diff --git a/Makefile b/Makefile
index fe3b7da..38e712f 100644
--- a/Makefile
+++ b/Makefile
@@ -41,7 +41,7 @@ test: $(BINDIR)/$(NAME)
 clean:
 	rm $(ODIR)/*.o
 
-clear: clean
+clear:
 	rm $(BINDIR)/$(NAME)
 
 install: $(BINDIR)/$(NAME)
diff --git a/commands/apt_fetch b/commands/apt_fetch
index b4e3286..8d037c1 100644
--- a/commands/apt_fetch
+++ b/commands/apt_fetch
@@ -1,2 +1,2 @@
-sudo apt update >/dev/null 2>&1 || exit
+sudo apt update >/dev/null || return $?
 apt list --upgradable 2>/dev/null | tail -n +2 | awk -F "/" '{print $1" "$2}' | tr -d ']' | awk '{print $1" "$7" -> "$3}'
diff --git a/commands/pacman_fetch b/commands/pacman_fetch
index b2969a3..5d5ca9a 100644
--- a/commands/pacman_fetch
+++ b/commands/pacman_fetch
@@ -2,5 +2,6 @@ CHECKUPDATES_DB="${TMPDIR:-/tmp}/checkup-db-${USER}/"
 DBPath="$(pacman-conf DBPath)"
 mkdir -p "$CHECKUPDATES_DB"
 ln -sf "${DBPath}/local" "$CHECKUPDATES_DB" > /dev/null 2>&1
-fakeroot pacman -Sy --dbpath "$CHECKUPDATES_DB" --logfile /dev/null >/dev/null 2>&1
+fakeroot pacman -Sy --dbpath "$CHECKUPDATES_DB" --logfile /dev/null >/dev/null || return $?
 pacman -Qu --dbpath "$CHECKUPDATES_DB/" 2> /dev/null | grep -v '\[.*\]'
+return 0
diff --git a/include/commands.h b/include/commands.h
index f810b06..da5fdaf 100644
--- a/include/commands.h
+++ b/include/commands.h
@@ -2,8 +2,8 @@
 #define COMMANDS_H
 
 // pacman
-#define PACMAN_FETCH_COMMAND              "CHECKUPDATES_DB=\"${TMPDIR:-/tmp}/checkup-db-${USER}/\"\nDBPath=\"$(pacman-conf DBPath)\"\nmkdir -p \"$CHECKUPDATES_DB\"\nln -sf \"${DBPath}/local\" \"$CHECKUPDATES_DB\" > /dev/null 2>&1\nfakeroot pacman -Sy --dbpath \"$CHECKUPDATES_DB\" --logfile /dev/null >/dev/null 2>&1\npacman -Qu --dbpath \"$CHECKUPDATES_DB/\" 2> /dev/null | grep -v '\\[.*\\]'"
-#define AUR_FETCH_COMMAND                 "yay -Qau 2>/dev/null"
+#define PACMAN_FETCH_COMMAND              "CHECKUPDATES_DB=\"${TMPDIR:-/tmp}/checkup-db-${USER}/\"\nDBPath=\"$(pacman-conf DBPath)\"\nmkdir -p \"$CHECKUPDATES_DB\"\nln -sf \"${DBPath}/local\" \"$CHECKUPDATES_DB\" > /dev/null 2>&1\nfakeroot pacman -Sy --dbpath \"$CHECKUPDATES_DB\" --logfile /dev/null >/dev/null || return $?\npacman -Qu --dbpath \"$CHECKUPDATES_DB/\" 2> /dev/null | grep -v '\\[.*\\]'\nreturn 0"
+#define AUR_FETCH_COMMAND                 "yay -Qau"
 
 #define PACMAN_UPDATE_COMMAND             "sudo pacman -Syu"
 #define PACMAN_UPDATE_COMMAND_NOCONFIRM   "sudo pacman -Syu --noconfirm"
@@ -17,7 +17,7 @@
 #define PACMAN_LOCAL_SIZE_CUT_COMMAND     " |grep 'Installed Size'|cut -d':' -f2|tr -d ' '|cut -d'i' -f1 | tr -d 'B'|numfmt --from=iec|tr -d '\n'"
 
 // apt/dpkg
-#define APT_FETCH_COMMAND                 "sudo apt update >/dev/null 2>&1 || exit\napt list --upgradable 2>/dev/null | tail -n +2 | awk -F \"/\" '{print $1\" \"$2}' | tr -d ']' | awk '{print $1\" \"$7\" -> \"$3}'"
+#define APT_FETCH_COMMAND                 "sudo apt update >/dev/null || return $?\napt list --upgradable 2>/dev/null | tail -n +2 | awk -F \"/\" '{print $1\" \"$2}' | tr -d ']' | awk '{print $1\" \"$7\" -> \"$3}'"
 #define APT_UPDATE_COMMAND                "sudo apt upgrade"
 #define APT_UPDATE_COMMAND_NOCONFIRM      "echo y | sudo apt upgrade"
 
diff --git a/include/fetch.hpp b/include/fetch.hpp
index 74ee8df..19a140b 100644
--- a/include/fetch.hpp
+++ b/include/fetch.hpp
@@ -4,8 +4,8 @@
 #include "repos.hpp"
 
 //functions
-void fetch_update(repo_update* r, const std::string& name, const std::string& command);
+int fetch_update(repo_update* r, const std::string& name, const std::string& command);
 
-void import_sizes(repo_update* ru, const char* ext_info_command, const char* loc_info_command, const char* ext_cut_command, const char* loc_cut_command);
+int import_sizes(repo_update* ru, const char* ext_info_command, const char* loc_info_command, const char* ext_cut_command, const char* loc_cut_command);
 
 #endif //FETCH_HPP
diff --git a/include/package_man.hpp b/include/package_man.hpp
index e8b650f..4802d4b 100644
--- a/include/package_man.hpp
+++ b/include/package_man.hpp
@@ -12,8 +12,8 @@ extern package_manager cur_pkgman;
 // functions
 bool exec_find(const std::string& name);
 
-void pacman_process(bool yay);
+int pacman_process(bool yay);
 
-void apt_process();
+int apt_process();
 
 #endif //PACKAGE_MAN_HPP
diff --git a/src/fetch.cpp b/src/fetch.cpp
index 1645933..5bd600c 100644
--- a/src/fetch.cpp
+++ b/src/fetch.cpp
@@ -10,54 +10,57 @@
 #include "commands.h"
 
 //functions
-void fetch_update(repo_update* r, const std::string& name, const std::string& command)
+int fetch_update(repo_update* r, const std::string& name, const std::string& command)
 {
-    r->packages.clear();
-    r->name=name;
-    r->name_max_length=0;
-    r->vcur_max_length=0;
-    r->vnew_max_length=0;
-    std::string str=ztd::sh(command);
+  r->packages.clear();
+  r->name=name;
+  r->name_max_length=0;
+  r->vcur_max_length=0;
+  r->vnew_max_length=0;
+  std::pair<std::string, int> cp = ztd::shp(command);
+  if(cp.second != 0)
+    return cp.second;
+  std::string str=cp.first;
 
-    unsigned long int i=0,j=0;
-    while(i<str.size())
-    {
-      package_update pkg;
-      //name
-      while( str[i]!=' ' )
-        i++;
-      pkg.name = str.substr(j,i-j);
-      if(pkg.name.size() > r->name_max_length)
-        r->name_max_length = pkg.name.size();
-      //end name
+  unsigned long int i=0,j=0;
+  while(i<str.size())
+  {
+    package_update pkg;
+    //name
+    while( str[i]!=' ' )
       i++;
-      //current version
-      j=i;
-      while( str[i]!=' ' )
-        i++;
-      pkg.current_version = str.substr(j,i-j);
-      if(pkg.current_version.size() > r->vcur_max_length)
-        r->vcur_max_length = pkg.current_version.size();
-      //end current version
+    pkg.name = str.substr(j,i-j);
+    if(pkg.name.size() > r->name_max_length)
+      r->name_max_length = pkg.name.size();
+    //end name
+    i++;
+    //current version
+    j=i;
+    while( str[i]!=' ' )
       i++;
-      //skip arrow
-      while( str[i]!=' ' )
-        i++;
-      //end arrow
+    pkg.current_version = str.substr(j,i-j);
+    if(pkg.current_version.size() > r->vcur_max_length)
+      r->vcur_max_length = pkg.current_version.size();
+    //end current version
+    i++;
+    //skip arrow
+    while( str[i]!=' ' )
       i++;
-      //new version
-      j=i;
-      while( str[i]!='\n' )
-        i++;
-      pkg.new_version = str.substr(j,i-j);
-      if(pkg.new_version.size() > r->vnew_max_length)
-        r->vnew_max_length = pkg.new_version.size();
-      //end new version
+    //end arrow
+    i++;
+    //new version
+    j=i;
+    while( str[i]!='\n' )
       i++;
-      j=i;
-      r->packages.push_back(pkg);
-    }
-
+    pkg.new_version = str.substr(j,i-j);
+    if(pkg.new_version.size() > r->vnew_max_length)
+      r->vnew_max_length = pkg.new_version.size();
+    //end new version
+    i++;
+    j=i;
+    r->packages.push_back(pkg);
+  }
+  return 0;
 }
 
 
@@ -84,7 +87,7 @@ void get_loc_size(package_update* pkg, const char* info_command, const char* cut
     pkg->current_install_size = 0;
 }
 
-void import_sizes(repo_update* ru, const char* ext_info_command, const char* loc_info_command, const char* ext_cut_command, const char* loc_cut_command)
+int import_sizes(repo_update* ru, const char* ext_info_command, const char* loc_info_command, const char* ext_cut_command, const char* loc_cut_command)
 {
   const unsigned int n=ru->packages.size();
   #pragma omp parallel for
@@ -105,4 +108,5 @@ void import_sizes(repo_update* ru, const char* ext_info_command, const char* loc
     ru->current_install_size += pkg.current_install_size;
   }
   ru->net_size = (long int) ru->new_install_size - (long int) ru->current_install_size;
+  return 0;
 }
diff --git a/src/main.cpp b/src/main.cpp
index 928917a..4b8066e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -5,11 +5,6 @@
 #include "options.hpp"
 #include "package_man.hpp"
 
-long unsigned int new_download_size=0;
-long unsigned int new_install_size=0;
-long unsigned int current_install_size=0;
-long int net_size=0;
-
 int main(int argc, char* argv[])
 {
   //option process start
@@ -26,7 +21,7 @@ int main(int argc, char* argv[])
     return 1;
   }
 
-  if( !combine_target ) //no target -> all
+  if( !combine_target ) //no target -> all targets
   {
     opt_repo = true;
     opt_aur = true;
@@ -36,7 +31,7 @@ int main(int argc, char* argv[])
     opt_pall = true;
   }
 
-  if ( opt_pall ) //all -> list + sizes
+  if ( opt_pall ) //pall -> list + sizes
   {
     opt_plist=true;
     opt_psizes=true;
@@ -77,12 +72,12 @@ int main(int argc, char* argv[])
   switch(cur_pkgman)
   {
     case pacman :
-      pacman_process(exec_find("yay")); break;
+      return pacman_process(exec_find("yay")); break;
     case apt :
-      apt_process(); break;
-    default : std::cerr << "Unsupported package manager\n"; break;
+      return apt_process(); break;
+    default :
+      std::cerr << "Unsupported package manager\n";
+      return 1;
+      break;
   }
-
-
-  return 0;
 }
diff --git a/src/package_man.cpp b/src/package_man.cpp
index 8ed26b5..c01c3bb 100644
--- a/src/package_man.cpp
+++ b/src/package_man.cpp
@@ -34,12 +34,14 @@ void repo_print_process(repo_update& ru, ztd::color cl, bool print_size=true)
   }
 }
 
-void pacman_process(bool yay)
+int pacman_process(bool yay)
 {
+  int r=0, r2=0;
+
   if(!exec_find("pacman"))
   {
     std::cerr << "pacman not found\n";
-    return;
+    return 1;
   }
   //fetch
   if(combine_fetch)
@@ -49,14 +51,18 @@ void pacman_process(bool yay)
       #pragma omp section
       {
         if(opt_repo)
-          fetch_update(&repo, "REPO", PACMAN_FETCH_COMMAND);
+          r = fetch_update(&repo, "REPO", PACMAN_FETCH_COMMAND);
       }
       #pragma omp section
       {
         if(opt_aur && yay)
-          fetch_update(&aur, "AUR", AUR_FETCH_COMMAND);
+          r2 = fetch_update(&aur, "AUR", AUR_FETCH_COMMAND);
       }
     }
+    if(r!=0)
+      return r;
+    if(r2!=0)
+      return r2;
   }
 
   //process
@@ -65,8 +71,10 @@ void pacman_process(bool yay)
     //size fetch
     if( combine_size )
     {
-      import_sizes(&repo, PACMAN_EXT_INFO_COMMAND, PACMAN_LOCAL_INFO_COMMAND, PACMAN_EXT_SIZE_CUT_COMMAND, PACMAN_LOCAL_SIZE_CUT_COMMAND);
+      r = import_sizes(&repo, PACMAN_EXT_INFO_COMMAND, PACMAN_LOCAL_INFO_COMMAND, PACMAN_EXT_SIZE_CUT_COMMAND, PACMAN_LOCAL_SIZE_CUT_COMMAND);
     }
+    if(r!=0)
+      return r;
 
     repo_print_process(repo, ztd::color::b_white);
 
@@ -79,9 +87,12 @@ void pacman_process(bool yay)
     {
       signal(SIGINT, SIG_IGN);
       if(opt_noconfirm)
-        system(PACMAN_UPDATE_COMMAND_NOCONFIRM);
+        r = ztd::shr(PACMAN_UPDATE_COMMAND_NOCONFIRM);
       else
-        system(PACMAN_UPDATE_COMMAND);
+        r = ztd::shr(PACMAN_UPDATE_COMMAND);
+
+      if(r!=0)
+        return r;
     }
 
 
@@ -99,11 +110,15 @@ void pacman_process(bool yay)
     {
       signal(SIGINT, SIG_IGN);
       if(opt_noconfirm)
-        system(AUR_UPDATE_COMMAND_NOCONFIRM);
+        r = ztd::shr(AUR_UPDATE_COMMAND_NOCONFIRM, true);
       else
-        system(AUR_UPDATE_COMMAND);
+        r = ztd::shr(AUR_UPDATE_COMMAND, true);
+
+      if(r!=0)
+        return r;
     }
   }
+  return 0;
 }
 
 std::string apt_getrepo()
@@ -120,31 +135,39 @@ std::string apt_getrepo()
   return "UNKNOWN";
 }
 
-void apt_process()
+int apt_process()
 {
+  int r=0;
+
   if(!exec_find("apt"))
   {
     std::cerr << "apt not found\n";
-    return;
+    return 1;
   }
   if(!exec_find("apt-cache"))
   {
     std::cerr << "apt-cache not found\n";
-    return;
+    return 1;
   }
   if(!exec_find("dpkg"))
   {
     std::cerr << "dpkg not found\n";
-    return;
+    return 1;
   }
-  if(combine_fetch)
+
+  if( combine_fetch )
   {
-    fetch_update(&repo, apt_getrepo(), APT_FETCH_COMMAND);
+    r = fetch_update(&repo, apt_getrepo(), APT_FETCH_COMMAND);
   }
+  if(r!=0)
+    return r;
+
   if( combine_size )
   {
-    import_sizes(&repo, APT_EXT_INFO_COMMAND, APT_LOCAL_INFO_COMMAND, APT_EXT_SIZE_CUT_COMMAND, APT_LOCAL_SIZE_CUT_COMMAND);
+    r = import_sizes(&repo, APT_EXT_INFO_COMMAND, APT_LOCAL_INFO_COMMAND, APT_EXT_SIZE_CUT_COMMAND, APT_LOCAL_SIZE_CUT_COMMAND);
   }
+  if(r!=0)
+    return r;
 
   repo_print_process(repo, ztd::color::b_white);
 
@@ -157,8 +180,12 @@ void apt_process()
   {
     signal(SIGINT, SIG_IGN);
     if(opt_noconfirm)
-      system(APT_UPDATE_COMMAND_NOCONFIRM);
+      r = ztd::shr(APT_UPDATE_COMMAND_NOCONFIRM, true);
     else
-      system(APT_UPDATE_COMMAND);
+      r = ztd::shr(APT_UPDATE_COMMAND, true);
+
+    if(r!=0)
+      return r;
   }
+  return 0;
 }