source: trunk/src/win32k/misc/env.c@ 3453

Last change on this file since 3453 was 3412, checked in by bird, 26 years ago

Much of the coding is done. But will have to select/change strategy for
getting the environment data soon.
File size: 6.1 KB
Line 
1/* $Id: env.c,v 1.2 2000-04-17 02:26:04 bird Exp $
2 *
3 * Environment access functions
4 *
5 * Copyright (c) 2000 knut st. osmundsen (knut.stange.osmundsen@pmsc.no)
6 *
7 * Project Odin Software License can be found in LICENSE.TXT
8 *
9 */
10
11/*******************************************************************************
12* Defined Constants And Macros *
13*******************************************************************************/
14#define INCL_DOSERRORS /* Error codes */
15#define INCL_OS2KRNL_VM /* OS2KRNL: Virtual Memory Management */
16
17
18/*******************************************************************************
19* Header Files *
20*******************************************************************************/
21#include <os2.h>
22
23#include "dev32.h"
24#include "dev32hlp.h"
25#include "log.h"
26#include "ptda.h"
27#include "OS2Krnl.h"
28#include <string.h>
29
30#include "env.h"
31
32
33/**
34 * Scans the given environment data for a given environment variable and returns
35 * its value if found.
36 * @returns Pointer to environment variable value for the variable given in
37 * pszVar.
38 * If the variable wasn't found NULL is returned.
39 * @param paszEnv Pointer to the environment data to search.
40 * The environment data is a list of zero-strings terminated
41 * by an empty string. The strings are paired, that means
42 * that the first string is the variable name and the
43 * following string is the value of the variable.
44 * AFAIK a variable can't have an empty value string!
45 * @param pszVar Name of the environment variable to find.
46 */
47const char *ScanEnv(const char *paszEnv, const char *pszVar)
48{
49 /*
50 * Loop thru the environment data until an empty string is reached.
51 */
52 while (*paszEnv != '\0')
53 {
54 register int i; /* Variable use to store the compare result. */
55
56 /*
57 * Variable name.
58 * Check if it's matching the name we're searching for and skip the variable name.
59 */
60 i = stricmp(paszEnv, pszVar);
61 paszEnv += strlen(paszEnv) + 1;
62 if (i == 0)
63 { /* Variable was found. Return pointer to the value. */
64 return paszEnv;
65 }
66
67 /*
68 * !Paranoia!
69 * If no value string we'll quit. This may be an IPE, if not it might
70 * cause one if we continue processing the environment data.
71 */
72 if (*paszEnv == '\0')
73 break;
74
75 /* Skip value */
76 paszEnv += strlen(paszEnv) + 1;
77 }
78
79 return NULL;
80}
81
82
83/**
84 * Get the linear pointer to the environment data.
85 *
86 * @returns Pointer to environment data.
87 * NULL on failure.
88 */
89const char *GetEnv(void)
90{
91 /* There is probably two ways of getting the environment data for a the
92 * current process: 1) get it from the PTDA->ptda_environ
93 * 2) Local infosegment (LIS from GetDosVar devhlp)
94 * I am not sure which one of these works best. What I know is that
95 * method 1) is used by the w_GetEnv API worker. This API is called at
96 * Ring-0 from some delete file operation. (Which uses it to get the
97 * DELETEDIR environment variable.) The w_GetEnv API worker is 16-bit
98 * I don't want to thunk around using that. There for I'll implement
99 * my own GetEnv. So, currently I'll write the code for both 1) and
100 * 2), testing will show which one of them are most handy.
101 */
102
103 #if 1
104 PPTDA pPTDACur; /* Pointer to the current (system context) PTDA */
105 PPTDA pPTDA; /* PTDA in question. */
106 USHORT hobEnviron; /* Object handle of the environ block */
107 APIRET rc; /* Return from VMObjHandleInfo. */
108 USHORT ushPTDA; /* Handle of the context PTDA. (VMObjH..) */
109 ULONG ulAddr = 0; /* Address of the environment data. */
110
111 /*
112 * Use PTDA (1):
113 * Get the current PTDA. (Fail if this call failes.)
114 * IF pPTDAExecChild isn't NULL THEN try get environment for that first.
115 * IF failed or no pPTDAExecChild THEN try get environment from pPTDA.
116 */
117 pPTDACur = ptdaGetCur();
118 if (pPTDA != NULL)
119 {
120 pPTDA = ptdaGet_pPTDAExecChild(pPTDA);
121 if (pPTDA != NULL)
122 {
123 hobEnviron = ptdaGet_ptda_environ(pPTDA);
124 if (hobEnviron != 0)
125 {
126 rc = VMObjHandleInfo(hobEnviron, SSToDS(&ulAddr), SSToDS(&ushPTDA));
127 if (rc == NO_ERROR)
128 return (const char *)ulAddr;
129 kprintf(("GetEnv: VMObjHandleInfo failed with rc=%d for hob=0x%04x\n", rc, hobEnviron));
130 }
131 }
132
133 hobEnviron = ptdaGet_ptda_environ(pPTDACur);
134 if (hobEnviron != 0)
135 {
136 rc = VMObjHandleInfo(hobEnviron, SSToDS(&ulAddr), SSToDS(&ushPTDA));
137 if (rc != NO_ERROR)
138 {
139 kprintf(("GetEnv: VMObjHandleInfo failed with rc=%d for hob=0x%04x\n", rc, hobEnviron));
140 }
141 }
142 }
143 else
144 {
145 kprintf(("GetEnv: Failed to get current PTDA.\n"));
146 }
147
148 return (const char *)ulAddr;
149
150 #else
151
152 struct InfoSegLDT * pLIS; /* Pointer to local infosegment. */
153 PVOID pv; /* Address to return. */
154
155
156 /*
157 * Use LocalInfoSegment (2)
158 * Get the LIS using Dh32_GetDosVar
159 */
160 pLIS = (struct InfoSegLDT*)D32Hlp_GetDOSVar(DHGETDOSV_LOCINFOSEG, 0);
161 if (pLIS == NULL)
162 {
163 kprintf(("GetEnv: Failed to get local info segment\n"));
164 return NULL;
165 }
166
167 if (pLIS->LIS_AX <= 3)
168 {
169 kprintf(("GetEnv: environment selector is %d, ie. NULL\n", pLIS->LIS_AX));
170 return NULL;
171 }
172
173 pv = D32Hlp_VirtToLin2(pLIS->LIS_AX, 0);
174 if (pv != NULL)
175 {
176 kprintf(("GetEnv: VirtToLin2 failed to thunk %04x:0000 to linar address\n", pLIS->LIS_AX));
177 }
178 return (const char *)pv;
179 #endif
180}
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