diff --git a/src/ao_two_e_ints/integrals_in_map_slave.irp.f b/src/ao_two_e_ints/integrals_in_map_slave.irp.f
index a91bdecb..122fa2ac 100644
--- a/src/ao_two_e_ints/integrals_in_map_slave.irp.f
+++ b/src/ao_two_e_ints/integrals_in_map_slave.irp.f
@@ -116,7 +116,7 @@ subroutine ao_two_e_integrals_in_map_slave(thread,iproc)
       exit
     endif
     if (task_id == 0) exit
-    read(task,*) j, l
+    call sscanf_dd(task, j, l)
     integer, external :: task_done_to_taskserver
     call compute_ao_integrals_jl(j,l,n_integrals,buffer_i,buffer_value)
     if (task_done_to_taskserver(zmq_to_qp_run_socket,worker_id,task_id) == -1) then
diff --git a/src/cipsi/run_selection_slave.irp.f b/src/cipsi/run_selection_slave.irp.f
index c2ba2379..91bd3a38 100644
--- a/src/cipsi/run_selection_slave.irp.f
+++ b/src/cipsi/run_selection_slave.irp.f
@@ -52,7 +52,7 @@ subroutine run_selection_slave(thread,iproc,energy)
       ctask = ctask - 1
     else
       integer :: i_generator, N, subset, bsize
-      read(task,*) subset, i_generator, N
+      call sscanf_ddd(task, subset, i_generator, N)
       if(buf%N == 0) then
         ! Only first time
         call create_selection_buffer(N, N*2, buf)
diff --git a/src/utils/c_funcs.c b/src/utils/c_funcs.c
index 5b7035fb..16b53256 100644
--- a/src/utils/c_funcs.c
+++ b/src/utils/c_funcs.c
@@ -1,6 +1,40 @@
 #include <unistd.h>
+#include <stdio.h>
+#include <string.h>
 
 void usleep_c(int s)
 {
   usleep((useconds_t) s);
 }
+
+void sscanf_ssds_c(const char* str, char* s1, char* s2, int* i, char* s3)
+{
+  sscanf(str, "%s %s %d %s", s1, s2, i, s3);
+  s1[strlen(s1)] = ' ';
+  s2[strlen(s2)] = ' ';
+  s3[strlen(s3)] = ' ';
+}
+
+void sscanf_dd_c(const char* str, int* i1, int* i2)
+{
+  sscanf(str, "%d %d", i1, i2);
+}
+
+void sscanf_ddd_c(const char* str, int* i1, int* i2, int* i3)
+{
+  sscanf(str, "%d %d %d", i1, i2, i3);
+}
+
+void sscanf_ss_c(const char* str, char* s1, char* s2)
+{
+  sscanf(str, "%s %s", s1, s2);
+  s1[strlen(s1)] = ' ';
+  s2[strlen(s2)] = ' ';
+}
+
+void sscanf_sd_c(const char* str, char* s1, int* i)
+{
+  sscanf(str, "%s %d", s1, i);
+  s1[strlen(s1)] = ' ';
+}
+
diff --git a/src/utils/c_functions.f90 b/src/utils/c_functions.f90
index 425aafd6..65d4ad62 100644
--- a/src/utils/c_functions.f90
+++ b/src/utils/c_functions.f90
@@ -2,20 +2,133 @@ module c_functions
   use iso_c_binding
 
   interface
-    subroutine usleep_c(us) bind (C,name="usleep_c")
-      use iso_c_binding
-      integer(c_int), value :: us
-    end subroutine usleep_c
+     subroutine usleep_c(us) bind (C,name="usleep_c")
+       use iso_c_binding
+       integer(c_int), value :: us
+     end subroutine usleep_c
   end interface
 
-end module
+  interface
+     integer(c_int) function atoi_c(a) bind (C,name="atoi")
+       use iso_c_binding
+       character(kind=c_char), intent(in) :: a(*)
+     end function atoi_c
+  end interface
 
-subroutine usleep(us)
+  interface
+     subroutine sscanf_ss_c(str,s1, s2) bind (C)
+       use iso_c_binding
+       character(kind=c_char), intent(in ) :: str(*)
+       character(kind=c_char), intent(out) :: s1(*),s2(*)
+     end subroutine sscanf_ss_c
+  end interface
+
+  interface
+     subroutine sscanf_ssds_c(str, s1, s2, i, s3) bind (C)
+       use iso_c_binding
+       character(kind=c_char), intent(in ) :: str(*)
+       character(kind=c_char), intent(out) :: s1(*),s2(*),s3(*)
+       integer(kind=c_int)   , intent(out) :: i
+     end subroutine sscanf_ssds_c
+  end interface
+
+  interface
+     subroutine sscanf_dd_c(str, i1, i2) bind (C)
+       use iso_c_binding
+       character(kind=c_char), intent(in ) :: str(*)
+       integer(kind=c_int)   , intent(out) :: i1, i2
+     end subroutine sscanf_dd_c
+  end interface
+
+  interface
+     subroutine sscanf_ddd_c(str, i1, i2, i3) bind (C)
+       use iso_c_binding
+       character(kind=c_char), intent(in ) :: str(*)
+       integer(kind=c_int)   , intent(out) :: i1, i2, i3
+     end subroutine sscanf_ddd_c
+  end interface
+
+  interface
+     subroutine sscanf_sd_c(str,s1, i) bind (C)
+       use iso_c_binding
+       character(kind=c_char), intent(in ) :: str(*)
+       character(kind=c_char), intent(out) :: s1(*)
+       integer(kind=c_int)   , intent(out) :: i
+     end subroutine sscanf_sd_c
+  end interface
+
+contains
+
+  integer function atoi(a)
+    implicit none
+    character(len=*), intent(in) :: a
+    atoi = atoi_c(trim(a)//c_null_char)
+  end function atoi
+
+end module c_functions
+
+subroutine sscanf_ss(str, s1,s2)
   use c_functions
   use iso_c_binding
   implicit none
+  character(*), intent(in)  :: str
+  character(*), intent(out) :: s1,s2
+  s1 = ' '
+  s2 = ' '
+  call sscanf_ss_c(trim(str)//c_null_char, s1, s2)
+end subroutine sscanf_ss
+
+subroutine sscanf_sd(str, s1,i)
+  use c_functions
+  use iso_c_binding
+  implicit none
+  character(*), intent(in)  :: str
+  character(*), intent(out) :: s1
+  integer, intent(out)      :: i
+  s1 = ' '
+  call sscanf_sd_c(trim(str)//c_null_char, s1, i)
+end subroutine sscanf_sd
+
+subroutine sscanf_ssds(str, s1,s2,i,s3)
+  use c_functions
+  use iso_c_binding
+  implicit none
+  character(*), intent(in)  :: str
+  character(*), intent(out) :: s1,s2,s3
+  integer, intent(out)      :: i
+  s1 = ' '
+  s2 = ' '
+  s3 = ' '
+  call sscanf_ssds_c(trim(str)//c_null_char, s1, s2, i, s3)
+end subroutine sscanf_ssds
+
+subroutine sscanf_dd(str, i1,i2)
+  use c_functions
+  use iso_c_binding
+  implicit none
+  character(*), intent(in)  :: str
+  integer, intent(out)      :: i1, i2
+  call sscanf_dd_c(trim(str)//c_null_char, i1, i2)
+end subroutine sscanf_dd
+
+subroutine sscanf_ddd(str, i1,i2,i3)
+  use c_functions
+  use iso_c_binding
+  implicit none
+  character(*), intent(in)  :: str
+  integer, intent(out)      :: i1, i2, i3
+  call sscanf_ddd_c(trim(str)//c_null_char, i1, i2, i3)
+end subroutine sscanf_ddd
+
+
+subroutine usleep(us)
+  use iso_c_binding
+  use c_functions
+  implicit none
   integer, intent(in) :: us
   integer(c_int) :: u
   u = us
   call usleep_c(u)
-end
+end subroutine usleep
+
+
diff --git a/src/zmq/utils.irp.f b/src/zmq/utils.irp.f
index 058f6bca..93dbd16a 100644
--- a/src/zmq/utils.irp.f
+++ b/src/zmq/utils.irp.f
@@ -16,6 +16,7 @@ END_PROVIDER
  BEGIN_PROVIDER [ character*(128), qp_run_address ]
 &BEGIN_PROVIDER [ integer, zmq_port_start ]
   use f77_zmq
+  use c_functions
   implicit none
   BEGIN_DOC
   ! Address of the qp_run socket
@@ -32,14 +33,15 @@ END_PROVIDER
   do i=len(buffer),1,-1
     if ( buffer(i:i) == ':') then
       qp_run_address = trim(buffer(1:i-1))
-      read(buffer(i+1:), *, err=10,end=10) zmq_port_start
+      zmq_port_start = atoi(buffer(i+1:))
       exit
     endif
   enddo
-  return
-  10 continue
-  print *,  irp_here, ': Error in read'
-  stop -1
+
+  if (zmq_port_start == 0) then
+    print *,  irp_here, ': zmq_port_start is 0'
+    stop -1
+  endif
 END_PROVIDER
 
  BEGIN_PROVIDER [ character*(128), zmq_socket_pull_tcp_address    ]
@@ -84,6 +86,7 @@ end
 
 subroutine switch_qp_run_to_master
   use f77_zmq
+  use c_functions
   implicit none
   BEGIN_DOC
   ! Address of the master qp_run socket
@@ -102,16 +105,17 @@ subroutine switch_qp_run_to_master
   do i=len(buffer),1,-1
     if ( buffer(i:i) == ':') then
       qp_run_address = trim(buffer(1:i-1))
-      read(buffer(i+1:), *, end=10, err=10) zmq_port_start
+      zmq_port_start = atoi(buffer(i+1:))
       exit
     endif
   enddo
   call reset_zmq_addresses
 
   return
-  10 continue
-  print *,  irp_here, ': Error in read'
-  stop -1
+  if (zmq_port_start == 0) then
+    print *,  irp_here, ': zmq_port_start is 0'
+    stop -1
+  endif
 end
 
 
@@ -650,12 +654,17 @@ integer function connect_to_taskserver(zmq_to_qp_run_socket,worker_id,thread)
   rc = f77_zmq_recv(zmq_to_qp_run_socket, message, 510, 0)
   message = trim(message(1:rc))
   if(message(1:5) == "error") then
-    go to 10
+    connect_to_taskserver = -1
+    return
   end if
-  read(message,*, end=10, err=10) reply, state, worker_id, address
+
+  call sscanf_ssds(message, reply, state, worker_id, address)
+
   if (trim(reply) /= 'connect_reply') then
-    go to 10
+    connect_to_taskserver = -1
+    return
   endif
+
   if (trim(state) /= zmq_state) then
     integer, external :: disconnect_from_taskserver_state
     if (disconnect_from_taskserver_state(zmq_to_qp_run_socket, worker_id, state) == -1) then
@@ -663,13 +672,8 @@ integer function connect_to_taskserver(zmq_to_qp_run_socket,worker_id,thread)
       continue
     endif
     connect_to_taskserver = -1
-    return
   endif
 
-  return
-  10 continue
-!  print *,  irp_here//': '//trim(message)
-  connect_to_taskserver = -1
 end
 
 integer function disconnect_from_taskserver(zmq_to_qp_run_socket, worker_id)
@@ -698,7 +702,7 @@ integer function disconnect_from_taskserver_state(zmq_to_qp_run_socket, worker_i
   character*(512)                :: message, reply
   character*(128)                :: state_tmp
 
-  disconnect_from_taskserver_state = 0
+  disconnect_from_taskserver_state = -1
 
   write(message,*) 'disconnect '//trim(state), worker_id
 
@@ -718,21 +722,15 @@ integer function disconnect_from_taskserver_state(zmq_to_qp_run_socket, worker_i
   rc = min(510,rc)
   message = trim(message(1:rc))
 
-  read(message,*, end=10, err=10) reply, state_tmp
-  if ((trim(reply) == 'disconnect_reply').and.(trim(state_tmp) == trim(state))) then
-    return
-  endif
-  if (trim(message) == 'error Wrong state') then
-    disconnect_from_taskserver_state = -1
-    return
-  else if (trim(message) == 'error No job is running') then
-    disconnect_from_taskserver_state = -1
+  call sscanf_ss(message, reply, state_tmp)
+
+  if (trim(state_tmp) /= trim(state)) then
     return
   endif
 
-  return
-  10 continue
-  disconnect_from_taskserver_state = -1
+  if ((trim(reply) == 'disconnect_reply')) then
+    disconnect_from_taskserver_state = 0
+  endif
 end
 
 integer function add_task_to_taskserver(zmq_to_qp_run_socket,task)
@@ -898,7 +896,7 @@ integer function get_task_from_taskserver(zmq_to_qp_run_socket,worker_id,task_id
 
   character*(1024)                :: message
   character*(64)                 :: reply
-  integer                        :: rc, sze
+  integer                        :: rc, sze, i
 
   get_task_from_taskserver = 0
 
@@ -912,12 +910,15 @@ integer function get_task_from_taskserver(zmq_to_qp_run_socket,worker_id,task_id
   endif
 
   task_id = 0
-  message = repeat(' ',1024)
+  message = ' '
   rc = f77_zmq_recv(zmq_to_qp_run_socket, message, 1024, 0)
-  rc = min(64,rc)
-  read(message(1:rc),*, end=10, err=10) reply
-  if (trim(reply) == 'get_task_reply') then
-    read(message(1:rc),*, end=10, err=10) reply, task_id
+  i = 1
+  do while (message(i:i) /= ' ')
+    i = i+1
+  enddo
+  reply = message(1:i-1)
+  if (reply == 'get_task_reply') then
+    call sscanf_sd(message, reply, task_id)
     rc = 15
     do while (rc < 1024 .and. message(rc:rc) == ' ')
       rc += 1
@@ -937,15 +938,12 @@ integer function get_task_from_taskserver(zmq_to_qp_run_socket,worker_id,task_id
     get_task_from_taskserver = -1
     return
   endif
-  return
-
-  10 continue
-  get_task_from_taskserver = -1
 
 end
 
 
 integer function get_tasks_from_taskserver(zmq_to_qp_run_socket,worker_id,task_id,task,n_tasks)
+  use c_functions
   use f77_zmq
   implicit none
   BEGIN_DOC
@@ -1000,7 +998,7 @@ integer function get_tasks_from_taskserver(zmq_to_qp_run_socket,worker_id,task_i
       return
     endif
     rc = min(1024,rc)
-    read(message(1:rc),*, end=10, err=10) task_id(i)
+    task_id(i) = atoi(message(1:rc))
     if (task_id(i) == 0) then
       task(i) = 'terminate'
       n_tasks = i