From 087056c03fd1584e648ab8d47093ca019aae58aa Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Sat, 5 Oct 2013 19:44:12 +0200
Subject: [PATCH] add a shell setenv command

---
 doc/shell.txt | 10 +++++++++-
 src/input.cpp | 14 +++++++++-----
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/doc/shell.txt b/doc/shell.txt
index 1369df80a9..793a9fc8de 100644
--- a/doc/shell.txt
+++ b/doc/shell.txt
@@ -12,7 +12,7 @@ shell command :h3
 
 shell cmd args :pre
 
-cmd = {cd} or {mkdir} or {mv} or {rm} or {rmdir} or arbitrary command :ulb,l
+cmd = {cd} or {mkdir} or {mv} or {rm} or {rmdir} or {setenv} or arbitrary command :ulb,l
   {cd} arg = dir
     dir = directory to change to
   {mkdir} args = dir1 dir2 ...
@@ -24,6 +24,9 @@ cmd = {cd} or {mkdir} or {mv} or {rm} or {rmdir} or arbitrary command :ulb,l
     file1,file2 = one or more filenames to delete
   {rmdir} args = dir1 dir2 ...
     dir1,dir2 = one or more directories to delete
+  {setenv} args = name value
+    name = name of the environment variable
+    value = value of the environment variable
   anything else is passed as a command to the shell for direct execution :pre
 :ule
 
@@ -35,6 +38,7 @@ shell mkdir tmp1 tmp2 tmp3
 shell rmdir tmp1
 shell mv log.lammps hold/log.1
 shell rm TMP/file1 TMP/file2
+shell setenv LAMMPS_POTENTIALS ../../potentials
 shell my_setup file1 10 file2
 shell my_post_process 100 dump.out :pre
 
@@ -72,6 +76,10 @@ The {rmdir} cmd executes the Unix "rmdir" command to remove one or
 more directories.  A directory must be empty to be successfully
 removed.
 
+The {setenv} cmd defines or updates an environment variable directly.
+Since this command does not pass through the shell, no shell variable
+expansion or globbing is performed, but the value string used literally.
+
 Any other cmd is passed as-is to the shell along with its arguments as
 one string, invoked by the C-library system() call.  For example,
 these lines in your input script:
diff --git a/src/input.cpp b/src/input.cpp
index 24b2016a26..1e40d1e4f4 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -980,11 +980,11 @@ void Input::shell()
   if (narg < 1) error->all(FLERR,"Illegal shell command");
 
   if (strcmp(arg[0],"cd") == 0) {
-    if (narg != 2) error->all(FLERR,"Illegal shell command");
+    if (narg != 2) error->all(FLERR,"Illegal shell cd command");
     chdir(arg[1]);
 
   } else if (strcmp(arg[0],"mkdir") == 0) {
-    if (narg < 2) error->all(FLERR,"Illegal shell command");
+    if (narg < 2) error->all(FLERR,"Illegal shell mkdir command");
 #if !defined(WINDOWS) && !defined(__MINGW32__)
     if (me == 0)
       for (int i = 1; i < narg; i++)
@@ -992,19 +992,23 @@ void Input::shell()
 #endif
 
   } else if (strcmp(arg[0],"mv") == 0) {
-    if (narg != 3) error->all(FLERR,"Illegal shell command");
+    if (narg != 3) error->all(FLERR,"Illegal shell mv command");
     if (me == 0) rename(arg[1],arg[2]);
 
   } else if (strcmp(arg[0],"rm") == 0) {
-    if (narg < 2) error->all(FLERR,"Illegal shell command");
+    if (narg < 2) error->all(FLERR,"Illegal shell rm command");
     if (me == 0)
       for (int i = 1; i < narg; i++) unlink(arg[i]);
 
   } else if (strcmp(arg[0],"rmdir") == 0) {
-    if (narg < 2) error->all(FLERR,"Illegal shell command");
+    if (narg < 2) error->all(FLERR,"Illegal shell rmdir command");
     if (me == 0)
       for (int i = 1; i < narg; i++) rmdir(arg[i]);
 
+  } else if (strcmp(arg[0],"setenv") == 0) {
+    if (narg != 3) error->all(FLERR,"Illegal shell setenv command");
+    setenv(arg[1],arg[2],1);
+
   // use work string to concat args back into one string separated by spaces
   // invoke string in shell via system()