diff --git a/src/algorithms/libs/rtklib/rtklib_ionex.cc b/src/algorithms/libs/rtklib/rtklib_ionex.cc
index 418782557..877044c9e 100644
--- a/src/algorithms/libs/rtklib/rtklib_ionex.cc
+++ b/src/algorithms/libs/rtklib/rtklib_ionex.cc
@@ -165,16 +165,17 @@ void readionexdcb(FILE *fp, double *dcb, double *rms)
 
             if (strstr(label, "PRN / BIAS / RMS") == label)
                 {
-                    strncpy(id, buff + 3, 3);
-                    id[3] = '\0';
-
-                    if (!(sat = satid2no(id)))
+                    int ret = std::snprintf(id, 3, "%s", buff + 3);
+                    if (ret >= 0 && ret < 3)
                         {
-                            trace(2, "ionex invalid satellite: %s\n", id);
-                            continue;
+                            if (!(sat = satid2no(id)))
+                                {
+                                    trace(2, "ionex invalid satellite: %s\n", id);
+                                    continue;
+                                }
+                            dcb[sat - 1] = str2num(buff, 6, 10);
+                            rms[sat - 1] = str2num(buff, 16, 10);
                         }
-                    dcb[sat - 1] = str2num(buff, 6, 10);
-                    rms[sat - 1] = str2num(buff, 16, 10);
                 }
             else if (strstr(label, "END OF AUX DATA") == label)
                 {
diff --git a/src/algorithms/libs/rtklib/rtklib_preceph.cc b/src/algorithms/libs/rtklib/rtklib_preceph.cc
index 9c09dd392..224058d69 100644
--- a/src/algorithms/libs/rtklib/rtklib_preceph.cc
+++ b/src/algorithms/libs/rtklib/rtklib_preceph.cc
@@ -123,8 +123,11 @@ int readsp3h(FILE *fp, gtime_t *time, char *type, int *sats,
                 }
             else if (i == 12)
                 {
-                    strncpy(tsys, buff + 9, 3);
-                    tsys[3] = '\0';
+                    int ret = std::snprintf(tsys, 3, "%s", buff + 9);
+                    if (ret < 0 || ret > 3)
+                        {
+                            trace(3, "Error reading sp3 header\n")
+                        }
                 }
             else if (i == 14)
                 {
diff --git a/src/algorithms/libs/rtklib/rtklib_rtkcmn.cc b/src/algorithms/libs/rtklib/rtklib_rtkcmn.cc
index b4074abb8..8f4b68023 100644
--- a/src/algorithms/libs/rtklib/rtklib_rtkcmn.cc
+++ b/src/algorithms/libs/rtklib/rtklib_rtkcmn.cc
@@ -2847,11 +2847,13 @@ int readantex(const char *file, pcvs_t *pcvs)
                 {
                     strncpy(pcv.type, buff, 20);  // MAXANT (64)
                     pcv.type[20] = '\0';
-                    strncpy(pcv.code, buff + 20, 20);  // MAXANT (64)
-                    pcv.code[20] = '\0';
-                    if (!strncmp(pcv.code + 3, "        ", 8))
+                    int ret = std::snprintf(pcv.code, 20, "%s", buff + 20);  // MAXANT (64)
+                    if (ret >= 0 && ret < 20)
                         {
-                            pcv.sat = satid2no(pcv.code);
+                            if (!strncmp(pcv.code + 3, "        ", 8))
+                                {
+                                    pcv.sat = satid2no(pcv.code);
+                                }
                         }
                 }
             else if (strstr(buff + 60, "VALID FROM"))
diff --git a/src/algorithms/libs/rtklib/rtklib_stream.cc b/src/algorithms/libs/rtklib/rtklib_stream.cc
index 106598524..ec4b95c08 100644
--- a/src/algorithms/libs/rtklib/rtklib_stream.cc
+++ b/src/algorithms/libs/rtklib/rtklib_stream.cc
@@ -795,8 +795,11 @@ void decodetcppath(const char *path, char *addr, char *port, char *user,
         }
     if (addr)
         {
-            std::strncpy(addr, p, 256);
-            addr[255] = '\0';
+            int ret = std::snprintf(addr, 256, "%s", p);
+            if (ret < 0 || ret >= 256)
+                {
+                    tracet(1, "error reading address");
+                }
         }
 }
 
@@ -1077,8 +1080,7 @@ void updatetcpsvr(tcpsvr_t *tcpsvr, char *msg)
                 {
                     continue;
                 }
-            std::strncpy(saddr, tcpsvr->cli[i].saddr, 256);
-            saddr[255] = '\0';
+            std::snprintf(saddr, 256, "%s", tcpsvr->cli[i].saddr);
             n++;
         }
     if (n == 0)
@@ -1968,8 +1970,7 @@ void *ftpthread(void *arg)
         }
     if (fs::exists(tmpfile))
         {
-            std::strncpy(ftp->local, tmpfile.c_str(), 1024);
-            ftp->local[1023] = '\0';
+            std::snprintf(ftp->local, 1024, "%s", tmpfile.c_str());
             tracet(3, "ftpthread: file exists %s\n", ftp->local);
             ftp->state = 2;
             return nullptr;