simple example on how to use -pid

utils/misc/callgmsh.c

+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+int main(void)
+{
+  int i, pid;
+  FILE *fp;
+  char str[32];
+
+  for(i = 0; i < 5; i++){
+    system("gmsh -pid fichier.msh fichier.pos > /tmp/gmsh.pid &");
+
+    printf("computing %d...\n", i);
+    sleep(2);
+
+    fp = fopen("/tmp/gmsh.pid", "r");
+    fscanf(fp, "%d", &pid);
+    sprintf(str, "kill %d", pid);
+    system(str);
+  }    
+}