1) strip ^ escapes from text before processing set command 2) recursive descent implementation of set /a - should fix bug 728 (In case anyone checks I realized there were some gaping holes in the implementation I posted to the ml, so this one is modified from it. This code could stand to benefit from a comprehensive feature/regression test.) Modified: trunk/reactos/subsys/system/cmd/set.c _____
Modified: trunk/reactos/subsys/system/cmd/set.c --- trunk/reactos/subsys/system/cmd/set.c 2005-09-18 03:26:52 UTC (rev 17905) +++ trunk/reactos/subsys/system/cmd/set.c 2005-09-18 03:52:34 UTC (rev 17906) @@ -35,6 +35,8 @@
*/
#include <precomp.h> +#include <malloc.h> +#include <stdio.h> #include "resource.h"
#ifdef INCLUDE_CMD_SET @@ -43,18 +45,35 @@ /* initial size of environment variable buffer */ #define ENV_BUFFER_SIZE 1024
+static BOOL +seta_eval ( LPCTSTR expr );
+static LPCTSTR +skip_ws ( LPCTSTR p ) +{ + return p + strspn ( p, " \t" ); +} + INT cmd_set (LPTSTR cmd, LPTSTR param) { TCHAR szMsg[RC_STRING_MAX_SIZE]; + INT i; LPTSTR p;
- if (!_tcsncmp (param, _T("/?"), 2)) + if ( !_tcsncmp (param, _T("/?"), 2) ) { ConOutResPaging(TRUE,STRING_SET_HELP); return 0; }
+ /* remove escapes */ + if ( param[0] ) for ( i = 0; param[i+1]; i++ ) + { + if ( param[i] == '^' && strchr("<|>",param[i+1]) ) + { + memmove ( ¶m[i], ¶m[i+1], _tcslen(¶m[i]) * sizeof(TCHAR) ); + } + }
/* if no parameters, show the environment */ if (param[0] == _T('\0')) @@ -83,6 +102,12 @@ return 0; }
+ if ( !_tcsnicmp (param, _T("/A"), 2) ) + { + // TODO FIXME - what are we supposed to return? + return seta_eval ( skip_ws(param+2) ); + } + p = _tcschr (param, _T('=')); if (p) { @@ -124,4 +149,404 @@ return 0; }
+static INT +ident_len ( LPCTSTR p ) +{ + LPCTSTR p2 = p; + if ( __iscsymf(*p) ) + { + ++p2; + while ( __iscsym(*p2) ) + ++p2; + } + return p2-p; +} + +#define PARSE_IDENT(ident,identlen,p) \ + identlen = ident_len(p); \ + ident = (LPTSTR)alloca ( ( identlen + 1 ) * sizeof(TCHAR) ); \ + memmove ( ident, p, identlen * sizeof(TCHAR) ); \ + ident[identlen] = 0; \ + p += identlen; + +static BOOL +seta_identval ( LPCTSTR ident, INT* result ) +{ + // get size of buffer for env var + LPTSTR buf; + DWORD dwBuffer = GetEnvironmentVariable ( ident, NULL, 0 ); + // if GetEnvironmentVariable() fails, it returns 0 + if ( !dwBuffer ) + { + // TODO FIXME - is it correct to report a value of 0 for non-existant variables? + *result = 0; + return FALSE; + } + buf = (LPTSTR)alloca ( dwBuffer * sizeof(TCHAR) ); + if ( !buf ) + { + // TODO FIXME - is it correct to report 0 when report resources low... should we error somehow? + *result = 0; + return FALSE; + } + GetEnvironmentVariable ( ident, buf, dwBuffer ); + *result = atoi ( buf ); + return TRUE; +} + +static BOOL +calc ( INT* lval, TCHAR op, INT rval ) +{ + switch ( op ) + { + case '*': + *lval *= rval; + break; + case '/': + *lval /= rval; + break; + case '%': + *lval %= rval; + break; + case '+': + *lval += rval; + break; + case '-': + *lval -= rval; + break; + case '&': + *lval &= rval; + break; + case '^': + *lval ^= rval; + break; + case '|': + *lval |= rval; + break; + default: + printf ( "Invalid operand.\n" ); + return FALSE; + } + return TRUE; +} + +static BOOL +seta_stmt ( LPCTSTR* p_, INT* result ); + +static BOOL +seta_unaryTerm ( LPCTSTR* p_, INT* result ) +{ + LPCTSTR p = *p_; + if ( *p == '(' ) + { + INT rval; + p = skip_ws ( p + 1 ); + if ( !seta_stmt ( &p, &rval ) ) + return FALSE; + if ( *p != ')' ) + { + _tprintf ( _T("Expected ')'\n") ); + return FALSE; + } + *result = rval; + p = skip_ws ( p + 1 ); + } + else if ( isdigit(*p) ) + { + *result = atoi ( p ); + p = skip_ws ( p + strspn ( p, "1234567890" ) ); + } + else if ( __iscsymf(*p) ) + { + LPTSTR ident; + INT identlen; + PARSE_IDENT(ident,identlen,p); + if ( !seta_identval ( ident, result ) ) + return FALSE; + } + else + { + _tprintf ( _T("Expected number or variable name\n") ); + return FALSE; + } + *p_ = p; + return TRUE; +} + +static BOOL +seta_mulTerm ( LPCTSTR* p_, INT* result ) +{ + LPCTSTR p = *p_; + TCHAR op = 0; + INT rval; + if ( _tcschr(_T("!~-"),*p) ) + { + op = *p; + p = skip_ws ( p + 1 ); + } + if ( !seta_unaryTerm ( &p, &rval ) ) + return FALSE; + switch ( op ) + { + case '!': + rval = !rval; + break; + case '~': + rval = ~rval; + break; + case '-': + rval = -rval; + break; + } + + *result = rval; + *p_ = p; + return TRUE; +} + +static BOOL +seta_addTerm ( LPCTSTR* p_, INT* result ) +{ + LPCTSTR p = *p_; + INT lval; + if ( !seta_mulTerm ( &p, &lval ) ) + return FALSE; + while ( *p && _tcschr(_T("*/%"),*p) ) + { + INT rval; + TCHAR op = *p; + + p = skip_ws ( p+1 ); + + if ( !seta_mulTerm ( &p, &rval ) ) + return FALSE; + + if ( !calc ( &lval, op, rval ) ) + return FALSE; + } + + *result = lval; + *p_ = p; + return TRUE; +} + +static BOOL +seta_logShiftTerm ( LPCTSTR* p_, INT* result ) +{ + LPCTSTR p = *p_; + INT lval; + if ( !seta_addTerm ( &p, &lval ) ) + return FALSE; + while ( *p && _tcschr(_T("+-"),*p) ) + { + INT rval; + TCHAR op = *p; + + p = skip_ws ( p+1 ); + + if ( !seta_addTerm ( &p, &rval ) ) + return FALSE; + + if ( !calc ( &lval, op, rval ) ) + return FALSE; + } + + *result = lval; + *p_ = p; + return TRUE; +} + +static BOOL +seta_bitAndTerm ( LPCTSTR* p_, INT* result ) +{ + LPCTSTR p = *p_; + INT lval; + if ( !seta_logShiftTerm ( &p, &lval ) ) + return FALSE; + while ( *p && _tcschr(_T("<>"),*p) && p[0] == p[1] ) + { + INT rval; + TCHAR op = *p; + + p = skip_ws ( p+2 ); + + if ( !seta_logShiftTerm ( &p, &rval ) ) + return FALSE; + + if ( !calc ( &lval, op, rval ) ) + return FALSE; + } + + *result = lval; + *p_ = p; + return TRUE; +} + +static BOOL +seta_bitExclOrTerm ( LPCTSTR* p_, INT* result ) +{ + LPCTSTR p = *p_; + INT lval; + if ( !seta_bitAndTerm ( &p, &lval ) ) + return FALSE; + while ( *p == _T('&') ) + { + INT rval; + + p = skip_ws ( p+1 ); + + if ( !seta_bitAndTerm ( &p, &rval ) ) + return FALSE; + + lval &= rval; + } + + *result = lval; + *p_ = p; + return TRUE; +} + +static BOOL +seta_bitOrTerm ( LPCTSTR* p_, INT* result ) +{ + LPCTSTR p = *p_; + INT lval; + if ( !seta_bitExclOrTerm ( &p, &lval ) ) + return FALSE; + while ( *p == _T('^') ) + { + INT rval; + + p = skip_ws ( p+1 ); + + if ( !seta_bitExclOrTerm ( &p, &rval ) ) + return FALSE; + + lval ^= rval; + } + + *result = lval; + *p_ = p; + return TRUE; +} + +static BOOL +seta_expr ( LPCTSTR* p_, INT* result ) +{ + LPCTSTR p = *p_; + INT lval; + if ( !seta_bitOrTerm ( &p, &lval ) ) + return FALSE; + while ( *p == _T('|') ) + { + INT rval; + + p = skip_ws ( p+1 ); + + if ( !seta_bitOrTerm ( &p, &rval ) ) + return FALSE; + + lval |= rval; + } + + *result = lval; + *p_ = p; + return TRUE; +} + +static BOOL +seta_assignment ( LPCTSTR* p_, INT* result ) +{ + LPCTSTR p = *p_; + LPTSTR ident; + TCHAR op = 0; + INT identlen, exprval; + + PARSE_IDENT(ident,identlen,p); + if ( identlen ) + { + if ( *p == _T('=') ) + op = *p, p++; + else if ( _tcschr ( _T("*/%+-&^|"), *p ) && p[1] == _T('=') ) + op = *p, p += 2; + else if ( _tcschr ( _T("<>"), *p ) && *p == p[1] && p[2] == _T('=') ) + op = *p, p += 3; + else + { + _tprintf ( _T("Missing operand.\n") ); + return FALSE; + } + p = skip_ws ( p ); + } + + /* allow to chain multiple assignments, such as: a=b=1 */ + if ( ident && op ) + { + if ( !seta_assignment ( &p, &exprval ) ) + return FALSE; + } + else + { + if ( !seta_expr ( &p, &exprval ) ) + return FALSE; + } + + if ( identlen ) + { + INT identval; + LPTSTR buf; + + if ( !seta_identval ( ident, &identval ) ) + identval = 0; + if ( op == '=' ) + identval = exprval; + else if ( !calc ( &identval, op, exprval ) ) + return FALSE; + buf = (LPTSTR)alloca ( 32 * sizeof(TCHAR) ); + _sntprintf ( buf, 32, _T("%i"), identval ); + SetEnvironmentVariable ( ident, buf ); // TODO FIXME - check return value + exprval = identval; + } + + *result = exprval; + *p_ = p; + return TRUE; +} + +static BOOL +seta_stmt ( LPCTSTR* p_, INT* result ) +{ + LPCTSTR p = *p_; + INT rval; + + if ( !seta_assignment ( &p, &rval ) ) + return FALSE; + while ( *p == _T(',') ) + { + p = skip_ws ( p+1 ); + + if ( !seta_assignment ( &p, &rval ) ) + return FALSE; + } + + *result = rval; + *p_ = p; + return TRUE; +} + +static BOOL +seta_eval ( LPCTSTR p ) +{ + INT rval; + if ( !*p ) + { + _tprintf ( _T("The syntax of the command is incorrect.\n") ); + return FALSE; + } + if ( !seta_stmt ( &p, &rval ) ) + return FALSE; + _tprintf ( _T("%i\n"), rval ); + return TRUE; +} + #endif
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