diff options
| -rw-r--r-- | ShellPkg/Application/Shell/Shell.c | 142 |
1 files changed, 108 insertions, 34 deletions
diff --git a/ShellPkg/Application/Shell/Shell.c b/ShellPkg/Application/Shell/Shell.c index 2d5c89aadf..ba3be3f6c3 100644 --- a/ShellPkg/Application/Shell/Shell.c +++ b/ShellPkg/Application/Shell/Shell.c @@ -1277,6 +1277,113 @@ ShellConvertAlias( }
/**
+ Parse for the next instance of one string within another string. Can optionally make sure that
+ the string was not escaped (^ character) per the shell specification.
+
+ @param[in] SourceString The string to search within
+ @param[in] FindString The string to look for
+ @param[in] CheckForEscapeCharacter TRUE to skip escaped instances of FinfString, otherwise will return even escaped instances
+**/
+CHAR16*
+EFIAPI
+FindNextInstance(
+ IN CONST CHAR16 *SourceString,
+ IN CONST CHAR16 *FindString,
+ IN CONST BOOLEAN CheckForEscapeCharacter
+ )
+{
+ CHAR16 *Temp;
+ if (SourceString == NULL) {
+ return (NULL);
+ }
+ Temp = StrStr(SourceString, FindString);
+
+ //
+ // If nothing found, or we dont care about escape characters
+ //
+ if (Temp == NULL || !CheckForEscapeCharacter) {
+ return (Temp);
+ }
+
+ //
+ // If we found an escaped character, try again on the remainder of the string
+ //
+ if ((Temp > (SourceString)) && *(Temp-1) == L'^') {
+ return FindNextInstance(Temp+1, FindString, CheckForEscapeCharacter);
+ }
+
+ //
+ // we found the right character
+ //
+ return (Temp);
+}
+
+/**
+ This function will eliminate unreplaced (and therefore non-found) environment variables.
+
+ @param[in,out] CmdLine The command line to update.
+**/
+EFI_STATUS
+EFIAPI
+StripUnreplacedEnvironmentVariables(
+ IN OUT CHAR16 *CmdLine
+ )
+{
+ CHAR16 *FirstPercent;
+ CHAR16 *FirstQuote;
+ CHAR16 *SecondPercent;
+ CHAR16 *SecondQuote;
+ CHAR16 *CurrentLocator;
+
+ for (CurrentLocator = CmdLine ; CurrentLocator != NULL ; ) {
+ FirstQuote = FindNextInstance(CurrentLocator, L"\"", TRUE);
+ FirstPercent = FindNextInstance(CurrentLocator, L"%", TRUE);
+ SecondPercent = FirstPercent!=NULL?FindNextInstance(FirstPercent+1, L"%", TRUE):NULL;
+ if (FirstPercent == NULL || SecondPercent == NULL) {
+ //
+ // If we ever dont have 2 % we are done.
+ //
+ break;
+ }
+
+ if (FirstQuote < FirstPercent) {
+ SecondQuote = FirstQuote!= NULL?FindNextInstance(FirstQuote+1, L"\"", TRUE):NULL;
+ //
+ // Quote is first found
+ //
+
+ if (SecondQuote < FirstPercent) {
+ //
+ // restart after the pair of "
+ //
+ CurrentLocator = SecondQuote + 1;
+ } else /* FirstPercent < SecondQuote */{
+ //
+ // Restart on the first percent
+ //
+ CurrentLocator = FirstPercent;
+ }
+ continue;
+ }
+ ASSERT(FirstPercent < FirstQuote);
+ if (SecondPercent < FirstQuote) {
+ //
+ // We need to remove from FirstPercent to SecondPercent
+ //
+ CopyMem(FirstPercent, SecondPercent + 1, StrSize(SecondPercent + 1));
+
+ //
+ // dont need to update the locator. both % characters are gone.
+ //
+ continue;
+ }
+ ASSERT(FirstQuote < SecondPercent);
+ CurrentLocator = FirstQuote;
+ }
+ return (EFI_SUCCESS);
+}
+
+/**
Function allocates a new command line and replaces all instances of environment
variable names that are correctly preset to their values.
@@ -1298,7 +1405,6 @@ ShellConvertVariables ( CHAR16 *NewCommandLine1;
CHAR16 *NewCommandLine2;
CHAR16 *Temp;
- CHAR16 *Temp2;
UINTN ItemSize;
CHAR16 *ItemTemp;
SCRIPT_FILE *CurrentScriptFile;
@@ -1391,39 +1497,7 @@ ShellConvertVariables ( //
// Remove non-existant environment variables in scripts only
//
- for (Temp = NewCommandLine1 ; Temp != NULL ; ) {
- Temp = StrStr(Temp, L"%");
- if (Temp == NULL) {
- break;
- }
- while (*(Temp - 1) == L'^') {
- Temp = StrStr(Temp + 1, L"%");
- if (Temp == NULL) {
- break;
- }
- }
- if (Temp == NULL) {
- break;
- }
-
- Temp2 = StrStr(Temp + 1, L"%");
- if (Temp2 == NULL) {
- break;
- }
- while (*(Temp2 - 1) == L'^') {
- Temp2 = StrStr(Temp2 + 1, L"%");
- if (Temp2 == NULL) {
- break;
- }
- }
- if (Temp2 == NULL) {
- break;
- }
-
- Temp2++;
- CopyMem(Temp, Temp2, StrSize(Temp2));
- }
-
+ StripUnreplacedEnvironmentVariables(NewCommandLine1);
}
//
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