diff --git a/src/input.cpp b/src/input.cpp
index 7201b69578..dc2c140fd7 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -15,6 +15,7 @@
 #include "stdio.h"
 #include "stdlib.h"
 #include "string.h"
+#include "ctype.h"
 #include "input.h"
 #include "style_command.h"
 #include "universe.h"
@@ -117,20 +118,24 @@ Input::~Input()
 
 void Input::file()
 {
-  int n;
+  int m,n;
 
   while (1) {
     
-    // read one line from input script
+    // read a line from input script
     // if line ends in continuation char '&', concatenate next line(s)
-    // n = str length of line
-    
+    // n = length of line including str terminator, 0 if end of file
+    // m = position of last printable char in line or -1 if blank line
+
     if (me == 0) {
-      if (fgets(line,MAXLINE,infile) == NULL) n = 0;
-      else n = strlen(line) + 1;
-      while (n >= 3 && line[n-3] == '&') {
-	if (fgets(&line[n-3],MAXLINE-n+3,infile) == NULL) n = 0;
+      m = 0;
+      while (1) {
+	if (fgets(&line[m],MAXLINE-m,infile) == NULL) n = 0;
 	else n = strlen(line) + 1;
+	if (n == 0) break;
+	m = n-2;
+	while (m >= 0 && isspace(line[m])) m--;
+	if (m < 0 || line[m] != '&') break;
       }
     }
 
@@ -516,7 +521,10 @@ void Input::echo()
 
 void Input::ifthenelse()
 {
-  if (narg != 5 && narg != 7) error->all("Illegal if command");
+  if (narg < 5) error->all("Illegal if command");
+
+  // flag = 0 for "then"
+  // flag = 1 for "else"
 
   int flag = 0;
   if (strcmp(arg[1],"==") == 0) {
@@ -533,16 +541,35 @@ void Input::ifthenelse()
     if (atof(arg[0]) >= atof(arg[2])) flag = 1;
   } else error->all("Illegal if command");
 
+  // first = arg index of first "then" or "else" command
+  // last = arg index of last "then" or "else" command
+  
+  int iarg,first,last;
+
   if (strcmp(arg[3],"then") != 0) error->all("Illegal if command");
-  if (narg == 7 && strcmp(arg[5],"else") != 0) 
-    error->all("Illegal if command");
+  if (flag) {
+    iarg = first = 4;
+    while (iarg < narg && strcmp(arg[iarg],"else") != 0) iarg++;
+    last = iarg-1;
+  } else {
+    iarg = 4;
+    while (iarg < narg && strcmp(arg[iarg],"else") != 0) iarg++;
+    if (iarg == narg) error->all("Illegal if command");
+    first = iarg+1;
+    last = narg-1;
+  }
 
-  char str[128] = "\0";
-  if (flag) strcpy(str,arg[4]);
-  else if (narg == 7) strcpy(str,arg[6]);
-  strcat(str,"\n");
+  if (last-first < 0) error->all("Illegal if command");
 
-  if (strlen(str) > 1) char *tmp = one(str);
+  // execute the list of commands
+
+  char str[256];
+  for (int i = first; i <= last; i++) {
+    if (strlen(arg[i]) == 0) error->all("Illegal if command");
+    strcpy(str,arg[i]);
+    strcat(str,"\n");
+    char *tmp = one(str);
+  }
 }
 
 /* ---------------------------------------------------------------------- */
@@ -638,15 +665,22 @@ void Input::next_command()
 
 void Input::print()
 {
-  if (narg != 1) error->all("Illegal print command");
+  if (narg == 0) error->all("Illegal print command");
 
   // substitute for $ variables (no printing)
+  // print args one at a time, separated by spaces
 
-  substitute(arg[0],0);
+  for (int i = 0; i < narg; i++) {
+    substitute(arg[i],0);
+    if (me == 0) {
+      if (screen) fprintf(screen,"%s ",arg[i]);
+      if (logfile) fprintf(logfile,"%s ",arg[i]);
+    }
+  }
 
   if (me == 0) {
-    if (screen) fprintf(screen,"%s\n",arg[0]);
-    if (logfile) fprintf(logfile,"%s\n",arg[0]);
+    if (screen) fprintf(screen,"\n");
+    if (logfile) fprintf(logfile,"\n");
   }
 }
 
diff --git a/src/run.cpp b/src/run.cpp
index ef38951736..029761a895 100644
--- a/src/run.cpp
+++ b/src/run.cpp
@@ -55,7 +55,7 @@ void Run::command(int narg, char **arg)
   int preflag = 1;
   int postflag = 1;
   int nevery = 0;
-  char *commandstr = NULL;
+  int first,last,ncommands;
     
   int iarg = 1;
   while (iarg < narg) {
@@ -86,24 +86,18 @@ void Run::command(int narg, char **arg)
       else error->all("Illegal run command");
       iarg += 2;
 
-    // generate commandstr if last arg is not NULL
-    // commandstr = concatenation of all remaining args
-    // if an arg has spaces, enclose in quotes since input parser removed them
+      // all remaining args are commands
+      // first,last = arg index of first/last commands
+      // set ncommands = 0 if single command and it is NULL
 
     } else if (strcmp(arg[iarg],"every") == 0) {
       if (iarg+3 > narg) error->all("Illegal run command");
       nevery = atoi(arg[iarg+1]);
       if (nevery <= 0) error->all("Illegal run command");
-      if (strcmp(arg[iarg+2],"NULL") != 0) {
-	commandstr = new char[MAXLINE];
-	commandstr[0] = '\0';
-	for (int jarg = iarg+2; jarg < narg; jarg++) {
-	  if (strchr(arg[jarg],' ')) strcat(commandstr,"\"");
-	  strcat(commandstr,arg[jarg]);
-	  if (strchr(arg[jarg],' ')) strcat(commandstr,"\"");
-	  strcat(commandstr," ");
-	}
-      }
+      first = iarg+2;
+      last = narg-1;
+      ncommands = last-first + 1;
+      if (ncommands == 1 && strcmp(arg[first],"NULL") == 0) ncommands = 0;
       iarg = narg;
     } else error->all("Illegal run command");
   }
@@ -112,6 +106,21 @@ void Run::command(int narg, char **arg)
 
   if (uptoflag) nsteps -= update->ntimestep;
 
+  // if nevery, make copies of arg strings that are commands
+  // required because re-parsing commands during run will wipe out args
+
+  char **commands = NULL;
+  if (nevery && ncommands > 0) {
+    commands = new char*[ncommands];
+    ncommands = 0;
+    for (int i = first; i <= last; i++) {
+      int n = strlen(arg[i]) + 1;
+      commands[ncommands] = new char[n];
+      strcpy(commands[ncommands],arg[i]);
+      ncommands++;
+    }
+  }
+
   // error check
 
   if (uptoflag && nsteps < 0)
@@ -156,7 +165,7 @@ void Run::command(int narg, char **arg)
     Finish finish(lmp);
     finish.end(postflag);
 
-  // perform multiple runs optionally interleaved with invocation of a command
+  // perform multiple runs optionally interleaved with invocation command(s)
   // use start/stop to set begin/end step
   // if pre or 1st iteration of multiple runs, do System init/setup,
   //   else just init timer and setup output
@@ -195,12 +204,13 @@ void Run::command(int narg, char **arg)
       if (postflag || nleft <= nsteps) finish.end(1);
       else finish.end(0);
 
-      // command string may invoke computes via command with variable
-      // so wrap with clearstep/addstep
+      // wrap command invocation with clearstep/addstep
+      // since a command may invoke computes via variables
 
-      if (commandstr) {
+      if (ncommands) {
 	modify->clearstep_compute();
-	char *command = input->one(commandstr);
+	for (int i = 0; i < ncommands; i++)
+	  char *command = input->one(commands[i]);
 	modify->addstep_compute(update->ntimestep + nevery);
       }
 
@@ -212,5 +222,9 @@ void Run::command(int narg, char **arg)
   update->whichflag = 0;
   update->firststep = update->laststep = 0;
   update->beginstep = update->endstep = 0;
-  delete [] commandstr;
+
+  if (commands) {
+    for (int i = 0; i < ncommands; i++) delete [] commands[i];
+    delete [] commands;
+  }
 }