diff --git a/src/EXTRA-FIX/fix_ttm_mod.cpp b/src/EXTRA-FIX/fix_ttm_mod.cpp
index 335acdd853..6ad3ca1b0a 100644
--- a/src/EXTRA-FIX/fix_ttm_mod.cpp
+++ b/src/EXTRA-FIX/fix_ttm_mod.cpp
@@ -74,14 +74,13 @@ static constexpr double SHIFT = 0.0;
 /* ---------------------------------------------------------------------- */
 
 FixTTMMod::FixTTMMod(LAMMPS *lmp, int narg, char **arg) :
-  Fix(lmp, narg, arg),
-  random(nullptr), gfactor1(nullptr), gfactor2(nullptr), ratio(nullptr), flangevin(nullptr),
-  T_electron(nullptr), T_electron_old(nullptr), net_energy_transfer(nullptr),
-  net_energy_transfer_all(nullptr)
+    Fix(lmp, narg, arg), infile(nullptr), outfile(nullptr), random(nullptr), gfactor1(nullptr),
+    gfactor2(nullptr), ratio(nullptr), flangevin(nullptr), T_electron(nullptr),
+    T_electron_old(nullptr), net_energy_transfer(nullptr), net_energy_transfer_all(nullptr)
 {
   if (lmp->citeme) lmp->citeme->add(cite_fix_ttm_mod);
 
-  if (narg < 8) error->all(FLERR,"Illegal fix ttm/mod command");
+  if (narg < 8) utils::missing_cmd_args(FLERR, "fix ttm/mod", error);
 
   vector_flag = 1;
   size_vector = 2;
@@ -103,27 +102,29 @@ FixTTMMod::FixTTMMod(LAMMPS *lmp, int narg, char **arg) :
   int iarg = 8;
   while (iarg < narg) {
     if (strcmp(arg[iarg],"set") == 0) {
-      if (iarg+2 > narg) error->all(FLERR,"Illegal fix ttm/mod command");
+      if (iarg+2 > narg) utils::missing_cmd_args(FLERR, "fix ttm/mod set", error);
       tinit = utils::numeric(FLERR,arg[iarg+1],false,lmp);
       if (tinit <= 0.0)
         error->all(FLERR,"Fix ttm/mod initial temperature must be > 0.0");
       iarg += 2;
     } else if (strcmp(arg[iarg],"infile") == 0) {
-      if (iarg+2 > narg) error->all(FLERR,"Illegal fix ttm/mod command");
+      if (iarg+2 > narg) utils::missing_cmd_args(FLERR, "fix ttm/mod infile", error);
+      delete[] infile;
       infile = utils::strdup(arg[iarg+1]);
       iarg += 2;
     } else if (strcmp(arg[iarg],"outfile") == 0) {
-      if (iarg+3 > narg) error->all(FLERR,"Illegal fix ttm/mod command");
+      if (iarg+3 > narg) utils::missing_cmd_args(FLERR, "fix ttm/mod outfile", error);
+      delete[] outfile;
       outevery = utils::inumeric(FLERR,arg[iarg+1],false,lmp);
       outfile = utils::strdup(arg[iarg+2]);
       iarg += 3;
-    } else error->all(FLERR,"Illegal fix ttm/mod command");
+    } else error->all(FLERR,"Unknown fix ttm/mod keyword {}", arg[iarg]);
   }
 
   // error check
 
   if (seed <= 0)
-    error->all(FLERR,"Invalid random number seed in fix ttm/mod command");
+    error->all(FLERR,"Invalid random number seed {} in fix ttm/mod command", seed);
   if (nxgrid <= 0 || nygrid <= 0 || nzgrid <= 0)
     error->all(FLERR,"Fix ttm/mod grid sizes must be > 0");
 
@@ -152,7 +153,8 @@ FixTTMMod::FixTTMMod(LAMMPS *lmp, int narg, char **arg) :
   if (v_0 < 0.0) error->all(FLERR,"Fix ttm/mod v_0 must be >= 0.0");
   if (ionic_density <= 0.0) error->all(FLERR,"Fix ttm/mod ionic_density must be > 0.0");
   if (surface_l < 0) error->all(FLERR,"Surface coordinates must be >= 0");
-  if (surface_l >= surface_r) error->all(FLERR, "Left surface coordinate must be less than right surface coordinate");
+  if (surface_l >= surface_r)
+    error->all(FLERR, "Left surface coordinate must be less than right surface coordinate");
 
   // initialize Marsaglia RNG with processor-unique seed
 
@@ -168,10 +170,8 @@ FixTTMMod::FixTTMMod(LAMMPS *lmp, int narg, char **arg) :
   memory->create(T_electron_old,nzgrid,nygrid,nxgrid,"ttm/mod:T_electron_old");
   memory->create(T_electron_first,nzgrid,nygrid,nxgrid,"ttm/mod:T_electron_first");
   memory->create(T_electron,nzgrid,nygrid,nxgrid,"ttm/mod:T_electron");
-  memory->create(net_energy_transfer,nzgrid,nygrid,nxgrid,
-                 "ttm/mod:net_energy_transfer");
-  memory->create(net_energy_transfer_all,nzgrid,nygrid,nxgrid,
-                 "ttm/mod:net_energy_transfer_all");
+  memory->create(net_energy_transfer,nzgrid,nygrid,nxgrid,"ttm/mod:net_energy_transfer");
+  memory->create(net_energy_transfer_all,nzgrid,nygrid,nxgrid,"ttm/mod:net_energy_transfer_all");
 
   flangevin = nullptr;
   grow_arrays(atom->nmax);
diff --git a/src/GRANULAR/fix_wall_gran.cpp b/src/GRANULAR/fix_wall_gran.cpp
index 3336a8a4d7..4832f07849 100644
--- a/src/GRANULAR/fix_wall_gran.cpp
+++ b/src/GRANULAR/fix_wall_gran.cpp
@@ -163,6 +163,7 @@ FixWallGran::FixWallGran(LAMMPS *lmp, int narg, char **arg) :
   } else if (strcmp(arg[iarg],"region") == 0) {
     if (narg < iarg+2) error->all(FLERR,"Illegal fix wall/gran command");
     wallstyle = REGION;
+    delete[] idregion;
     idregion = utils::strdup(arg[iarg+1]);
     iarg += 2;
     // This option is only compatible with fix wall/gran/region
@@ -205,6 +206,7 @@ FixWallGran::FixWallGran(LAMMPS *lmp, int narg, char **arg) :
     } else if (strcmp(arg[iarg],"temperature") == 0) {
       if (iarg+2 > narg) error->all(FLERR,"Illegal fix wall/gran command");
       if (utils::strmatch(arg[iarg+1], "^v_")) {
+        delete[] tstr;
         tstr = utils::strdup(arg[iarg+1] + 2);
       } else {
         Twall = utils::numeric(FLERR,arg[iarg+1],false,lmp);
diff --git a/src/dump_image.cpp b/src/dump_image.cpp
index 9610ef4d9a..abf4d366d5 100644
--- a/src/dump_image.cpp
+++ b/src/dump_image.cpp
@@ -184,12 +184,12 @@ DumpImage::DumpImage(LAMMPS *lmp, int narg, char **arg) :
 
       char *id;
       int igrid,idata,index;
-      int iflag =
-        utils::check_grid_reference((char *) "Dump image",
-                                    arg[iarg+1],nevery,id,
-                                    igrid,idata,index,lmp);
+      int iflag = utils::check_grid_reference((char *) "Dump image", arg[iarg+1], nevery, id,
+                                              igrid,idata,index,lmp);
       if (iflag < 0) error->all(FLERR,"Invalid grid reference in dump image command");
 
+      delete[] id_grid_compute;
+      delete[] id_grid_fix;
       if (iflag == ArgInfo::COMPUTE) id_grid_compute = utils::strdup(id);
       else if (iflag == ArgInfo::FIX) id_grid_fix = utils::strdup(id);
       delete[] id;
@@ -252,6 +252,7 @@ DumpImage::DumpImage(LAMMPS *lmp, int narg, char **arg) :
     } else if (strcmp(arg[iarg],"view") == 0) {
       if (iarg+3 > narg) error->all(FLERR,"Illegal dump image command");
       if (utils::strmatch(arg[iarg+1],"^v_")) {
+        delete[] thetastr;
         thetastr = utils::strdup(arg[iarg+1]+2);
       } else {
         const double theta = utils::numeric(FLERR,arg[iarg+1],false,lmp);
@@ -260,6 +261,7 @@ DumpImage::DumpImage(LAMMPS *lmp, int narg, char **arg) :
         image->theta = DEG2RAD * theta;
       }
       if (utils::strmatch(arg[iarg+2],"^v_")) {
+        delete[] phistr;
         phistr = utils::strdup(arg[iarg+2]+2);
       } else {
         image->phi = DEG2RAD * utils::numeric(FLERR,arg[iarg+2],false,lmp);
@@ -272,14 +274,17 @@ DumpImage::DumpImage(LAMMPS *lmp, int narg, char **arg) :
       else if (strcmp(arg[iarg+1],"d") == 0) cflag = DYNAMIC;
       else error->all(FLERR,"Illegal dump image command");
       if (utils::strmatch(arg[iarg+2],"^v_")) {
+        delete[] cxstr;
         cxstr = utils::strdup(arg[iarg+2]+2);
         cflag = DYNAMIC;
       } else cx = utils::numeric(FLERR,arg[iarg+2],false,lmp);
       if (utils::strmatch(arg[iarg+3],"^v_")) {
+        delete[] cystr;
         cystr = utils::strdup(arg[iarg+3]+2);
         cflag = DYNAMIC;
       } else cy = utils::numeric(FLERR,arg[iarg+3],false,lmp);
       if (utils::strmatch(arg[iarg+4],"^v_")) {
+        delete[] czstr;
         czstr = utils::strdup(arg[iarg+4]+2);
         cflag = DYNAMIC;
       } else cz = utils::numeric(FLERR,arg[iarg+4],false,lmp);
@@ -288,12 +293,15 @@ DumpImage::DumpImage(LAMMPS *lmp, int narg, char **arg) :
     } else if (strcmp(arg[iarg],"up") == 0) {
       if (iarg+4 > narg) error->all(FLERR,"Illegal dump image command");
       if (utils::strmatch(arg[iarg+1],"^v_")) {
+        delete[] upxstr;
         upxstr = utils::strdup(arg[iarg+1]+2);
       } else image->up[0] = utils::numeric(FLERR,arg[iarg+1],false,lmp);
       if (utils::strmatch(arg[iarg+2],"^v_")) {
+        delete[] upystr;
         upystr = utils::strdup(arg[iarg+2]+2);
       } else image->up[1] = utils::numeric(FLERR,arg[iarg+2],false,lmp);
       if (utils::strmatch(arg[iarg+3],"^v_")) {
+        delete[] upzstr;
         upzstr = utils::strdup(arg[iarg+3]+2);
       } else image->up[2] = utils::numeric(FLERR,arg[iarg+3],false,lmp);
       iarg += 4;
@@ -301,6 +309,7 @@ DumpImage::DumpImage(LAMMPS *lmp, int narg, char **arg) :
     } else if (strcmp(arg[iarg],"zoom") == 0) {
       if (iarg+2 > narg) error->all(FLERR,"Illegal dump image command");
       if (utils::strmatch(arg[iarg+1],"^v_")) {
+        delete[] zoomstr;
         zoomstr = utils::strdup(arg[iarg+1]+2);
       } else {
         double zoom = utils::numeric(FLERR,arg[iarg+1],false,lmp);
diff --git a/src/fix_ave_grid.cpp b/src/fix_ave_grid.cpp
index 1b69c5644c..471d4191e7 100644
--- a/src/fix_ave_grid.cpp
+++ b/src/fix_ave_grid.cpp
@@ -42,19 +42,20 @@ enum{DISCARD,KEEP};
 
 static constexpr int OFFSET = 16384;
 
+// clang-format on
 /* ---------------------------------------------------------------------- */
 
 FixAveGrid::FixAveGrid(LAMMPS *lmp, int narg, char **arg) :
-  Fix(lmp, narg, arg), id_bias(nullptr), which(nullptr), argindex(nullptr), ids(nullptr),
-  value2index(nullptr), value2grid(nullptr), value2data(nullptr), grid2d(nullptr), grid3d(nullptr),
-  grid_buf1(nullptr), grid_buf2(nullptr), grid_output(nullptr), grid_sample(nullptr),
-  grid_nfreq(nullptr), grid_running(nullptr), grid_window(nullptr), grid2d_previous(nullptr),
-  grid3d_previous(nullptr), grid_sample_previous(nullptr), grid_nfreq_previous(nullptr),
-  grid_running_previous(nullptr), grid_window_previous(nullptr), bin(nullptr), skip(nullptr),
-  vresult(nullptr)
+    Fix(lmp, narg, arg), id_bias(nullptr), which(nullptr), argindex(nullptr), ids(nullptr),
+    value2index(nullptr), value2grid(nullptr), value2data(nullptr), grid2d(nullptr),
+    grid3d(nullptr), grid_buf1(nullptr), grid_buf2(nullptr), grid_output(nullptr),
+    grid_sample(nullptr), grid_nfreq(nullptr), grid_running(nullptr), grid_window(nullptr),
+    grid2d_previous(nullptr), grid3d_previous(nullptr), grid_sample_previous(nullptr),
+    grid_nfreq_previous(nullptr), grid_running_previous(nullptr), grid_window_previous(nullptr),
+    bin(nullptr), skip(nullptr), vresult(nullptr)
 {
-  if (narg < 10) utils::missing_cmd_args(FLERR,"fix ave/grid", error);
-
+  if (narg < 10) utils::missing_cmd_args(FLERR, "fix ave/grid", error);
+  // clang-format off
   pergrid_flag = 1;
   nevery = utils::inumeric(FLERR,arg[3],false,lmp);
   nrepeat = utils::inumeric(FLERR,arg[4],false,lmp);
@@ -193,7 +194,6 @@ FixAveGrid::FixAveGrid(LAMMPS *lmp, int narg, char **arg) :
   aveflag = ONE;
   nwindow = 0;
   biasflag = 0;
-  id_bias = nullptr;
   adof = domain->dimension;
   cdof = 0.0;
 
@@ -231,6 +231,7 @@ FixAveGrid::FixAveGrid(LAMMPS *lmp, int narg, char **arg) :
       if (iarg+2 > nargnew)
         error->all(FLERR,"Illegal fix ave/grid command");
       biasflag = 1;
+      delete[] id_bias;
       id_bias = utils::strdup(arg[iarg+1]);
       iarg += 2;
 
@@ -347,11 +348,7 @@ FixAveGrid::FixAveGrid(LAMMPS *lmp, int narg, char **arg) :
   // vresult for per-atom variable evaluation
 
   maxatom = 0;
-  bin = nullptr;
-  skip = nullptr;
-
   maxvar = 0;
-  vresult = nullptr;
 
   // nvalid = next step on which end_of_step does something
   // add nvalid to all computes that store invocation times
@@ -372,6 +369,7 @@ FixAveGrid::~FixAveGrid()
   delete[] argindex;
   for (int m = 0; m < nvalues; m++) delete[] ids[m];
   delete[] ids;
+  delete[] id_bias;
   delete[] value2index;
   delete[] value2grid;
   delete[] value2data;