Enhancement: relocation of the installation directory

[Fravadona]

Hi Inniag,

As I didn't find a way of relocating CHAP after compilation, I added a basic one that may prove useful for other people. It enables a user to compile CHAP and install it wherever he wants (that's he normal workflow) and then move the install directory to another place.

--- chap-version_0_9_1/include/config/config.hpp.orig	2018-05-02 13:22:36.000000000 +0200
+++ chap-version_0_9_1/include/config/config.hpp	2019-12-09 12:20:15.276330444 +0100
@@ -25,6 +25,7 @@
 #ifndef CONFIG_HPP
 #define CONFIG_HPP
 
+#include <cstdlib>
 #include <string>
 
 #include <gromacs/utility/programcontext.h>
@@ -38,7 +39,12 @@
 extern "C" inline std::string
 chapInstallBase()
 {
-    return std::string(g_CHAP_INSTALL_BASE);
+    const char* e_CHAP_INSTALL_BASE = std::getenv("CHAP_INSTALL_BASE");
+    if ( e_CHAP_INSTALL_BASE != NULL) {
+        return std::string(e_CHAP_INSTALL_BASE);
+    } else {
+        return std::string(g_CHAP_INSTALL_BASE);
+    }
 }
 
 
--- chap-version_0_9_1/src/main.cpp.orig	2018-05-02 13:22:36.000000000 +0200
+++ chap-version_0_9_1/src/main.cpp	2019-12-11 20:41:44.217021435 +0100
@@ -21,6 +21,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
+#include <limits.h>
 
 #include <vector>
 
@@ -33,6 +34,20 @@
 
 int main(int argc, char **argv)
 {
+    char buf[PATH_MAX];
+    readlink("/proc/self/exe", buf, PATH_MAX - 1);
+
+    // CHAP full binary path
+    std::string fbp(buf);
+    // CHAP install base path
+    std::string ibp = fbp.substr(0, fbp.rfind("/bin/"));
+    // GROMACS GMXLIB path
+    std::string ggp = ibp + "/share/gromacs/top";
+
+    // set environement variables
+    setenv("CHAP_INSTALL_BASE", ibp.c_str(), 0);
+    setenv("GMXLIB", ggp.c_str(), 0);
+
     // print front matter:
     FrontMatter::print();
 

Incidentally, I also removed the hardcoded '/chap/' sub-directory because it is more usefull to install a program directly in the prefix provided by the user instead of adding a sub-directory inside that prefix.

--- chap-version_0_9_1/CMakeLists.txt.orig	2018-05-02 13:22:36.000000000 +0200
+++ chap-version_0_9_1/CMakeLists.txt	2019-12-06 21:41:00.975176714 +0100
@@ -175,9 +175,9 @@
 #------------------------------------------------------------------------------
 
 # where to install executable on the system:
-install(TARGETS chap DESTINATION ${CMAKE_INSTALL_PREFIX}/chap/bin)
+install(TARGETS chap DESTINATION ${CMAKE_INSTALL_PREFIX}/bin)
 
 # also install data and scripts:
-install(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/share DESTINATION ${CMAKE_INSTALL_PREFIX}/chap)
-install(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/scripts DESTINATION ${CMAKE_INSTALL_PREFIX}/chap USE_SOURCE_PERMISSIONS)
+install(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/share DESTINATION ${CMAKE_INSTALL_PREFIX})
+install(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/scripts DESTINATION ${CMAKE_INSTALL_PREFIX} USE_SOURCE_PERMISSIONS)
 
--- chap-version_0_9_1/src/trajectory-analysis/chap_trajectory_analysis.cpp.orig	2018-05-02 13:22:36.000000000 +0200
+++ chap-version_0_9_1/src/trajectory-analysis/chap_trajectory_analysis.cpp	2019-12-09 13:52:36.745685228 +0100
@@ -708,7 +708,7 @@
 
     // base path to location of van-der-Waals radius databases:
     std::string radiusFilePath = chapInstallBase() +
-            std::string("/chap/share/data/vdwradii/");
+            std::string("/share/data/vdwradii/");
 
     // select appropriate database file:
     if( pfVdwRadiusDatabase_ == eVdwRadiusDatabaseHoleAmberuni )
@@ -779,7 +779,7 @@
 
     // base path to location of hydrophobicity databases:
     std::string hydrophobicityFilePath = chapInstallBase() + 
-            std::string("/chap/share/data/hydrophobicity/");
+            std::string("/share/data/hydrophobicity/");
     
     // select appropriate database file:
     if( hydrophobicityDatabase_ == eHydrophobicityDatabaseHessa2005 )
@@ -1921,7 +1921,7 @@
 
     // load colour palettes from JSON file:
     std::string paletteFilePath = chapInstallBase() + 
-            std::string("/chap/share/data/palettes/");
+            std::string("/share/data/palettes/");
     std::string paletteFileName = paletteFilePath + "default.json";
     auto palettes = ColourPaletteProvider::fromJsonFile(paletteFileName);
 

I hope that will prove usefull,
Cheers.

PS: Patch file with all the previous code :
version_0_9_1_relocation.patch.txt