diff --git a/src/ADIOS/dump_atom_adios.cpp b/src/ADIOS/dump_atom_adios.cpp
index a56f31b6c5..3e637b02d7 100644
--- a/src/ADIOS/dump_atom_adios.cpp
+++ b/src/ADIOS/dump_atom_adios.cpp
@@ -81,44 +81,18 @@ DumpAtomADIOS::~DumpAtomADIOS()
 
 void DumpAtomADIOS::openfile()
 {
-    if (multifile) {
-        // if one file per timestep, replace '*' with current timestep
-        char *filestar = strdup(filename);
-        char *filecurrent = new char[strlen(filestar) + 16];
-        char *ptr = strchr(filestar, '*');
-        *ptr = '\0';
-        if (padflag == 0)
-            snprintf(filecurrent, sizeof(filecurrent), "%s" BIGINT_FORMAT "%s",
-                     filestar, update->ntimestep, ptr + 1);
-        else {
-            char bif[8], pad[16];
-            strcpy(bif, BIGINT_FORMAT);
-            snprintf(pad, sizeof(pad), "%%s%%0%d%s%%s", padflag, &bif[1]);
-            snprintf(filecurrent, sizeof(filecurrent), pad, filestar,
-                     update->ntimestep, ptr + 1);
-        }
-        internal->fh =
-            internal->io.Open(filecurrent, adios2::Mode::Write, world);
-        if (!internal->fh) {
-            char str[128];
-            snprintf(str, sizeof(str), "Cannot open dump file %s", filecurrent);
-            error->one(FLERR, str);
-        }
-        free(filestar);
-        delete[] filecurrent;
-    } else {
-        if (!singlefile_opened) {
-            internal->fh =
-                internal->io.Open(filename, adios2::Mode::Write, world);
-            if (!internal->fh) {
-                char str[128];
-                snprintf(str, sizeof(str), "Cannot open dump file %s",
-                         filename);
-                error->one(FLERR, str);
-            }
-            singlefile_opened = 1;
-        }
+  if (multifile) {
+    // if one file per timestep, replace '*' with current timestep
+    auto filecurrent = utils::star_subst(filename, update->ntimestep, padflag);
+    internal->fh = internal->io.Open(filecurrent, adios2::Mode::Write, world);
+    if (!internal->fh) error->one(FLERR, "Cannot open dump file {}", filecurrent);
+  } else {
+    if (!singlefile_opened) {
+      internal->fh = internal->io.Open(filename, adios2::Mode::Write, world);
+      if (!internal->fh) error->one(FLERR, "Cannot open dump file {}", filename);
+      singlefile_opened = 1;
     }
+  }
 }
 
 /* ---------------------------------------------------------------------- */
diff --git a/src/ADIOS/dump_custom_adios.cpp b/src/ADIOS/dump_custom_adios.cpp
index a947f02d35..263f15349c 100644
--- a/src/ADIOS/dump_custom_adios.cpp
+++ b/src/ADIOS/dump_custom_adios.cpp
@@ -93,42 +93,18 @@ DumpCustomADIOS::~DumpCustomADIOS()
 
 void DumpCustomADIOS::openfile()
 {
-    if (multifile) {
-        // if one file per timestep, replace '*' with current timestep
-        char *filestar = strdup(filename);
-        char *filecurrent = new char[strlen(filestar) + 16];
-        char *ptr = strchr(filestar, '*');
-        *ptr = '\0';
-        if (padflag == 0)
-            sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar,
-                    update->ntimestep, ptr + 1);
-        else {
-            char bif[8], pad[16];
-            strcpy(bif, BIGINT_FORMAT);
-            sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-            sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-        }
-        internal->fh =
-            internal->io.Open(filecurrent, adios2::Mode::Write, world);
-        if (!internal->fh) {
-            char str[128];
-            sprintf(str, "Cannot open dump file %s", filecurrent);
-            error->one(FLERR, str);
-        }
-        free(filestar);
-        delete[] filecurrent;
-    } else {
-        if (!singlefile_opened) {
-            internal->fh =
-                internal->io.Open(filename, adios2::Mode::Write, world);
-            if (!internal->fh) {
-                char str[128];
-                sprintf(str, "Cannot open dump file %s", filename);
-                error->one(FLERR, str);
-            }
-            singlefile_opened = 1;
-        }
+  if (multifile) {
+    // if one file per timestep, replace '*' with current timestep
+    auto filecurrent = utils::star_subst(filename, update->ntimestep, padflag);
+    internal->fh = internal->io.Open(filecurrent, adios2::Mode::Write, world);
+    if (!internal->fh) error->one(FLERR, "Cannot open dump file {}", filecurrent);
+  } else {
+    if (!singlefile_opened) {
+      internal->fh = internal->io.Open(filename, adios2::Mode::Write, world);
+      if (!internal->fh) error->one(FLERR, "Cannot open dump file {}", filename);
+      singlefile_opened = 1;
     }
+  }
 }
 
 /* ---------------------------------------------------------------------- */
diff --git a/src/COMPRESS/dump_atom_gz.cpp b/src/COMPRESS/dump_atom_gz.cpp
index 8bdc025436..3e15d6240d 100644
--- a/src/COMPRESS/dump_atom_gz.cpp
+++ b/src/COMPRESS/dump_atom_gz.cpp
@@ -46,19 +46,7 @@ void DumpAtomGZ::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
diff --git a/src/COMPRESS/dump_atom_zstd.cpp b/src/COMPRESS/dump_atom_zstd.cpp
index aa1c161d73..453efb6972 100644
--- a/src/COMPRESS/dump_atom_zstd.cpp
+++ b/src/COMPRESS/dump_atom_zstd.cpp
@@ -52,19 +52,7 @@ void DumpAtomZstd::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
diff --git a/src/COMPRESS/dump_cfg_gz.cpp b/src/COMPRESS/dump_cfg_gz.cpp
index 8d85e8cf83..dcf85e1fc5 100644
--- a/src/COMPRESS/dump_cfg_gz.cpp
+++ b/src/COMPRESS/dump_cfg_gz.cpp
@@ -48,19 +48,7 @@ void DumpCFGGZ::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
diff --git a/src/COMPRESS/dump_cfg_zstd.cpp b/src/COMPRESS/dump_cfg_zstd.cpp
index 6d70749479..8a3dc32e8d 100644
--- a/src/COMPRESS/dump_cfg_zstd.cpp
+++ b/src/COMPRESS/dump_cfg_zstd.cpp
@@ -54,19 +54,7 @@ void DumpCFGZstd::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
diff --git a/src/COMPRESS/dump_custom_gz.cpp b/src/COMPRESS/dump_custom_gz.cpp
index a8ef1ffe7c..42b15c4146 100644
--- a/src/COMPRESS/dump_custom_gz.cpp
+++ b/src/COMPRESS/dump_custom_gz.cpp
@@ -46,19 +46,7 @@ void DumpCustomGZ::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
diff --git a/src/COMPRESS/dump_custom_zstd.cpp b/src/COMPRESS/dump_custom_zstd.cpp
index c6c7e3592e..e3effe1744 100644
--- a/src/COMPRESS/dump_custom_zstd.cpp
+++ b/src/COMPRESS/dump_custom_zstd.cpp
@@ -56,20 +56,7 @@ void DumpCustomZstd::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar,'*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent,"%s" BIGINT_FORMAT "%s",
-              filestar,update->ntimestep,ptr+1);
-    else {
-      char bif[8],pad[16];
-      strcpy(bif,BIGINT_FORMAT);
-      sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
-      sprintf(filecurrent,pad,filestar,update->ntimestep,ptr+1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
diff --git a/src/COMPRESS/dump_local_gz.cpp b/src/COMPRESS/dump_local_gz.cpp
index c3669e6157..9c04f0cd61 100644
--- a/src/COMPRESS/dump_local_gz.cpp
+++ b/src/COMPRESS/dump_local_gz.cpp
@@ -46,19 +46,7 @@ void DumpLocalGZ::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
diff --git a/src/COMPRESS/dump_local_zstd.cpp b/src/COMPRESS/dump_local_zstd.cpp
index 63af89afcc..4e65702b0e 100644
--- a/src/COMPRESS/dump_local_zstd.cpp
+++ b/src/COMPRESS/dump_local_zstd.cpp
@@ -52,19 +52,7 @@ void DumpLocalZstd::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
diff --git a/src/COMPRESS/dump_xyz_gz.cpp b/src/COMPRESS/dump_xyz_gz.cpp
index 06561c6d9a..9bfead1c5c 100644
--- a/src/COMPRESS/dump_xyz_gz.cpp
+++ b/src/COMPRESS/dump_xyz_gz.cpp
@@ -45,19 +45,7 @@ void DumpXYZGZ::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
diff --git a/src/COMPRESS/dump_xyz_zstd.cpp b/src/COMPRESS/dump_xyz_zstd.cpp
index c4748b4ac3..bb2640b1b8 100644
--- a/src/COMPRESS/dump_xyz_zstd.cpp
+++ b/src/COMPRESS/dump_xyz_zstd.cpp
@@ -51,19 +51,7 @@ void DumpXYZZstd::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
diff --git a/src/MOLFILE/dump_molfile.cpp b/src/MOLFILE/dump_molfile.cpp
index 35e87f94af..bb45680395 100644
--- a/src/MOLFILE/dump_molfile.cpp
+++ b/src/MOLFILE/dump_molfile.cpp
@@ -274,29 +274,12 @@ void DumpMolfile::openfile()
 
     // if one file per timestep, replace '*' with current timestep
 
-    char *filecurrent = new char[strlen(filename) + 16];
-    if (multifile == 0) {
-      strcpy(filecurrent,filename);
-    } else {
-      char *ptr = strchr(filename,'*');
-      char *p1 = filename;
-      char *p2 = filecurrent;
-      while (p1 != ptr)
-        *p2++ = *p1++;
+    std::string filecurrent = filename;
+    if (multifile == 1)
+      filecurrent = utils::star_subst(filename, update->ntimestep, padflag);
 
-      if (padflag == 0) {
-        sprintf(p2,BIGINT_FORMAT "%s",update->ntimestep,ptr+1);
-      } else {
-        char bif[8],pad[16];
-        strcpy(bif,BIGINT_FORMAT);
-        sprintf(pad,"%%0%d%s%%s",padflag,&bif[1]);
-        sprintf(p2,pad,update->ntimestep,ptr+1);
-      }
-    }
-
-    if (mf->open(filecurrent,&natoms))
-      error->one(FLERR,"Cannot open dump file");
-    delete[] filecurrent;
+    if (mf->open(filecurrent.c_str(), &natoms))
+      error->one(FLERR,"Cannot open dump file {}: {}", filecurrent, utils::getsyserror());
   }
 }
 
diff --git a/src/MPIIO/dump_atom_mpiio.cpp b/src/MPIIO/dump_atom_mpiio.cpp
index 522950ab8b..9ba779924f 100644
--- a/src/MPIIO/dump_atom_mpiio.cpp
+++ b/src/MPIIO/dump_atom_mpiio.cpp
@@ -69,19 +69,7 @@ void DumpAtomMPIIO::openfile()
   filecurrent = filename;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0) {
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    } else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = new char[strlen(filecurrent) + 1];
@@ -98,8 +86,8 @@ void DumpAtomMPIIO::openfile()
   }
 
   if (append_flag) {    // append open
-    int err = MPI_File_open(world, filecurrent, MPI_MODE_CREATE | MPI_MODE_APPEND | MPI_MODE_WRONLY,
-                            MPI_INFO_NULL, &mpifh);
+    int err = MPI_File_open(world, filecurrent, MPI_MODE_CREATE | MPI_MODE_APPEND |
+                            MPI_MODE_WRONLY, MPI_INFO_NULL, &mpifh);
     if (err != MPI_SUCCESS)
       error->one(FLERR, "Cannot open dump file {}: {}", filecurrent, utils::getsyserror());
 
@@ -112,8 +100,8 @@ void DumpAtomMPIIO::openfile()
 
   } else {    // replace open
 
-    int err =
-        MPI_File_open(world, filecurrent, MPI_MODE_CREATE | MPI_MODE_WRONLY, MPI_INFO_NULL, &mpifh);
+    int err = MPI_File_open(world, filecurrent, MPI_MODE_CREATE | MPI_MODE_WRONLY,
+                            MPI_INFO_NULL, &mpifh);
     if (err != MPI_SUCCESS)
       error->one(FLERR, "Cannot open dump file {}: {}", filecurrent, utils::getsyserror());
 
diff --git a/src/MPIIO/dump_cfg_mpiio.cpp b/src/MPIIO/dump_cfg_mpiio.cpp
index 978709b787..88072d5adc 100644
--- a/src/MPIIO/dump_cfg_mpiio.cpp
+++ b/src/MPIIO/dump_cfg_mpiio.cpp
@@ -81,20 +81,7 @@ void DumpCFGMPIIO::openfile()
   filecurrent = filename;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar,'*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent,"%s" BIGINT_FORMAT "%s",
-          filestar,update->ntimestep,ptr+1);
-    else {
-      char bif[8],pad[16];
-      strcpy(bif,BIGINT_FORMAT);
-      sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
-      sprintf(filecurrent,pad,filestar,update->ntimestep,ptr+1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = new char[strlen(filecurrent)+1];
@@ -111,12 +98,10 @@ void DumpCFGMPIIO::openfile()
   }
 
   if (append_flag) { // append open
-    int err = MPI_File_open( world, filecurrent, MPI_MODE_CREATE | MPI_MODE_APPEND | MPI_MODE_WRONLY  , MPI_INFO_NULL, &mpifh);
-    if (err != MPI_SUCCESS) {
-      char str[128];
-      sprintf(str,"Cannot open dump file %s",filecurrent);
-      error->one(FLERR,str);
-    }
+    int err = MPI_File_open( world, filecurrent, MPI_MODE_CREATE | MPI_MODE_APPEND |
+                             MPI_MODE_WRONLY, MPI_INFO_NULL, &mpifh);
+    if (err != MPI_SUCCESS) error->one(FLERR, "Cannot open dump file {}", filecurrent);
+
     int myrank;
     MPI_Comm_rank(world,&myrank);
     if (myrank == 0)
@@ -125,15 +110,11 @@ void DumpCFGMPIIO::openfile()
     MPI_File_set_size(mpifh,mpifo+headerSize+sumFileSize);
     currentFileSize = mpifo+headerSize+sumFileSize;
 
-  }
-  else { // replace open
+  } else { // replace open
 
-    int err = MPI_File_open( world, filecurrent, MPI_MODE_CREATE | MPI_MODE_WRONLY  , MPI_INFO_NULL, &mpifh);
-    if (err != MPI_SUCCESS) {
-      char str[128];
-      sprintf(str,"Cannot open dump file %s",filecurrent);
-      error->one(FLERR,str);
-    }
+    int err = MPI_File_open( world, filecurrent, MPI_MODE_CREATE | MPI_MODE_WRONLY,
+                             MPI_INFO_NULL, &mpifh);
+    if (err != MPI_SUCCESS) error->one(FLERR, "Cannot open dump file {}", filecurrent);
     mpifo = 0;
 
     MPI_File_set_size(mpifh,(MPI_Offset) (headerSize+sumFileSize));
diff --git a/src/MPIIO/dump_custom_mpiio.cpp b/src/MPIIO/dump_custom_mpiio.cpp
index 766bd976bc..372b8705b9 100644
--- a/src/MPIIO/dump_custom_mpiio.cpp
+++ b/src/MPIIO/dump_custom_mpiio.cpp
@@ -36,7 +36,6 @@
 
 using namespace LAMMPS_NS;
 
-#define MAX_TEXT_HEADER_SIZE 4096
 #define DUMP_BUF_CHUNK_SIZE 16384
 #define DUMP_BUF_INCREMENT_SIZE 4096
 
@@ -71,7 +70,7 @@ DumpCustomMPIIO::~DumpCustomMPIIO()
 
 void DumpCustomMPIIO::openfile()
 {
-  if (singlefile_opened) {    // single file already opened, so just return after resetting filesize
+  if (singlefile_opened) { // single file already opened, so just return after resetting filesize
     mpifo = currentFileSize;
     MPI_File_set_size(mpifh, mpifo + headerSize + sumFileSize);
     currentFileSize = mpifo + headerSize + sumFileSize;
@@ -84,19 +83,7 @@ void DumpCustomMPIIO::openfile()
   filecurrent = filename;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar, '*');
-    *ptr = '\0';
-    if (padflag == 0) {
-      sprintf(filecurrent, "%s" BIGINT_FORMAT "%s", filestar, update->ntimestep, ptr + 1);
-    } else {
-      char bif[8], pad[16];
-      strcpy(bif, BIGINT_FORMAT);
-      sprintf(pad, "%%s%%0%d%s%%s", padflag, &bif[1]);
-      sprintf(filecurrent, pad, filestar, update->ntimestep, ptr + 1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = new char[strlen(filecurrent) + 1];
diff --git a/src/MPIIO/dump_xyz_mpiio.cpp b/src/MPIIO/dump_xyz_mpiio.cpp
index e4bfe4ef13..c976932b52 100644
--- a/src/MPIIO/dump_xyz_mpiio.cpp
+++ b/src/MPIIO/dump_xyz_mpiio.cpp
@@ -81,20 +81,7 @@ void DumpXYZMPIIO::openfile()
   filecurrent = filename;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar,'*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent,"%s" BIGINT_FORMAT "%s",
-          filestar,update->ntimestep,ptr+1);
-    else {
-      char bif[8],pad[16];
-      strcpy(bif,BIGINT_FORMAT);
-      sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
-      sprintf(filecurrent,pad,filestar,update->ntimestep,ptr+1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = new char[strlen(filecurrent)+1];
@@ -111,12 +98,10 @@ void DumpXYZMPIIO::openfile()
   }
 
   if (append_flag) { // append open
-    int err = MPI_File_open( world, filecurrent, MPI_MODE_CREATE | MPI_MODE_APPEND | MPI_MODE_WRONLY  , MPI_INFO_NULL, &mpifh);
-    if (err != MPI_SUCCESS) {
-      char str[128];
-      sprintf(str,"Cannot open dump file %s",filecurrent);
-      error->one(FLERR,str);
-    }
+    int err = MPI_File_open( world, filecurrent, MPI_MODE_CREATE | MPI_MODE_APPEND |
+                             MPI_MODE_WRONLY  , MPI_INFO_NULL, &mpifh);
+    if (err != MPI_SUCCESS) error->one(FLERR, "Cannot open dump file {}",filecurrent);
+
     int myrank;
     MPI_Comm_rank(world,&myrank);
     if (myrank == 0)
@@ -124,20 +109,15 @@ void DumpXYZMPIIO::openfile()
     MPI_Bcast(&mpifo, 1, MPI_LMP_BIGINT, 0, world);
     MPI_File_set_size(mpifh,mpifo+headerSize+sumFileSize);
     currentFileSize = mpifo+headerSize+sumFileSize;
-  }
-  else { // replace open
+  } else { // replace open
 
-    int err = MPI_File_open( world, filecurrent, MPI_MODE_CREATE |  MPI_MODE_WRONLY  , MPI_INFO_NULL, &mpifh);
-    if (err != MPI_SUCCESS) {
-      char str[128];
-      sprintf(str,"Cannot open dump file %s",filecurrent);
-      error->one(FLERR,str);
-    }
+    int err = MPI_File_open( world, filecurrent, MPI_MODE_CREATE |  MPI_MODE_WRONLY,
+                             MPI_INFO_NULL, &mpifh);
+    if (err != MPI_SUCCESS) error->one(FLERR, "Cannot open dump file {}",filecurrent);
     mpifo = 0;
 
     MPI_File_set_size(mpifh,(MPI_Offset) (headerSize+sumFileSize));
     currentFileSize = (headerSize+sumFileSize);
-
   }
 }
 
@@ -221,8 +201,8 @@ void DumpXYZMPIIO::write()
   performEstimate = 0;
   write_data(nme,buf);
 
-  if (multifile)    MPI_File_close(&mpifh);
-  if (multifile) delete [] filecurrent;
+  if (multifile) MPI_File_close(&mpifh);
+  if (multifile) delete[] filecurrent;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -231,7 +211,7 @@ void DumpXYZMPIIO::init_style()
 {
   // format = copy of default or user-specified line format
 
-  delete [] format;
+  delete[] format;
   char *str;
   if (format_line_user) str = format_line_user;
   else str = format_default;
@@ -246,10 +226,8 @@ void DumpXYZMPIIO::init_style()
 
   if (typenames == nullptr) {
     typenames = new char*[ntypes+1];
-    for (int itype = 1; itype <= ntypes; itype++) {
-      typenames[itype] = new char[12];
-      sprintf(typenames[itype],"%d",itype);
-    }
+    for (int itype = 1; itype <= ntypes; itype++)
+      typenames[itype] = utils::strdup(std::to_string(itype));
   }
 
   // setup function ptr
@@ -267,8 +245,7 @@ void DumpXYZMPIIO::write_header(bigint n)
     headerSize = 0;
     headerSize += sprintf(((char*)&((char*)headerBuffer)[headerSize]),BIGINT_FORMAT "\n",n);
     headerSize += sprintf(&((char*)headerBuffer)[headerSize],"Atoms. Timestep: " BIGINT_FORMAT "\n",update->ntimestep);
-  }
-  else { // write data
+  } else { // write data
 
     if (me == 0)
       MPI_File_write_at(mpifh,mpifo,headerBuffer,headerSize,MPI_CHAR,MPI_STATUS_IGNORE);
diff --git a/src/NETCDF/dump_netcdf.cpp b/src/NETCDF/dump_netcdf.cpp
index d68da35b0b..13dc869021 100644
--- a/src/NETCDF/dump_netcdf.cpp
+++ b/src/NETCDF/dump_netcdf.cpp
@@ -178,7 +178,7 @@ DumpNetCDF::DumpNetCDF(LAMMPS *lmp, int narg, char **arg) :
       for (int j = 0; j < DUMP_NC_MAX_DIMS; j++) {
         perat[inc].field[j] = -1;
       }
-      strncpy(perat[inc].name, mangled.c_str(), NC_FIELD_NAME_MAX);
+      strncpy(perat[inc].name, mangled.c_str(), NC_FIELD_NAME_MAX-1);
       n_perat++;
     }
 
@@ -217,22 +217,9 @@ DumpNetCDF::~DumpNetCDF()
 
 void DumpNetCDF::openfile()
 {
-  char *filecurrent = filename;
-  if (multifile && !singlefile_opened) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar,'*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent,"%s" BIGINT_FORMAT "%s", filestar,update->ntimestep,ptr+1);
-    else {
-      char bif[8],pad[16];
-      strcpy(bif,BIGINT_FORMAT);
-      sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
-      sprintf(filecurrent,pad,filestar,update->ntimestep,ptr+1);
-    }
-    *ptr = '*';
-  }
+  std::string filecurrent = filename;
+  if (multifile && !singlefile_opened)
+    filecurrent = utils::star_subst(filename, update->ntimestep, padflag);
 
   if (thermo && !singlefile_opened) {
     delete[] thermovar;
@@ -291,7 +278,7 @@ void DumpNetCDF::openfile()
       if (singlefile_opened) return;
       singlefile_opened = 1;
 
-      NCERRX( nc_open(filecurrent, NC_WRITE, &ncid), filecurrent );
+      NCERRX( nc_open(filecurrent.c_str(), NC_WRITE, &ncid), filecurrent.c_str() );
 
       // dimensions
       NCERRX( nc_inq_dimid(ncid, NC_FRAME_STR, &frame_dim), NC_FRAME_STR );
@@ -356,7 +343,7 @@ void DumpNetCDF::openfile()
       if (singlefile_opened) return;
       singlefile_opened = 1;
 
-      NCERRX( nc_create(filecurrent, NC_64BIT_DATA, &ncid), filecurrent );
+      NCERRX( nc_create(filecurrent.c_str(), NC_64BIT_DATA, &ncid), filecurrent.c_str() );
 
       // dimensions
       NCERRX( nc_def_dim(ncid, NC_FRAME_STR, NC_UNLIMITED, &frame_dim), NC_FRAME_STR );
diff --git a/src/NETCDF/dump_netcdf_mpiio.cpp b/src/NETCDF/dump_netcdf_mpiio.cpp
index ac281d26a3..dbf95953d7 100644
--- a/src/NETCDF/dump_netcdf_mpiio.cpp
+++ b/src/NETCDF/dump_netcdf_mpiio.cpp
@@ -177,7 +177,7 @@ DumpNetCDFMPIIO::DumpNetCDFMPIIO(LAMMPS *lmp, int narg, char **arg) :
       for (int j = 0; j < DUMP_NC_MPIIO_MAX_DIMS; j++) {
         perat[inc].field[j] = -1;
       }
-      strncpy(perat[inc].name, mangled.c_str(), NC_MPIIO_FIELD_NAME_MAX);
+      strncpy(perat[inc].name, mangled.c_str(), NC_MPIIO_FIELD_NAME_MAX-1);
       n_perat++;
     }
 
@@ -214,22 +214,9 @@ DumpNetCDFMPIIO::~DumpNetCDFMPIIO()
 
 void DumpNetCDFMPIIO::openfile()
 {
-  char *filecurrent = filename;
-  if (multifile && !singlefile_opened) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar,'*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent,"%s" BIGINT_FORMAT "%s", filestar,update->ntimestep,ptr+1);
-    else {
-      char bif[8],pad[16];
-      strcpy(bif,BIGINT_FORMAT);
-      sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
-      sprintf(filecurrent,pad,filestar,update->ntimestep,ptr+1);
-    }
-    *ptr = '*';
-  }
+  std::string filecurrent = filename;
+  if (multifile && !singlefile_opened)
+    filecurrent = utils::star_subst(filename, update->ntimestep, padflag);
 
   if (thermo && !singlefile_opened) {
     delete[] thermovar;
@@ -287,7 +274,8 @@ void DumpNetCDFMPIIO::openfile()
     if (singlefile_opened) return;
     singlefile_opened = 1;
 
-    NCERRX( ncmpi_open(world, filecurrent, NC_WRITE, MPI_INFO_NULL, &ncid), filecurrent );
+    NCERRX( ncmpi_open(world, filecurrent.c_str(), NC_WRITE, MPI_INFO_NULL, &ncid),
+            filecurrent.c_str() );
 
     // dimensions
     NCERRX( ncmpi_inq_dimid(ncid, NC_FRAME_STR, &frame_dim), NC_FRAME_STR );
@@ -352,7 +340,8 @@ void DumpNetCDFMPIIO::openfile()
     if (singlefile_opened) return;
     singlefile_opened = 1;
 
-    NCERRX( ncmpi_create(world, filecurrent, NC_64BIT_DATA, MPI_INFO_NULL, &ncid), filecurrent );
+    NCERRX( ncmpi_create(world, filecurrent.c_str(), NC_64BIT_DATA, MPI_INFO_NULL, &ncid),
+            filecurrent.c_str() );
 
     // dimensions
     NCERRX( ncmpi_def_dim(ncid, NC_FRAME_STR, NC_UNLIMITED, &frame_dim), NC_FRAME_STR );
diff --git a/src/REAXFF/fix_reaxff_species.cpp b/src/REAXFF/fix_reaxff_species.cpp
index 873ba9bbfd..45dec215df 100644
--- a/src/REAXFF/fix_reaxff_species.cpp
+++ b/src/REAXFF/fix_reaxff_species.cpp
@@ -644,29 +644,15 @@ void FixReaxFFSpecies::WriteFormulas(int Nmole, int Nspec)
 
 void FixReaxFFSpecies::OpenPos()
 {
-  char *filecurrent;
-  bigint ntimestep = update->ntimestep;
-
-  filecurrent = (char*) malloc((strlen(filepos)+16)*sizeof(char));
-  char *ptr = strchr(filepos,'*');
-  *ptr = '\0';
-  if (padflag == 0)
-    sprintf(filecurrent,"%s" BIGINT_FORMAT "%s",filepos,ntimestep,ptr+1);
-  else {
-    char bif[8],pad[16];
-    strcpy(bif,BIGINT_FORMAT);
-    sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
-    sprintf(filecurrent,pad,filepos,ntimestep,ptr+1);
-  }
-  *ptr = '*';
-
   if (me == 0) {
-    pos = fopen(filecurrent, "w");
-    if (pos == nullptr) error->one(FLERR,"Cannot open fix reaxff/species position file");
-  } else pos = nullptr;
+    auto filecurrent = utils::star_subst(filepos, update->ntimestep, padflag);
+    pos = fopen(filecurrent.c_str(), "w");
+    if (pos == nullptr)
+      error->one(FLERR, "Cannot open fix reaxff/species position file {}: {}", filecurrent,
+                 utils::getsyserror());
+  } else
+    pos = nullptr;
   multipos_opened = 1;
-
-  free(filecurrent);
 }
 
 /* ---------------------------------------------------------------------- */
diff --git a/src/VTK/dump_vtk.cpp b/src/VTK/dump_vtk.cpp
index d42699c271..e1b4d19713 100644
--- a/src/VTK/dump_vtk.cpp
+++ b/src/VTK/dump_vtk.cpp
@@ -1009,13 +1009,13 @@ void DumpVTK::write_data(int n, double *mybuf)
 /* ---------------------------------------------------------------------- */
 
 void DumpVTK::setFileCurrent() {
-  delete [] filecurrent;
+  delete[] filecurrent;
   filecurrent = nullptr;
 
   char *filestar = filename;
   if (multiproc) {
     if (multiproc > 1) { // if dump_modify fileper or nfile was used
-      delete [] multiname_ex;
+      delete[] multiname_ex;
       multiname_ex = nullptr;
       char *ptr = strchr(filename,'%');
       if (ptr) {
@@ -1034,26 +1034,13 @@ void DumpVTK::setFileCurrent() {
   }
 
   if (multifile == 0) {
-    filecurrent = new char[strlen(filestar) + 1];
-    strcpy(filecurrent, filestar);
+    filecurrent = utils::strdup(filestar);
   } else {
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar,'*');
-    *ptr = '\0';
-    if (padflag == 0) {
-      sprintf(filecurrent,"%s" BIGINT_FORMAT "%s",
-              filestar,update->ntimestep,ptr+1);
-    } else {
-      char bif[8],pad[16];
-      strcpy(bif,BIGINT_FORMAT);
-      sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
-      sprintf(filecurrent,pad,filestar,update->ntimestep,ptr+1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filestar, update->ntimestep, padflag));
   }
 
   // filename of domain box data file
-  delete [] domainfilecurrent;
+  delete[] domainfilecurrent;
   domainfilecurrent = nullptr;
   if (multiproc) {
     // remove '%' character
@@ -1074,21 +1061,9 @@ void DumpVTK::setFileCurrent() {
       domainfilecurrent = new char[strlen(filestar) + 1];
       strcpy(domainfilecurrent, filestar);
     } else {
-      domainfilecurrent = new char[strlen(filestar) + 16];
-      char *ptr = strchr(filestar,'*');
-      *ptr = '\0';
-      if (padflag == 0) {
-        sprintf(domainfilecurrent,"%s" BIGINT_FORMAT "%s",
-                filestar,update->ntimestep,ptr+1);
-      } else {
-        char bif[8],pad[16];
-        strcpy(bif,BIGINT_FORMAT);
-        sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
-        sprintf(domainfilecurrent,pad,filestar,update->ntimestep,ptr+1);
-      }
-      *ptr = '*';
+      domainfilecurrent = utils::strdup(utils::star_subst(filestar, update->ntimestep, padflag));
     }
-    delete [] filestar;
+    delete[] filestar;
     filestar = nullptr;
   } else {
     domainfilecurrent = new char[strlen(filecurrent) + 16];
@@ -1100,7 +1075,7 @@ void DumpVTK::setFileCurrent() {
 
   // filename of parallel file
   if (multiproc && me == 0) {
-    delete [] parallelfilecurrent;
+    delete[] parallelfilecurrent;
     parallelfilecurrent = nullptr;
 
     // remove '%' character and add 'p' to file extension
@@ -1119,24 +1094,11 @@ void DumpVTK::setFileCurrent() {
     *ptr++= 0;
 
     if (multifile == 0) {
-      parallelfilecurrent = new char[strlen(filestar) + 1];
-      strcpy(parallelfilecurrent, filestar);
+      parallelfilecurrent = utils::strdup(filestar);
     } else {
-      parallelfilecurrent = new char[strlen(filestar) + 16];
-      char *ptr = strchr(filestar,'*');
-      *ptr = '\0';
-      if (padflag == 0) {
-        sprintf(parallelfilecurrent,"%s" BIGINT_FORMAT "%s",
-                filestar,update->ntimestep,ptr+1);
-      } else {
-        char bif[8],pad[16];
-        strcpy(bif,BIGINT_FORMAT);
-        sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
-        sprintf(parallelfilecurrent,pad,filestar,update->ntimestep,ptr+1);
-      }
-      *ptr = '*';
+      parallelfilecurrent = utils::strdup(utils::star_subst(filestar, update->ntimestep, padflag));
     }
-    delete [] filestar;
+    delete[] filestar;
     filestar = nullptr;
   }
 }
diff --git a/src/dump.cpp b/src/dump.cpp
index f11f21f71e..2e6df77cd9 100644
--- a/src/dump.cpp
+++ b/src/dump.cpp
@@ -549,20 +549,7 @@ void Dump::openfile()
   if (multiproc) filecurrent = multiname;
 
   if (multifile) {
-    char *filestar = filecurrent;
-    filecurrent = new char[strlen(filestar) + 16];
-    char *ptr = strchr(filestar,'*');
-    *ptr = '\0';
-    if (padflag == 0)
-      sprintf(filecurrent,"%s" BIGINT_FORMAT "%s",
-              filestar,update->ntimestep,ptr+1);
-    else {
-      char bif[8],pad[16];
-      strcpy(bif,BIGINT_FORMAT);
-      sprintf(pad,"%%s%%0%d%s%%s",padflag,&bif[1]);
-      sprintf(filecurrent,pad,filestar,update->ntimestep,ptr+1);
-    }
-    *ptr = '*';
+    filecurrent = utils::strdup(utils::star_subst(filecurrent, update->ntimestep, padflag));
     if (maxfiles > 0) {
       if (numfiles < maxfiles) {
         nameslist[numfiles] = utils::strdup(filecurrent);
@@ -594,7 +581,7 @@ void Dump::openfile()
 
   // delete string with timestep replaced
 
-  if (multifile) delete [] filecurrent;
+  if (multifile) delete[] filecurrent;
 }
 
 /* ----------------------------------------------------------------------