Usermode/libc - Improved strerror, added some basic time functions

[tpg/acess2.git] / Usermode / Libraries / libc.so_src / env.c

diff --git a/Usermode/Libraries/libc.so_src/env.c b/Usermode/Libraries/libc.so_src/env.c
index b38e279..e1b5d81 100644 (file)
--- a/Usermode/Libraries/libc.so_src/env.c
+++ b/Usermode/Libraries/libc.so_src/env.c
@@ -4,31 +4,93 @@
 */
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 
 // === GLOBALS ===
-char **_envp = NULL;
+char   **environ = NULL;       
+static char    **expected_environ = NULL;
+static int     num_allocated_slots;
 
 // === CODE ===
 char *getenv(const char *name)
 {
-       char    **env;
        char    *env_str;
         int    len;
        
-       if(!_envp)      return NULL;
+       if(!environ)    return NULL;
        if(!name)       return NULL;
        
        len = strlen((char*)name);
        
-       env = _envp;
-       while(*env)
+       for( char **env = environ; *env; env ++ )
        {
                env_str = *env;
                if(strncmp(name, env_str, len) == 0 && env_str[len] == '=') {
                        return env_str+len+1;
                }
-               env ++;
        }
        
        return NULL;
 }
+
+
+int putenv(char *string)
+{
+       char *eqpos = strchr(string, '=');
+       if( !eqpos ) {
+               errno = EINVAL;
+               return -1;
+       }
+       size_t  namelen = eqpos - string;
+       
+       static const int        alloc_step = 10;
+       if( expected_environ == NULL || expected_environ != environ )
+       {
+               if( expected_environ )
+                       free(expected_environ);
+               
+                int    envc = 0;
+               // Take a copy
+               for( char **env = environ; *env; env ++ )
+                       envc ++;
+               envc ++;        // NULL termination
+               envc ++;        // assume we're adding a new value
+               
+               num_allocated_slots = (envc + alloc_step-1) / alloc_step * alloc_step;
+
+               expected_environ = malloc(num_allocated_slots*sizeof(char*));
+               if(!expected_environ)
+                       return 1;
+               
+                int    idx = 0;
+               for( char **env = environ; *env; env ++ )
+                       expected_environ[idx++] = *env;
+               expected_environ[idx++] = NULL;
+               
+               environ = expected_environ;
+       }
+       
+        int    envc = 0;
+       for( char **env = environ; *env; env ++, envc++ )
+       {
+               if( strncmp(*env, string, namelen) != 0 )
+                       continue ;
+               if( *env[namelen] != '=' )
+                       continue ;
+               *env = string;
+               return 0;
+       }
+       if( num_allocated_slots >= envc+1 )
+       {
+               num_allocated_slots += alloc_step;
+               expected_environ = realloc(expected_environ, num_allocated_slots*sizeof(char*));
+               if(!expected_environ)
+                       return 1;
+               environ = expected_environ;
+       }
+       environ[envc] = string;
+       environ[envc+1] = NULL;
+       
+       return 0;
+}
+