From 1f8fcff74edfbbd8fea7c24bf54f9bb132ddff1d Mon Sep 17 00:00:00 2001
From: Sjoerd van der Berg <harekiet@users.sourceforge.net>
Date: Fri, 18 Oct 2002 09:00:51 +0000
Subject: [PATCH] New environment functions

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@331
---
 src/misc/programs.cpp | 101 ++++++++++++++++++++++--------------------
 1 file changed, 53 insertions(+), 48 deletions(-)

diff --git a/src/misc/programs.cpp b/src/misc/programs.cpp
index aea3fdb8..e5562713 100644
--- a/src/misc/programs.cpp
+++ b/src/misc/programs.cpp
@@ -78,8 +78,6 @@ static Bitu PROGRAMS_Handler(void) {
 
 Program::Program() {
 	/* Find the command line and setup the PSP */
-
-	
 	psp = new DOS_PSP(dos.psp);
 	/* Scan environment for filename */
 	char * envscan=(char *)HostMake(psp->GetEnvironment(),0);
@@ -105,64 +103,71 @@ void Program::WriteOut(const char * format,...) {
 }
 
 
-char * Program::GetEnvStr(char * env_str) {
+bool Program::GetEnvStr(const char * entry,std::string & result) {
 	/* Walk through the internal environment and see for a match */
-/* Taking some short cuts here to not fuck around with memory structure */
-
-	char * envstart=(char *)HostMake(psp->GetEnvironment(),0);
-	size_t len=strlen(env_str);
-	while (*envstart) {
-		if (strncasecmp(env_str,envstart,len)==0 && envstart[len]=='=') {
-				return envstart;
-		}
-		envstart+=strlen(envstart)+1;	
-	}
-	return 0;
+	PhysPt env_read=PhysMake(psp->GetEnvironment(),0);
+	char env_string[1024];
+	result.erase();
+	if (!entry[0]) return false;
+	do 	{
+		MEM_StrCopy(env_read,env_string,1024);
+		if (!env_string[0]) return false;
+		env_read+=strlen(env_string)+1;
+		if (!strchr(env_string,'=')) continue;
+		if (strncasecmp(entry,env_string,strlen(entry))!=0) continue;
+		result=env_string;
+		return true;
+	} while (1);
+	return false;
 };
 
-char * Program::GetEnvNum(Bit32u num) {
-	char * envstart=(char *)HostMake(psp->GetEnvironment(),0);
-	while (*envstart) {
-		if (!num) return envstart;
-		envstart+=strlen(envstart)+1;	
+bool Program::GetEnvNum(Bitu num,std::string & result) {
+	char env_string[1024];
+	PhysPt env_read=PhysMake(psp->GetEnvironment(),0);
+	do 	{
+		MEM_StrCopy(env_read,env_string,1024);
+		if (!env_string[0]) break;
+		if (!num) { result=env_string;return true;}
+		env_read+=strlen(env_string)+1;
 		num--;
-	}
-	return 0;
+	} while (1);
+	return false;
 }
 
-Bit32u Program::GetEnvCount(void) {
-	char * envstart=(char *)HostMake(psp->GetEnvironment(),0);
-	Bit32u num=0;
-	while (*envstart) {
-		envstart+=strlen(envstart)+1;	
+Bitu Program::GetEnvCount(void) {
+	PhysPt env_read=PhysMake(psp->GetEnvironment(),0);
+	Bitu num=0;
+	while (mem_readb(env_read)!=0) {
+		for (;mem_readb(env_read);env_read++) {};
+		env_read++;
 		num++;
 	}
 	return num;
 }
 
-bool Program::SetEnv(char * env_entry,char * new_string) {
-	MCB * env_mcb=(MCB *)HostMake(psp->GetEnvironment()-1,0);
-	upcase(env_entry);
-	Bit32u env_size=env_mcb->size*16;
-	if (!env_size) E_Exit("SHELL:Illegal environment size");
-	/* First try to find the old entry */
-	size_t len=strlen(env_entry);
-	char * envstart=(char *)HostMake(psp->GetEnvironment(),0);
-	while (*envstart) {
-		if (strncasecmp(env_entry,envstart,len)==0 && envstart[len]=='=') {
-			/* Now remove this entry */
-			memmove(envstart,envstart+strlen(envstart)+1,env_size);
-		} else {
-			envstart+=strlen(envstart)+1;
-			env_size-=(strlen(envstart)+1);
-		}
+bool Program::SetEnv(const char * entry,const char * new_string) {
+	PhysPt env_read=PhysMake(psp->GetEnvironment(),0);
+	PhysPt env_write=env_read;
+	char env_string[1024];
+	do 	{
+		MEM_StrCopy(env_read,env_string,1024);
+		if (!env_string[0]) break;
+		env_read+=strlen(env_string)+1;
+		if (!strchr(env_string,'=')) continue;		/* Remove corrupt entry? */
+		if ((strncasecmp(entry,env_string,strlen(entry))==0) && 
+			env_string[strlen(entry)]=='=') continue;
+		MEM_BlockWrite(env_write,env_string,strlen(env_string)+1);
+		env_write+=strlen(env_string)+1;
+	} while (1);
+/* TODO Maybe save the program name sometime. not really needed though */
+	/* Save the new entry */
+	if (new_string[0]) {
+		sprintf(env_string,"%s=%s",entry,new_string);
+		MEM_BlockWrite(env_write,env_string,strlen(env_string)+1);
+		env_write+=strlen(env_string)+1;
 	}
-	/* Now add the string if there is space available */
-	if (env_size<(strlen(env_entry)+strlen(new_string)+2)) return false;
-	if (!*new_string) return true;
-	sprintf(envstart,"%s=%s",env_entry,new_string);
-	envstart+=strlen(envstart)+1;
-	*envstart++=0;*envstart++=0;*envstart++=0;
+	/* Clear out the final piece of the environment */
+	mem_writed(env_write,0);
 	return true;
 }