src/common/win_popen.c

#ifndef lint
static const char RCSid[] = "$Id: win_popen.c,v 1.3 2004/03/28 20:33:12 schorsch Exp $";
#endif
/*
Replacement for the posix popen() on Windows
 
We don't just let the shell do the work like the original.
Since per default there's no decent shell around, we implement
the most basic functionality right here.

currently supports mode "r" and | to chain several processes.
Substrings between matching quotes are considered one word,
ignoring any | within. Quotes don't nest.
 
*/

#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <io.h>     /* _open_osfhandle()  */
#include <fcntl.h>  /* _O_RDONLY          */

#include "paths.h"
#include "rtio.h"
#include "rterror.h"


#define RAD_MAX_PIPES 32 /* maximum number of pipes */

#define R_MODE 1
#define W_MODE 2
#define A_MODE 3

static int parse_pipes(char *s, char *lines[], char **infn, char **outfn,
int *append, int maxl);
static BOOL createPipes(HANDLE*, HANDLE*, HANDLE*, HANDLE*);
static BOOL runChild(char*, char*, HANDLE, HANDLE, HANDLE);
static void resetStdHandles(HANDLE stdoutOrig, HANDLE stdinOrig);
HANDLE newFile(char *fn, int mode);


int
win_pclose(    /* posix pclose replacement */
FILE* p
)
{
        fclose(p);
        /* not sure if it's useful to wait for anything on Windows */
        return 0;
}


FILE *
win_popen(     /* posix popen replacement */
char* command,
char* type
)
{
        char *execfile, *args;
        char *cmdlines[RAD_MAX_PIPES];
        char *infn = NULL, *outfn = NULL;
        char executable[512], estr[512];
        int n, i, mode = 0, append = 0;
        int ncmds = 0;
        FILE *inf = NULL;
        HANDLE stdoutRd = NULL, stdoutWr = NULL;
        HANDLE stdinRd = NULL, stdinWr = NULL;
        HANDLE stderrWr = NULL;
        HANDLE stdoutOrig, stdinOrig;

        if (strchr(type, 'w')) {
                mode = W_MODE;
        } else if (strchr(type, 'r')) {
                mode = R_MODE;
        } else {
                _snprintf(estr, sizeof(estr),
                                "Invalid mode \"%s\" for win_popen().", type);
                eputs(estr);
                return NULL;
        }

        stdoutOrig = GetStdHandle(STD_OUTPUT_HANDLE);
        stdinOrig = GetStdHandle(STD_INPUT_HANDLE);
        /* if we have a console, use it for error output */
        stderrWr = GetStdHandle(STD_ERROR_HANDLE);

        ncmds = parse_pipes(command,cmdlines,&infn,&outfn,&append,RAD_MAX_PIPES);
        if(ncmds <= 0) {
                eputs("Too many pipes or malformed command.");
                goto error;
        }

        if (infn != NULL) {
                stdoutRd = newFile(infn, mode);
        }

        for(n = 0; n < ncmds; ++n) {
                if(!createPipes(&stdoutRd, &stdoutWr,
                        &stdinRd, &stdinWr)) {
                        eputs("Error creating pipe");
                        goto error;
                }
                if (outfn != NULL && n == ncmds - 1) {
                        CloseHandle(stdoutWr);
                        CloseHandle(stdoutRd);
                        stdoutWr = newFile(outfn, mode);
                }
                if (n == 0 && mode == W_MODE) {
                        /* create a standard C file pointer for writing to the input */
                        inf = _fdopen(_open_osfhandle((long)stdinWr, _O_RDONLY), "w");
                }
                /* find the executable on the PATH */
                args = nextword(executable, sizeof(executable), cmdlines[n]);
                if (args == NULL) {
                        eputs("Empty command.");
                        goto error;
                }
                execfile = getpath(executable, getenv("PATH"), X_OK);
                if(execfile == NULL) {
                        _snprintf(estr, sizeof(estr),
                                        "Can't find executable for \"%s\".", executable);
                        eputs(estr);
                        goto error;
                }
                if(!runChild(execfile, cmdlines[n], stdinRd, stdoutWr, stderrWr)) {
                        _snprintf(estr, sizeof(estr),
                                        "Unable to execute executable \"%s\".", executable);
                        eputs(estr);
                        goto error;
                }
                /* close the stdout end just passed to the last process,
                   or the final read will block */
                CloseHandle(stdoutWr);
        }

        /* clean up */
        resetStdHandles(stdinOrig, stdoutOrig);
        for (i = 0; i < ncmds; i++) free(cmdlines[i]);
        if (infn != NULL) free(infn);
        if (outfn != NULL) free(outfn);

        if (mode == R_MODE) {
                /* return a standard C file pointer for reading the output */
                return _fdopen(_open_osfhandle((long)stdoutRd, _O_RDONLY), "r");
        } else if (mode == W_MODE) {
                /* return a standard C file pointer for writing to the input */
                return inf;
        }

error:
        resetStdHandles(stdinOrig, stdoutOrig);
        for (i = 0; i < ncmds; i++) free(cmdlines[i]);
        if (infn != NULL) free(infn);
        if (outfn != NULL) free(outfn);
        return NULL;
}


HANDLE
newFile(char *fn, int mode)
{
        SECURITY_ATTRIBUTES sAttr;
        HANDLE fh;

        sAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
        sAttr.bInheritHandle = TRUE;
        sAttr.lpSecurityDescriptor = NULL;

        if (mode == R_MODE) {
                fh = CreateFile(fn,
                                GENERIC_READ,
                                FILE_SHARE_READ,
                                &sAttr,
                                OPEN_EXISTING,
                                FILE_ATTRIBUTE_NORMAL,
                                NULL);
        } else if (mode == W_MODE || mode == A_MODE) {
                fh = CreateFile(fn,
                                GENERIC_WRITE,
                                FILE_SHARE_WRITE,
                                &sAttr,
                                mode==W_MODE?CREATE_ALWAYS:OPEN_ALWAYS,
                                FILE_ATTRIBUTE_NORMAL,
                                NULL);
        }
        if (fh == NULL) {
                int e = GetLastError();
        }
        return fh;
}


static BOOL
createPipes(       /* establish matching pipes for a subprocess */
HANDLE* stdoutRd,
HANDLE* stdoutWr,
HANDLE* stdinRd,
HANDLE* stdinWr
)
{
        HANDLE stdoutRdInh = NULL;
        HANDLE stdinWrInh = NULL;
        HANDLE curproc;
        SECURITY_ATTRIBUTES sAttr;
        
        curproc = GetCurrentProcess();
        
        /* The rules of inheritance for handles are a mess.
           Just to be safe, make all handles we pass to the
           child processes inheritable */
        sAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
        sAttr.bInheritHandle = TRUE;
        sAttr.lpSecurityDescriptor = NULL;
        
        if(*stdoutRd != NULL){
        /* if we have a previous stdout pipe,
           assign the other end to stdin for the new process */
                CloseHandle(*stdinRd);
                if(!DuplicateHandle(curproc, *stdoutRd,
                        curproc, stdinRd, 0,
                        TRUE, DUPLICATE_SAME_ACCESS))
                        return FALSE;
                CloseHandle(*stdoutRd);
                if(!SetStdHandle(STD_INPUT_HANDLE, *stdinRd))
                        return FALSE;
        } else {
                /* there's no previous stdout, create a new stdin pipe */
                if(!CreatePipe(stdinRd, &stdinWrInh, &sAttr, 0))
                        return FALSE;
                if(!SetStdHandle(STD_INPUT_HANDLE, *stdinRd))
                        return FALSE;
                CloseHandle(stdinWrInh);
        }
        
        /* create the stdout pipe for the new process */
        if(!CreatePipe(&stdoutRdInh, stdoutWr, &sAttr, 0))
                return FALSE;
        if(!SetStdHandle(STD_OUTPUT_HANDLE, *stdoutWr))
                return FALSE;
        if(!DuplicateHandle(curproc, stdoutRdInh,
                curproc, stdoutRd, 0,
                FALSE, DUPLICATE_SAME_ACCESS))
                return FALSE;
        CloseHandle(stdoutRdInh);
        
        return TRUE;
}


static void
resetStdHandles(    /* clean up our std streams */
HANDLE stdoutOrig,
HANDLE stdinOrig
)
{
        SetStdHandle(STD_OUTPUT_HANDLE, stdoutOrig);
        SetStdHandle(STD_INPUT_HANDLE, stdinOrig);
}


static int
parse_pipes(     /* split a shell command pipe sequence */
char *s,
char *lines[],
char **infn,
char **outfn,
int *append,
int maxl
)
{
        int n = 0, i;
        char *se, *ws;
        char *curs;
        int llen = 0;
        int quote = 0;
        int last = 0;

        if (maxl<= 0) return 0;
        if (s == NULL) {
                return 0;
        }
        *infn = *outfn = NULL;
        while (isspace(*s)) s++; /* leading whitespace */
        se = s;
        while (n < maxl) {
                switch (*se) {
                        case '"':
                                if (quote == '"') quote = 0;
                                else if (quote == 0) quote = '"';
                                break;
                        case '\'':
                                if (quote == '\'') quote = 0;
                                else if (quote == 0) quote = '\'';
                                break;
                        case '<':
                        case '>':
                        case '|':
                        case '\0':
                                if (*se != '\0' && quote)
                                        break;
                                llen = se - s;
                                curs = malloc(llen+1);
                                strncpy(curs, s, llen);
                                /* remove unix style line-end escapes */
                                while((ws = strstr(curs, "\\\n")) != NULL)
                                        *ws = *(ws+1) = ' ';
                                /* remove DOS style line-end escapes */
                                while((ws = strstr(curs, "\\\r\n")) != NULL)
                                        *ws = *(ws+1) = *(ws+2) = ' ';
                                while (isspace(*(curs + llen - 1)))
                                        llen--; /* trailing whitespace */
                                curs[llen] = '\0';

                                if (last == '|' || last == 0) { /* first or pipe */
                                        lines[n] = curs;
                                        n++;
                                        curs = NULL;
                                } else if (last == '<') { /* input file */
                                        if (*infn != NULL) {
                                                eputs("win_popen(): ambiguous input redirection");
                                                goto error;
                                        }
                                        *infn = curs;
                                        curs = NULL;
                                } else if (last == '>') { /* output file */
                                        if (*outfn != NULL) {
                                                eputs("win_popen(): ambiguous output redirection");
                                                goto error;
                                        }
                                        *outfn = curs;
                                        curs = NULL;
                                        if (*se != '\0' && *se+1 == '>') { /* >> */
                                                *append = 1;
                                                se++;
                                        }
                                }
                                last = *se;

                                if (*se == '\0') return n;
                                s = se + 1;
                                while (isspace(*s)) s++; /* leading whitespace */
                                se = s;
                                break;
                        default:
                                break;
                }
                se++;
        }
        /* more jobs than slots */
error:
        for (i = 0; i < n; i++) free(lines[i]);
        if (*infn != NULL) free(*infn);
        if (*outfn != NULL) free(*outfn);
        if (curs != NULL) free(curs);
        return -1;
}


static BOOL
runChild(         /* start a child process with the right std streams */
char* executable,
char* cmdline,
HANDLE stdinRd,
HANDLE stdoutWr,
HANDLE stderrWr
)
{
        PROCESS_INFORMATION procInfo;
        STARTUPINFO startupInfo;

        /* use the given handles and don't display the console window */
        ZeroMemory(&startupInfo, sizeof(STARTUPINFO));
        startupInfo.cb = sizeof(STARTUPINFO);
        startupInfo.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW;
        startupInfo.wShowWindow = SW_HIDE;
        startupInfo.hStdInput = stdinRd;
        startupInfo.hStdOutput = stdoutWr;
        startupInfo.hStdError = stderrWr;

        return CreateProcess(executable, cmdline, NULL, NULL,
                TRUE, 0,
                NULL, NULL, &startupInfo, &procInfo);
}


Revision:	1.4
Committed:	Mon Oct 4 10:14:22 2004 UTC (21 years, 1 month ago) by schorsch
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R7P2, rad3R7P1, rad4R0, rad3R6, rad3R6P1, rad3R8, rad3R9
Changes since 1.3:	+3 -2 lines
Log Message:	Included paths.h for X_OK.
#	User	Rev	Content
1	schorsch	1.1	#ifndef lint
2	schorsch	1.4	static const char RCSid[] = "$Id: win_popen.c,v 1.3 2004/03/28 20:33:12 schorsch Exp $";
3	schorsch	1.1	#endif
4			/*
5			Replacement for the posix popen() on Windows
6
7			We don't just let the shell do the work like the original.
8			Since per default there's no decent shell around, we implement
9			the most basic functionality right here.
10
11			currently supports mode "r" and \| to chain several processes.
12			Substrings between matching quotes are considered one word,
13			ignoring any \| within. Quotes don't nest.
14
15			*/
16
17			#include <windows.h>
18			#include <stdlib.h>
19			#include <stdio.h>
20			#include <string.h>
21			#include <ctype.h>
22			#include <io.h> /* _open_osfhandle() */
23			#include <fcntl.h> /* _O_RDONLY */
24
25	schorsch	1.4	#include "paths.h"
26	schorsch	1.1	#include "rtio.h"
27			#include "rterror.h"
28
29
30			#define RAD_MAX_PIPES 32 /* maximum number of pipes */
31
32	schorsch	1.3	#define R_MODE 1
33			#define W_MODE 2
34			#define A_MODE 3
35
36			static int parse_pipes(char s, char lines[], char infn, char outfn,
37			int *append, int maxl);
38	schorsch	1.1	static BOOL createPipes(HANDLE, HANDLE, HANDLE, HANDLE);
39			static BOOL runChild(char, char, HANDLE, HANDLE, HANDLE);
40			static void resetStdHandles(HANDLE stdoutOrig, HANDLE stdinOrig);
41	schorsch	1.3	HANDLE newFile(char *fn, int mode);
42	schorsch	1.1
43
44			int
45	schorsch	1.2	win_pclose( /* posix pclose replacement */
46	schorsch	1.1	FILE* p
47			)
48			{
49			fclose(p);
50			/* not sure if it's useful to wait for anything on Windows */
51			return 0;
52			}
53
54
55			FILE *
56	schorsch	1.2	win_popen( /* posix popen replacement */
57	schorsch	1.1	char* command,
58			char* type
59			)
60			{
61			char execfile, args;
62			char *cmdlines[RAD_MAX_PIPES];
63	schorsch	1.3	char infn = NULL, outfn = NULL;
64			char executable[512], estr[512];
65			int n, i, mode = 0, append = 0;
66	schorsch	1.1	int ncmds = 0;
67	schorsch	1.3	FILE *inf = NULL;
68	schorsch	1.1	HANDLE stdoutRd = NULL, stdoutWr = NULL;
69			HANDLE stdinRd = NULL, stdinWr = NULL;
70			HANDLE stderrWr = NULL;
71			HANDLE stdoutOrig, stdinOrig;
72
73	schorsch	1.3	if (strchr(type, 'w')) {
74			mode = W_MODE;
75			} else if (strchr(type, 'r')) {
76			mode = R_MODE;
77			} else {
78			_snprintf(estr, sizeof(estr),
79			"Invalid mode \"%s\" for win_popen().", type);
80			eputs(estr);
81			return NULL;
82			}
83
84	schorsch	1.1	stdoutOrig = GetStdHandle(STD_OUTPUT_HANDLE);
85			stdinOrig = GetStdHandle(STD_INPUT_HANDLE);
86			/* if we have a console, use it for error output */
87			stderrWr = GetStdHandle(STD_ERROR_HANDLE);
88
89	schorsch	1.3	ncmds = parse_pipes(command,cmdlines,&infn,&outfn,&append,RAD_MAX_PIPES);
90			if(ncmds <= 0) {
91	schorsch	1.1	eputs("Too many pipes or malformed command.");
92			goto error;
93			}
94
95	schorsch	1.3	if (infn != NULL) {
96			stdoutRd = newFile(infn, mode);
97			}
98
99	schorsch	1.1	for(n = 0; n < ncmds; ++n) {
100			if(!createPipes(&stdoutRd, &stdoutWr,
101			&stdinRd, &stdinWr)) {
102			eputs("Error creating pipe");
103			goto error;
104			}
105	schorsch	1.3	if (outfn != NULL && n == ncmds - 1) {
106			CloseHandle(stdoutWr);
107			CloseHandle(stdoutRd);
108			stdoutWr = newFile(outfn, mode);
109			}
110			if (n == 0 && mode == W_MODE) {
111			/* create a standard C file pointer for writing to the input */
112			inf = _fdopen(_open_osfhandle((long)stdinWr, _O_RDONLY), "w");
113			}
114	schorsch	1.1	/* find the executable on the PATH */
115			args = nextword(executable, sizeof(executable), cmdlines[n]);
116			if (args == NULL) {
117			eputs("Empty command.");
118			goto error;
119			}
120			execfile = getpath(executable, getenv("PATH"), X_OK);
121			if(execfile == NULL) {
122			_snprintf(estr, sizeof(estr),
123			"Can't find executable for \"%s\".", executable);
124			eputs(estr);
125			goto error;
126			}
127			if(!runChild(execfile, cmdlines[n], stdinRd, stdoutWr, stderrWr)) {
128			_snprintf(estr, sizeof(estr),
129			"Unable to execute executable \"%s\".", executable);
130			eputs(estr);
131			goto error;
132			}
133			/* close the stdout end just passed to the last process,
134			or the final read will block */
135			CloseHandle(stdoutWr);
136			}
137	schorsch	1.3
138	schorsch	1.1	/* clean up */
139			resetStdHandles(stdinOrig, stdoutOrig);
140			for (i = 0; i < ncmds; i++) free(cmdlines[i]);
141	schorsch	1.3	if (infn != NULL) free(infn);
142			if (outfn != NULL) free(outfn);
143	schorsch	1.1
144	schorsch	1.3	if (mode == R_MODE) {
145			/* return a standard C file pointer for reading the output */
146			return _fdopen(_open_osfhandle((long)stdoutRd, _O_RDONLY), "r");
147			} else if (mode == W_MODE) {
148			/* return a standard C file pointer for writing to the input */
149			return inf;
150			}
151	schorsch	1.1
152			error:
153			resetStdHandles(stdinOrig, stdoutOrig);
154			for (i = 0; i < ncmds; i++) free(cmdlines[i]);
155	schorsch	1.3	if (infn != NULL) free(infn);
156			if (outfn != NULL) free(outfn);
157	schorsch	1.1	return NULL;
158			}
159
160
161	schorsch	1.3	HANDLE
162			newFile(char *fn, int mode)
163			{
164			SECURITY_ATTRIBUTES sAttr;
165			HANDLE fh;
166
167			sAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
168			sAttr.bInheritHandle = TRUE;
169			sAttr.lpSecurityDescriptor = NULL;
170
171			if (mode == R_MODE) {
172			fh = CreateFile(fn,
173			GENERIC_READ,
174			FILE_SHARE_READ,
175			&sAttr,
176			OPEN_EXISTING,
177			FILE_ATTRIBUTE_NORMAL,
178			NULL);
179			} else if (mode == W_MODE \|\| mode == A_MODE) {
180			fh = CreateFile(fn,
181			GENERIC_WRITE,
182			FILE_SHARE_WRITE,
183			&sAttr,
184			mode==W_MODE?CREATE_ALWAYS:OPEN_ALWAYS,
185			FILE_ATTRIBUTE_NORMAL,
186			NULL);
187			}
188			if (fh == NULL) {
189			int e = GetLastError();
190			}
191			return fh;
192			}
193
194
195	schorsch	1.1	static BOOL
196			createPipes( /* establish matching pipes for a subprocess */
197			HANDLE* stdoutRd,
198			HANDLE* stdoutWr,
199			HANDLE* stdinRd,
200			HANDLE* stdinWr
201			)
202			{
203			HANDLE stdoutRdInh = NULL;
204			HANDLE stdinWrInh = NULL;
205			HANDLE curproc;
206			SECURITY_ATTRIBUTES sAttr;
207
208			curproc = GetCurrentProcess();
209
210			/* The rules of inheritance for handles are a mess.
211			Just to be safe, make all handles we pass to the
212			child processes inheritable */
213			sAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
214			sAttr.bInheritHandle = TRUE;
215			sAttr.lpSecurityDescriptor = NULL;
216
217			if(*stdoutRd != NULL){
218			/* if we have a previous stdout pipe,
219			assign the other end to stdin for the new process */
220			CloseHandle(*stdinRd);
221			if(!DuplicateHandle(curproc, *stdoutRd,
222			curproc, stdinRd, 0,
223			TRUE, DUPLICATE_SAME_ACCESS))
224			return FALSE;
225			CloseHandle(*stdoutRd);
226			if(!SetStdHandle(STD_INPUT_HANDLE, *stdinRd))
227			return FALSE;
228			} else {
229			/* there's no previous stdout, create a new stdin pipe */
230			if(!CreatePipe(stdinRd, &stdinWrInh, &sAttr, 0))
231			return FALSE;
232			if(!SetStdHandle(STD_INPUT_HANDLE, *stdinRd))
233			return FALSE;
234			CloseHandle(stdinWrInh);
235			}
236
237			/* create the stdout pipe for the new process */
238			if(!CreatePipe(&stdoutRdInh, stdoutWr, &sAttr, 0))
239			return FALSE;
240			if(!SetStdHandle(STD_OUTPUT_HANDLE, *stdoutWr))
241			return FALSE;
242			if(!DuplicateHandle(curproc, stdoutRdInh,
243			curproc, stdoutRd, 0,
244			FALSE, DUPLICATE_SAME_ACCESS))
245			return FALSE;
246			CloseHandle(stdoutRdInh);
247
248			return TRUE;
249			}
250
251
252			static void
253			resetStdHandles( /* clean up our std streams */
254			HANDLE stdoutOrig,
255			HANDLE stdinOrig
256			)
257			{
258			SetStdHandle(STD_OUTPUT_HANDLE, stdoutOrig);
259			SetStdHandle(STD_INPUT_HANDLE, stdinOrig);
260			}
261
262
263			static int
264			parse_pipes( /* split a shell command pipe sequence */
265	schorsch	1.3	char *s,
266			char *lines[],
267			char **infn,
268			char **outfn,
269			int *append,
270	schorsch	1.1	int maxl
271			)
272			{
273			int n = 0, i;
274			char se, ws;
275	schorsch	1.3	char *curs;
276	schorsch	1.1	int llen = 0;
277			int quote = 0;
278	schorsch	1.3	int last = 0;
279	schorsch	1.1
280			if (maxl<= 0) return 0;
281			if (s == NULL) {
282			return 0;
283			}
284	schorsch	1.3	infn = outfn = NULL;
285	schorsch	1.1	while (isspace(s)) s++; / leading whitespace */
286			se = s;
287			while (n < maxl) {
288			switch (*se) {
289			case '"':
290			if (quote == '"') quote = 0;
291			else if (quote == 0) quote = '"';
292			break;
293			case '\'':
294			if (quote == '\'') quote = 0;
295			else if (quote == 0) quote = '\'';
296			break;
297	schorsch	1.3	case '<':
298			case '>':
299	schorsch	1.1	case '\|':
300			case '\0':
301	schorsch	1.3	if (*se != '\0' && quote)
302	schorsch	1.1	break;
303			llen = se - s;
304	schorsch	1.3	curs = malloc(llen+1);
305			strncpy(curs, s, llen);
306	schorsch	1.1	/* remove unix style line-end escapes */
307	schorsch	1.3	while((ws = strstr(curs, "\\\n")) != NULL)
308	schorsch	1.1	ws = (ws+1) = ' ';
309			/* remove DOS style line-end escapes */
310	schorsch	1.3	while((ws = strstr(curs, "\\\r\n")) != NULL)
311	schorsch	1.1	ws = (ws+1) = *(ws+2) = ' ';
312	schorsch	1.3	while (isspace(*(curs + llen - 1)))
313	schorsch	1.1	llen--; /* trailing whitespace */
314	schorsch	1.3	curs[llen] = '\0';
315
316			if (last == '\|' \|\| last == 0) { /* first or pipe */
317			lines[n] = curs;
318			n++;
319			curs = NULL;
320			} else if (last == '<') { /* input file */
321			if (*infn != NULL) {
322			eputs("win_popen(): ambiguous input redirection");
323			goto error;
324			}
325			*infn = curs;
326			curs = NULL;
327			} else if (last == '>') { /* output file */
328			if (*outfn != NULL) {
329	schorsch	1.4	eputs("win_popen(): ambiguous output redirection");
330	schorsch	1.3	goto error;
331			}
332			*outfn = curs;
333			curs = NULL;
334			if (se != '\0' && se+1 == '>') { /* >> */
335			*append = 1;
336			se++;
337			}
338			}
339			last = *se;
340
341	schorsch	1.1	if (*se == '\0') return n;
342			s = se + 1;
343			while (isspace(s)) s++; / leading whitespace */
344			se = s;
345			break;
346			default:
347			break;
348			}
349			se++;
350			}
351			/* more jobs than slots */
352	schorsch	1.3	error:
353	schorsch	1.1	for (i = 0; i < n; i++) free(lines[i]);
354	schorsch	1.3	if (infn != NULL) free(infn);
355			if (outfn != NULL) free(outfn);
356			if (curs != NULL) free(curs);
357	schorsch	1.1	return -1;
358			}
359
360
361			static BOOL
362			runChild( /* start a child process with the right std streams */
363			char* executable,
364			char* cmdline,
365			HANDLE stdinRd,
366			HANDLE stdoutWr,
367			HANDLE stderrWr
368			)
369			{
370			PROCESS_INFORMATION procInfo;
371			STARTUPINFO startupInfo;
372
373			/* use the given handles and don't display the console window */
374			ZeroMemory(&startupInfo, sizeof(STARTUPINFO));
375			startupInfo.cb = sizeof(STARTUPINFO);
376			startupInfo.dwFlags = STARTF_USESTDHANDLES \| STARTF_USESHOWWINDOW;
377			startupInfo.wShowWindow = SW_HIDE;
378			startupInfo.hStdInput = stdinRd;
379			startupInfo.hStdOutput = stdoutWr;
380			startupInfo.hStdError = stderrWr;
381
382			return CreateProcess(executable, cmdline, NULL, NULL,
383			TRUE, 0,
384			NULL, NULL, &startupInfo, &procInfo);
385			}
386
387
388