argc, char **argv)
 {
     unsigned long sector = 1, scount, offset;
     unsigned short ssize, length;
-    char *tok;
 
-    /* tokenize user input */
-    tok = strtok(bytes + strlen(DISK_READ_BYTES_CMD) + 1, " ");
+    if (argc != 3) {
+        printf("[disk] Usage:\n%s <OFFSET> <LENGTH>\n", argv[0]);
+        return;
+    }
 
-    if (tok) {
-        offset = atol(tok);
-        tok = strtok(NULL, " ");
+    offset = atol(argv[1]);
+    length = atoi(argv[2]);
 
-        if (tok) {
-            length = atoi(tok);
+    /* get card info */
+    if ((MCI_ioctl(GET_SECTOR_COUNT, &scount) == RES_OK) && (MCI_ioctl(GET_SECTOR_SIZE, &ssize) == RES_OK)) {
+        /* calculate sector and offset position */
+        sector = (offset / ssize) + 1;
+        offset = (offset % ssize);
+        /* preapre buffer (size must be a multiple of sector size) */
+        unsigned char read_buf[((length / ssize) + 1) * 512];
 
-            if (length) {
-                /* get card info */
-                if ((MCI_ioctl(GET_SECTOR_COUNT, &scount) == RES_OK) && (MCI_ioctl(GET_SECTOR_SIZE, &ssize) == RES_OK)) {
-                    /* calculate sector and offset position */
-                    sector = (offset / ssize) + 1;
-                    offset = (offset % ssize);
-                    /* preapre buffer (size must be a multiple of sector size) */
-                    unsigned char read_buf[((length / ssize) + 1) * 512];
+        /* read from several sectors */
+        if (length > (ssize - offset)) {
+            /* buffer offset */
+            unsigned long j = 0;
+            /* chunk from current sector */
+            unsigned short tmp = ssize - offset;
 
-                    /* read from several sectors */
-                    if (length > (ssize - offset)) {
-                        /* buffer offset */
-                        unsigned long j = 0;
-                        /* chunk from current sector */
-                        unsigned short tmp = ssize - offset;
+            while (length) {
+                sector_read(read_buf + j, sector++, tmp, offset);
+                /* decrease length  and recalculate chunk */
+                length -= tmp;
+                tmp = (length >= ssize) ? ssize : length;
+            }
 
-                        while (length) {
-                            sector_read(read_buf + j, sector++, tmp, offset);
-                            /* decrease length  and recalculate chunk */
-                            length -= tmp;
-                            tmp = (length >= ssize) ? ssize : length;
-                        }
-
-                        return;
-                    } /* length > (ssize - offset) */
-                    /* read only one sector */
-                    else {
-                        if (sector_read(read_buf, sector, length, offset)) {
-                            return;
-                        }
-                    } /* length < (ssize - offset) */
-                } /* ioctl */
-
-                printf("[disk] Error while reading sector %lu\n", sector);
+            return;
+        } /* length > (ssize - offset) */
+        /* read only one sector */
+        else {
+            if (sector_read(read_buf, sector, length, offset)) {
                 return;
-            } /* length */
-        } /* strtok #2 */
-    } /* strtok #1 */
+            }
+        } /* length < (ssize - offset) */
+    } /* ioctl */
+
+    printf("[disk] Error while reading sector %lu\n", sector);
+    return;
 
-    printf("[disk] Usage:\n%s <OFFSET> <LENGTH>\n", DISK_READ_BYTES_CMD);
 }
diff --git a/sys/shell/commands/sc_heap.c b/sys/shell/commands/sc_heap.c
index 233d862a80..ee6156159e 100644
--- a/sys/shell/commands/sc_heap.c
+++ b/sys/shell/commands/sc_heap.c
@@ -20,8 +20,10 @@
 
 extern void heap_stats(void);
 
-void _heap_handler(char *unused)
+void _heap_handler(int argc, char **argv)
 {
-    (void) unused;
+    (void) argc;
+    (void) argv;
+
     heap_stats();
 }
diff --git a/sys/shell/commands/sc_id.c b/sys/shell/commands/sc_id.c
index 8ed7aa627a..36389f192d 100644
--- a/sys/shell/commands/sc_id.c
+++ b/sys/shell/commands/sc_id.c
@@ -20,16 +20,13 @@
 #include <stdlib.h>
 #include "config.h"
 
-void _id_handler(char *id)
+void _id_handler(int argc, char **argv)
 {
-    long newid;
-
-    newid = atoi(id + 3);
-
-    if (strlen(id) < 3) {
+    if (argc < 2) {
         printf("Current id: %u\n", sysconfig.id);
     }
     else {
+        long newid = atoi(argv[1]);
         printf("Setting new id %lu\n", newid);
         sysconfig.id = newid;
 
diff --git a/sys/shell/commands/sc_ltc4150.c b/sys/shell/commands/sc_ltc4150.c
index 7acf7f25ce..0f48d0c2ec 100644
--- a/sys/shell/commands/sc_ltc4150.c
+++ b/sys/shell/commands/sc_ltc4150.c
@@ -18,16 +18,19 @@
 #include <stdio.h>
 #include "ltc4150.h"
 
-void _get_current_handler(char *unused)
+void _get_current_handler(int argc, char **argv)
 {
-    (void) unused;
+    (void) argc;
+    (void) argv;
 
-    printf("Power usage: %.4f mA (%.4f mA avg/ %.4f mAh total / %i usec)\n", ltc4150_get_current_mA(), ltc4150_get_avg_mA(), ltc4150_get_total_mAh(), ltc4150_get_interval());
+    printf("Power usage: %.4f mA (%.4f mA avg/ %.4f mAh total / %i usec)\n",
+           ltc4150_get_current_mA(), ltc4150_get_avg_mA(), ltc4150_get_total_mAh(), ltc4150_get_interval());
 }
 
-void _reset_current_handler(char *unused)
+void _reset_current_handler(int argc, char **argv)
 {
-    (void) unused;
+    (void) argc;
+    (void) argv;
 
     ltc4150_start();
 }
diff --git a/sys/shell/commands/sc_mersenne.c b/sys/shell/commands/sc_mersenne.c
index b6440e9b3f..c21a9a7665 100644
--- a/sys/shell/commands/sc_mersenne.c
+++ b/sys/shell/commands/sc_mersenne.c
@@ -23,27 +23,26 @@
 #include "hwtimer.h"
 #include "random.h"
 
-void _mersenne_init(char *str)
+void _mersenne_init(int argc, char **argv)
 {
     int initval;
-    char *toc_str = strtok(str, " ");
 
-    toc_str = strtok(NULL, " ");
-    if (!toc_str) {
+    if (argc == 1) {
         initval = hwtimer_now();
-        printf("PRNG inizialized to current time: %d\n", initval);
+        printf("PRNG initialized to current time: %d\n", initval);
     }
     else {
-        initval = atoi(toc_str);
-        printf("PRNG inizialized given value: %d\n", initval);
+        initval = atoi(argv[1]);
+        printf("PRNG initialized given value: %d\n", initval);
     }
 
     genrand_init(initval);
 }
 
-void _mersenne_get(char *str)
+void _mersenne_get(int argc, char **argv)
 {
-    (void) str;
+    (void) argc;
+    (void) argv;
 
     printf("%" PRIu32 "\n", genrand_uint32());
 }
diff --git a/sys/shell/commands/sc_ps.c b/sys/shell/commands/sc_ps.c
index f076b78f69..226d49ea14 100644
--- a/sys/shell/commands/sc_ps.c
+++ b/sys/shell/commands/sc_ps.c
@@ -17,9 +17,10 @@
 
 #include "ps.h"
 
-void _ps_handler(char *unused)
+void _ps_handler(int argc, char **argv)
 {
-    (void) unused;
+    (void) argc;
+    (void) argv;
 
     thread_print_all();
 }
diff --git a/sys/shell/commands/sc_rtc.c b/sys/shell/commands/sc_rtc.c
index 56db40fbc6..7b30ee3348 100644
--- a/sys/shell/commands/sc_rtc.c
+++ b/sys/shell/commands/sc_rtc.c
@@ -22,7 +22,7 @@
 #ifdef MODULE_RTC
 #include "rtc.h"
 
-void _gettime_handler(void)
+static void _gettime_handler(void)
 {
     struct tm now;
     rtc_get_localtime(&now);
@@ -30,19 +30,19 @@ void _gettime_handler(void)
     printf("%s", asctime(&now));
 }
 
-void _settime_handler(char *c)
+static void _settime_handler(char *c)
 {
     struct tm now;
     int res;
     uint16_t month, epoch_year;
 
-    res = sscanf(c, "date %hu-%hu-%u %u:%u:%u",
+    res = sscanf(c, "%hu-%hu-%u %u:%u:%u",
                  &epoch_year,
                  &month,
-                 (unsigned int *) & (now.tm_mday),
-                 (unsigned int *) & (now.tm_hour),
-                 (unsigned int *) & (now.tm_min),
-                 (unsigned int *) & (now.tm_sec));
+                 (unsigned int *) &(now.tm_mday),
+                 (unsigned int *) &(now.tm_hour),
+                 (unsigned int *) &(now.tm_min),
+                 (unsigned int *) &(now.tm_sec));
 
     if (res < 6) {
         printf("Usage: date YYYY-MM-DD hh:mm:ss\n");
@@ -57,13 +57,13 @@ void _settime_handler(char *c)
     rtc_set_localtime(&now);
 }
 
-void _date_handler(char *c)
+void _date_handler(int argc, char **argv)
 {
-    if (strlen(c) == 4) {
+    if (argc == 1) {
         _gettime_handler();
     }
     else {
-        _settime_handler(c);
+        _settime_handler(argv[1]);
     }
 }
 
diff --git a/sys/shell/commands/sc_sht11.c b/sys/shell/commands/sc_sht11.c
index ce088ec562..67620fd7d5 100644
--- a/sys/shell/commands/sc_sht11.c
+++ b/sys/shell/commands/sc_sht11.c
@@ -25,8 +25,11 @@
 
 extern float sht11_temperature_offset;
 
-void _get_humidity_handler(char *unused)
+void _get_humidity_handler(int argc, char **argv)
 {
+    (void) argc;
+    (void) argv;
+
     uint8_t success;
     sht11_val_t sht11_val;
     success = sht11_read_sensor(&sht11_val, HUMIDITY | TEMPERATURE);
@@ -39,8 +42,11 @@ void _get_humidity_handler(char *unused)
                (double) sht11_val.relhum, (double) sht11_val.relhum_temp);
     }
 }
-void _get_temperature_handler(char *unused)
+void _get_temperature_handler(int argc, char **argv)
 {
+    (void) argc;
+    (void) argv;
+
     uint8_t success;
     sht11_val_t sht11_val;
     success = sht11_read_sensor(&sht11_val, TEMPERATURE);
@@ -52,8 +58,11 @@ void _get_temperature_handler(char *unused)
         printf("Temperature: %-6.2f°C\n", (double) sht11_val.temperature);
     }
 }
-void _get_weather_handler(char *unused)
+void _get_weather_handler(int argc, char **argv)
 {
+    (void) argc;
+    (void) argv;
+
     uint8_t success;
     sht11_val_t sht11_val;
     success = sht11_read_sensor(&sht11_val, HUMIDITY | TEMPERATURE);
@@ -68,13 +77,13 @@ void _get_weather_handler(char *unused)
     }
 }
 
-void _set_offset_handler(char *offset)
+void _set_offset_handler(int argc, char **argv)
 {
-    if (strlen(offset) == 6) {
-        puts("Usage: offset <OFFSET>");
+    if (argc != 2) {
+        printf("Usage: %s <OFFSET>\n", argv[0]);
     }
     else {
-        sht11_temperature_offset = atoi(offset + 7);
+        sht11_temperature_offset = atoi(argv[1]);
         printf("Temperature offset set to %f\n", (double) sht11_temperature_offset);
     }
 }
diff --git a/sys/shell/commands/sc_sys.c b/sys/shell/commands/sc_sys.c
index 54ecaec49e..5bb381d3f4 100644
--- a/sys/shell/commands/sc_sys.c
+++ b/sys/shell/commands/sc_sys.c
@@ -17,8 +17,10 @@
 
 #include "kernel.h"
 
-void _reboot_handler(char *unused)
+void _reboot_handler(int argc, char **argv)
 {
-    (void) unused;
+    (void) argc;
+    (void) argv;
+
     reboot();
 }
diff --git a/sys/shell/commands/sc_transceiver.c b/sys/shell/commands/sc_transceiver.c
index 6ec76f9fea..6d5ec8c5e6 100644
--- a/sys/shell/commands/sc_transceiver.c
+++ b/sys/shell/commands/sc_transceiver.c
@@ -52,7 +52,7 @@
 
 
 /* checked for type safety */
-void _transceiver_get_set_address_handler(char *addr)
+void _transceiver_get_set_address_handler(int argc, char **argv)
 {
     msg_t mesg;
     transceiver_command_t tcmd;
@@ -67,8 +67,8 @@ void _transceiver_get_set_address_handler(char *addr)
     tcmd.data = &a;
     mesg.content.ptr = (char *) &tcmd;
 
-    if (strlen(addr) > 5) {
-        a = atoi(addr + 5);
+    if (argc > 1) {
+        a = atoi(argv[1]);
         printf("[transceiver] trying to set address %" PRIu16 "\n", a);
         mesg.type = SET_ADDRESS;
     }
@@ -81,7 +81,7 @@ void _transceiver_get_set_address_handler(char *addr)
 }
 
 /* checked for type safety */
-void _transceiver_get_set_channel_handler(char *chan)
+void _transceiver_get_set_channel_handler(int argc, char **argv)
 {
     msg_t mesg;
     transceiver_command_t tcmd;
@@ -96,8 +96,8 @@ void _transceiver_get_set_channel_handler(char *chan)
     tcmd.data = &c;
     mesg.content.ptr = (char *) &tcmd;
 
-    if (strlen(chan) > 5) {
-        c = atoi(chan + 5);
+    if (argc > 1) {
+        c = atoi(argv[1]);
         printf("[transceiver] Trying to set channel %" PRIi32 "\n", c);
         mesg.type = SET_CHANNEL;
     }
@@ -114,93 +114,85 @@ void _transceiver_get_set_channel_handler(char *chan)
     }
 }
 
-void _transceiver_send_handler(char *pkt)
+void _transceiver_send_handler(int argc, char **argv)
 {
-    msg_t mesg;
-    transceiver_command_t tcmd;
-    char text_msg[TEXT_SIZE];
+    if (transceiver_pid < 0) {
+        puts("Transceiver not initialized");
+        return;
+    }
+    if (argc != 3) {
+        printf("Usage:\t%s <ADDR> <MSG>\n", argv[0]);
+        return;
+    }
 
     radio_packet_t p;
-    int8_t response;
-    radio_address_t addr;
-    char *tok;
-
-    if (transceiver_pid < 0) {
-        puts("Transceiver not initialized");
-        return;
-    }
 
+    transceiver_command_t tcmd;
     tcmd.transceivers = _TC_TYPE;
     tcmd.data = &p;
 
-    tok = strtok(pkt + 7, " ");
+    char text_msg[TEXT_SIZE];
+    memset(text_msg, 0, TEXT_SIZE);
+    strcpy(text_msg, argv[2]);
 
-    if (tok) {
-        addr = atoi(tok);
-        tok = strtok(NULL, " ");
+    p.data = (uint8_t *) text_msg;
+    p.length = strlen(text_msg) + 1;
+    p.dst = atoi(argv[1]);
 
-        if (tok) {
-            memset(text_msg, 0, TEXT_SIZE);
-            memcpy(text_msg, tok, strlen(tok));
-            p.data = (uint8_t *) text_msg;
-            p.length = strlen(text_msg) + 1;
-            p.dst = addr;
-            mesg.type = SND_PKT;
-            mesg.content.ptr = (char *)&tcmd;
-            printf("[transceiver] Sending packet of length %" PRIu16 " to %" PRIu16 ": %s\n", p.length, p.dst, (char*) p.data);
-            msg_send_receive(&mesg, &mesg, transceiver_pid);
-            response = mesg.content.value;
-            printf("[transceiver] Packet sent: %" PRIi8 "\n", response);
-            return;
-        }
-    }
-
-    puts("Usage:\ttxtsnd <ADDR> <MSG>");
-}
-
-/* checked for type safety */
-void _transceiver_monitor_handler(char *mode)
-{
     msg_t mesg;
-    transceiver_command_t tcmd;
-    uint8_t m;
-
-    if (transceiver_pid < 0) {
-        puts("Transceiver not initialized");
-        return;
-    }
-
-    tcmd.transceivers = _TC_TYPE;
-    tcmd.data = &m;
+    mesg.type = SND_PKT;
     mesg.content.ptr = (char *) &tcmd;
 
-    if (strlen(mode) > 8) {
-        m = atoi(mode + 8);
-        printf("Setting monitor mode: %" PRIu8 "\n", m);
-        mesg.type = SET_MONITOR;
-        msg_send(&mesg, transceiver_pid, 1);
-    }
-    else {
-        puts("Usage:\nmonitor <MODE>");
-    }
+    printf("[transceiver] Sending packet of length %" PRIu16 " to %" PRIu16 ": %s\n", p.length, p.dst, (char*) p.data);
+    msg_send_receive(&mesg, &mesg, transceiver_pid);
+    int8_t response = mesg.content.value;
+    printf("[transceiver] Packet sent: %" PRIi8 "\n", response);
 }
 
 /* checked for type safety */
-void _transceiver_get_set_pan_handler(char *pan) {
-    transceiver_command_t tcmd;
-    msg_t mesg;
-    int32_t p;
+void _transceiver_monitor_handler(int argc, char **argv)
+{
+    if (transceiver_pid < 0) {
+        puts("Transceiver not initialized");
+        return;
+    }
+    else if (argc != 2) {
+        printf("Usage:\n%s <MODE>\n", argv[0]);
+        return;
+    }
 
+    uint8_t m = atoi(argv[1]);
+    printf("Setting monitor mode: %" PRIu8 "\n", m);
+
+    transceiver_command_t tcmd;
+    tcmd.transceivers = _TC_TYPE;
+    tcmd.data = &m;
+
+    msg_t mesg;
+    mesg.content.ptr = (char *) &tcmd;
+    mesg.type = SET_MONITOR;
+
+    msg_send(&mesg, transceiver_pid, 1);
+}
+
+/* checked for type safety */
+void _transceiver_get_set_pan_handler(int argc, char **argv)
+{
     if (transceiver_pid < 0) {
         puts("Transceiver not initialized");
         return;
     }
 
+    int32_t p;
+
+    transceiver_command_t tcmd;
     tcmd.transceivers = _TC_TYPE;
     tcmd.data = &p;
+
+    msg_t mesg;
     mesg.content.ptr = (char*) &tcmd;
-    if (strlen(pan) > 4) {
-        p = atoi(pan+4);
+    if (argc > 1) {
+        p = atoi(argv[1]);
         printf("[transceiver] Trying to set pan %" PRIi32 "\n", p);
         mesg.type = SET_PAN;
     }
@@ -218,37 +210,37 @@ void _transceiver_get_set_pan_handler(char *pan) {
 
 /* checked for type safety */
 #ifdef DBG_IGNORE
-void _transceiver_set_ignore_handler(char *addr)
+void _transceiver_set_ignore_handler(int argc, char **argv)
 {
-    transceiver_command_t tcmd;
-    msg_t mesg;
-    radio_address_t a;
-    int16_t response;
 
     if (transceiver_pid < 0) {
         puts("Transceiver not initialized");
         return;
     }
+    else if (argc != 2) {
+        printf("Usage:\n%s <address>\n", argv[1]);
+    }
 
+    radio_address_t a;
+
+    transceiver_command_t tcmd;
     tcmd.transceivers = _TC_TYPE;
     tcmd.data = &a;
+
+    msg_t mesg;
     mesg.content.ptr = (char*) &tcmd;
 
-    if (strlen(addr) > 4) {
-        a = atoi(addr + 4);
-        printf("[transceiver] trying to add address %" PRIu16 " to the ignore list \n", a);
-        mesg.type = DBG_IGN;
-        msg_send_receive(&mesg, &mesg, transceiver_pid);
-        response = a;
-        if (response == -1) {
-            printf("Error: ignore list full\n");
-        }
-        else {
-            printf("Success (added at index %" PRIi16 ").\n", response);
-        }
+    a = atoi(addr + 4);
+    printf("[transceiver] trying to add address %" PRIu16 " to the ignore list \n", a);
+    mesg.type = DBG_IGN;
+    msg_send_receive(&mesg, &mesg, transceiver_pid);
+
+    int16_t response = a;
+    if (response == -1) {
+        printf("Error: ignore list full\n");
     }
     else {
-        puts("Usage:\nign <address>");
+        printf("Success (added at index %" PRIi16 ").\n", response);
     }
 }
 #endif
diff --git a/sys/shell/commands/shell_commands.c b/sys/shell/commands/shell_commands.c
index d9bf2c880f..8149785a79 100644
--- a/sys/shell/commands/shell_commands.c
+++ b/sys/shell/commands/shell_commands.c
@@ -23,34 +23,34 @@
 #include <stdlib.h>
 #include "shell_commands.h"
 
-extern void _reboot_handler(char *unused);
+extern void _reboot_handler(int argc, char **argv);
 
 #ifdef MODULE_CONFIG
-extern void _id_handler(char *id);
+extern void _id_handler(int argc, char **argv);
 #endif
 
 #ifdef MODULE_LPC_COMMON
-extern void _heap_handler(char *unused);
+extern void _heap_handler(int argc, char **argv);
 #endif
 
 #ifdef MODULE_PS
-extern void _ps_handler(char *unused);
+extern void _ps_handler(int argc, char **argv);
 #endif
 
 #ifdef MODULE_RTC
-extern void _date_handler(char *now);
+extern void _date_handler(int argc, char **argv);
 #endif
 
 #ifdef MODULE_SHT11
-extern void _get_temperature_handler(char *unused);
-extern void _get_humidity_handler(char *unused);
-extern void _get_weather_handler(char *unused);
-extern void _set_offset_handler(char *offset);
+extern void _get_temperature_handler(int argc, char **argv);
+extern void _get_humidity_handler(int argc, char **argv);
+extern void _get_weather_handler(int argc, char **argv);
+extern void _set_offset_handler(int argc, char **argv);
 #endif
 
 #ifdef MODULE_LTC4150
-extern void _get_current_handler(char *unused);
-extern void _reset_current_handler(char *unused);
+extern void _get_current_handler(int argc, char **argv);
+extern void _reset_current_handler(int argc, char **argv);
 #endif
 
 
@@ -70,43 +70,43 @@ extern void _reset_current_handler(char *unused);
 #endif
 #else /* WITHOUT MODULE_TRANSCEIVER */
 #ifdef MODULE_CC110X
-extern void _cc110x_get_set_address_handler(char *addr);
-extern void _cc110x_get_set_channel_handler(char *addr);
+extern void _cc110x_get_set_address_handler(int argc, char **argv);
+extern void _cc110x_get_set_channel_handler(int argc, char **argv);
 #endif
 #endif
 
 #ifdef MODULE_TRANSCEIVER
 #ifdef _TC_ADDR
-extern void _transceiver_get_set_address_handler(char *addr);
+extern void _transceiver_get_set_address_handler(int argc, char **argv);
 #endif
 #ifdef _TC_CHAN
-extern void _transceiver_get_set_channel_handler(char *chan);
+extern void _transceiver_get_set_channel_handler(int argc, char **argv);
 #endif
 #ifdef _TC_SEND
-extern void _transceiver_send_handler(char *pkt);
+extern void _transceiver_send_handler(int argc, char **argv);
 #endif
 #ifdef _TC_MON
-extern void _transceiver_monitor_handler(char *mode);
+extern void _transceiver_monitor_handler(int argc, char **argv);
 #endif
 #ifdef _TC_PAN
-extern void _transceiver_get_set_pan_handler(char *chan);
+extern void _transceiver_get_set_pan_handler(int argc, char **argv);
 #endif
 #ifdef _TC_IGN
-extern void _transceiver_set_ignore_handler(char *addr);
+extern void _transceiver_set_ignore_handler(int argc, char **argv);
 #endif
 #endif
 
 #ifdef MODULE_MCI
-extern void _get_sectorsize(char *unused);
-extern void _get_blocksize(char *unused);
-extern void _get_sectorcount(char *unused);
-extern void _read_sector(char *sector);
-extern void _read_bytes(char *bytes);
+extern void _get_sectorsize(int argc, char **argv);
+extern void _get_blocksize(int argc, char **argv);
+extern void _get_sectorcount(int argc, char **argv);
+extern void _read_sector(int argc, char **argv);
+extern void _read_bytes(int argc, char **argv);
 #endif
 
 #ifdef MODULE_RANDOM
-extern void _mersenne_init(char *str);
-extern void _mersenne_get(char *str);
+extern void _mersenne_init(int argc, char **argv);
+extern void _mersenne_get(int argc, char **argv);
 #endif
 
 const shell_command_t _shell_command_list[] = {
@@ -134,7 +134,6 @@ const shell_command_t _shell_command_list[] = {
     {"rstcur", "Resets coulomb counter.", _reset_current_handler},
 #endif
 
-
 #ifdef MODULE_TRANSCEIVER
 #ifdef _TC_ADDR
     {"addr", "Gets or sets the address for the transceiver", _transceiver_get_set_address_handler},
@@ -161,7 +160,6 @@ const shell_command_t _shell_command_list[] = {
 #endif
 #endif
 
-
 #ifdef MODULE_MCI
     {DISK_READ_SECTOR_CMD, "Reads the specified sector of inserted memory card", _read_sector},
     {DISK_READ_BYTES_CMD, "Reads the specified bytes from inserted memory card", _read_bytes},
@@ -173,5 +171,6 @@ const shell_command_t _shell_command_list[] = {
     { "mersenne_init", "initializes the PRNG", _mersenne_init },
     { "mersenne_get", "returns 32 bit of pseudo randomness", _mersenne_get },
 #endif
+
     {NULL, NULL, NULL}
 };
diff --git a/sys/shell/shell.c b/sys/shell/shell.c
index b72709f9bd..732a27223e 100644
--- a/sys/shell/shell.c
+++ b/sys/shell/shell.c
@@ -33,7 +33,7 @@
 #include "shell.h"
 #include "shell_commands.h"
 
-static void(*find_handler(const shell_command_t *command_list, char *command))(char *)
+static shell_command_handler_t find_handler(const shell_command_t *command_list, char *command)
 {
     const shell_command_t *command_lists[] = {
         command_list,
@@ -90,25 +90,64 @@ static void print_help(const shell_command_t *command_list)
 
 static void handle_input_line(shell_t *shell, char *line)
 {
-    char *saveptr;
-    char *command = strtok_r(line, " ", &saveptr);
-
-    void (*handler)(char *) = NULL;
-
-    if (command) {
-        handler = find_handler(shell->command_list, command);
-
-        if (handler != NULL) {
-            line[strlen(command)] = ' ';
-            handler(line);
+    /* first we need to calculate the number of arguments */
+    unsigned argc = 0;
+    char *pos;
+    for (pos = line; *pos; ++pos) {
+        if (*pos <= ' ') {
+            *pos = 0;
+            continue;
+        }
+        else if (*pos == '"') {
+            do {
+                ++pos;
+                if (!*pos) {
+                    puts("shell: incorrect quoting");
+                    return;
+                }
+            } while (*pos != '"');
         }
         else {
-            if (strcmp("help", command) == 0) {
-                print_help(shell->command_list);
-            }
-            else {
-                puts("shell: command not found.");
-            }
+            do {
+                ++pos;
+            } while (*pos > ' ');
+        }
+        ++argc;
+        *pos = 0;
+    }
+
+    if (!argc) {
+        return;
+    }
+
+    /* then we fill the argv array */
+    char *argv[argc + 1];
+    argv[argc] = NULL;
+    pos = line;
+    for (unsigned i = 0; i < argc; ++i) {
+        while (!*pos) {
+            ++pos;
+        }
+        if (*pos == '"') {
+            ++pos;
+        }
+        argv[i] = pos;
+        while (*pos) {
+            ++pos;
+        }
+    }
+
+    /* then we call the appropriate handler */
+    shell_command_handler_t handler = find_handler(shell->command_list, argv[0]);
+    if (handler != NULL) {
+        handler(argc, argv);
+    }
+    else {
+        if (strcmp("help", argv[0]) == 0) {
+            print_help(shell->command_list);
+        }
+        else {
+            puts("shell: command not found.");
         }
     }
 }