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#ifndef lint |
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static const char RCSid[] = "$Id$"; |
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#endif |
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/* |
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Replacement for the posix popen() on Windows |
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|
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We don't just let the shell do the work like the original. |
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Since per default there's no decent shell around, we implement |
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the most basic functionality right here. |
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|
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currently supports mode "r" and | to chain several processes. |
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Substrings between matching quotes are considered one word, |
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ignoring any | within. Quotes don't nest. |
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|
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*/ |
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|
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#include <windows.h> |
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#include <stdlib.h> |
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#include <stdio.h> |
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#include <string.h> |
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#include <ctype.h> |
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#include <io.h> /* _open_osfhandle() */ |
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#include <fcntl.h> /* _O_RDONLY */ |
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|
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#include "paths.h" |
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#include "rtio.h" |
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#include "rterror.h" |
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|
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|
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#define RAD_MAX_PIPES 32 /* maximum number of pipes */ |
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|
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static int parse_pipes(char*, char**, int); |
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static BOOL createPipes(HANDLE*, HANDLE*, HANDLE*, HANDLE*); |
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static BOOL runChild(char*, char*, HANDLE, HANDLE, HANDLE); |
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static void resetStdHandles(HANDLE stdoutOrig, HANDLE stdinOrig); |
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|
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|
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int |
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pclose( /* posix pclose replacement */ |
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FILE* p |
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) |
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{ |
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fclose(p); |
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/* not sure if it's useful to wait for anything on Windows */ |
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return 0; |
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} |
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|
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|
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FILE * |
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popen( /* posix popen replacement */ |
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char* command, |
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char* type |
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) |
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{ |
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char *execfile, *args; |
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char *cmdlines[RAD_MAX_PIPES]; |
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char executable[512]; |
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int n, i; |
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int ncmds = 0; |
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HANDLE stdoutRd = NULL, stdoutWr = NULL; |
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HANDLE stdinRd = NULL, stdinWr = NULL; |
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HANDLE stderrWr = NULL; |
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HANDLE stdoutOrig, stdinOrig; |
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|
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stdoutOrig = GetStdHandle(STD_OUTPUT_HANDLE); |
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stdinOrig = GetStdHandle(STD_INPUT_HANDLE); |
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/* if we have a console, use it for error output */ |
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stderrWr = GetStdHandle(STD_ERROR_HANDLE); |
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|
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if((ncmds = parse_pipes(command, cmdlines, RAD_MAX_PIPES)) <= 0) { |
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eputs("Too many pipes or malformed command."); |
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goto error; |
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} |
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|
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for(n = 0; n < ncmds; ++n) { |
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if(!createPipes(&stdoutRd, &stdoutWr, |
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&stdinRd, &stdinWr)) { |
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eputs("Error creating pipe"); |
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goto error; |
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} |
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/* find the executable on the PATH */ |
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args = nextword(executable, sizeof(executable), cmdlines[n]); |
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if (args == NULL) { |
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eputs("Empty command."); |
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goto error; |
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} |
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execfile = getpath(executable, getenv("PATH"), X_OK); |
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if(execfile == NULL) { |
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char estr[512]; |
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_snprintf(estr, sizeof(estr), |
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"Can't find executable for \"%s\".", executable); |
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eputs(estr); |
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goto error; |
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} |
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if(!runChild(execfile, cmdlines[n], stdinRd, stdoutWr, stderrWr)) { |
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char estr[512]; |
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_snprintf(estr, sizeof(estr), |
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"Unable to execute executable \"%s\".", executable); |
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eputs(estr); |
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goto error; |
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} |
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/* close the stdout end just passed to the last process, |
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or the final read will block */ |
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CloseHandle(stdoutWr); |
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} |
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/* clean up */ |
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resetStdHandles(stdinOrig, stdoutOrig); |
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for (i = 0; i < ncmds; i++) free(cmdlines[i]); |
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|
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/* return a standard C file pointer for reading the output */ |
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return _fdopen(_open_osfhandle((long)stdoutRd, _O_RDONLY), "r"); |
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|
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error: |
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resetStdHandles(stdinOrig, stdoutOrig); |
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for (i = 0; i < ncmds; i++) free(cmdlines[i]); |
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return NULL; |
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} |
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|
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|
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static BOOL |
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createPipes( /* establish matching pipes for a subprocess */ |
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HANDLE* stdoutRd, |
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HANDLE* stdoutWr, |
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HANDLE* stdinRd, |
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HANDLE* stdinWr |
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) |
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{ |
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HANDLE stdoutRdInh = NULL; |
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HANDLE stdinWrInh = NULL; |
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HANDLE curproc; |
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SECURITY_ATTRIBUTES sAttr; |
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|
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curproc = GetCurrentProcess(); |
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|
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/* The rules of inheritance for handles are a mess. |
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Just to be safe, make all handles we pass to the |
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child processes inheritable */ |
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sAttr.nLength = sizeof(SECURITY_ATTRIBUTES); |
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sAttr.bInheritHandle = TRUE; |
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sAttr.lpSecurityDescriptor = NULL; |
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|
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if(*stdoutRd != NULL){ |
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/* if we have a previous stdout pipe, |
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assign the other end to stdin for the new process */ |
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CloseHandle(*stdinRd); |
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if(!DuplicateHandle(curproc, *stdoutRd, |
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curproc, stdinRd, 0, |
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TRUE, DUPLICATE_SAME_ACCESS)) |
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return FALSE; |
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CloseHandle(*stdoutRd); |
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if(!SetStdHandle(STD_INPUT_HANDLE, *stdinRd)) |
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return FALSE; |
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} else { |
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/* there's no previous stdout, create a new stdin pipe */ |
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if(!CreatePipe(stdinRd, &stdinWrInh, &sAttr, 0)) |
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return FALSE; |
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if(!SetStdHandle(STD_INPUT_HANDLE, *stdinRd)) |
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return FALSE; |
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CloseHandle(stdinWrInh); |
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} |
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|
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/* create the stdout pipe for the new process */ |
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if(!CreatePipe(&stdoutRdInh, stdoutWr, &sAttr, 0)) |
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return FALSE; |
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if(!SetStdHandle(STD_OUTPUT_HANDLE, *stdoutWr)) |
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return FALSE; |
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if(!DuplicateHandle(curproc, stdoutRdInh, |
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curproc, stdoutRd, 0, |
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FALSE, DUPLICATE_SAME_ACCESS)) |
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return FALSE; |
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CloseHandle(stdoutRdInh); |
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|
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return TRUE; |
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} |
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|
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|
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static void |
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resetStdHandles( /* clean up our std streams */ |
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HANDLE stdoutOrig, |
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HANDLE stdinOrig |
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) |
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{ |
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SetStdHandle(STD_OUTPUT_HANDLE, stdoutOrig); |
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SetStdHandle(STD_INPUT_HANDLE, stdinOrig); |
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} |
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|
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|
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static int |
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parse_pipes( /* split a shell command pipe sequence */ |
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char* s, |
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char* lines[], |
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int maxl |
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) |
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{ |
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int n = 0, i; |
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char *se, *ws; |
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int llen = 0; |
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int quote = 0; |
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|
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if (maxl<= 0) return 0; |
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if (s == NULL) { |
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return 0; |
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} |
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while (isspace(*s)) s++; /* leading whitespace */ |
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se = s; |
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while (n < maxl) { |
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switch (*se) { |
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case '"': |
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if (quote == '"') quote = 0; |
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else if (quote == 0) quote = '"'; |
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break; |
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case '\'': |
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if (quote == '\'') quote = 0; |
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else if (quote == 0) quote = '\''; |
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break; |
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case '|': |
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case '\0': |
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if (*se == '|' && quote) |
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break; |
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llen = se - s; |
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lines[n] = malloc(llen+1); |
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strncpy(lines[n], s, llen); |
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/* remove unix style line-end escapes */ |
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while((ws = strstr(lines[n], "\\\n")) != NULL) |
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*ws = *(ws+1) = ' '; |
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/* remove DOS style line-end escapes */ |
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while((ws = strstr(lines[n], "\\\r\n")) != NULL) |
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*ws = *(ws+1) = *(ws+2) = ' '; |
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while (isspace(*(lines[n] + llen - 1))) |
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llen--; /* trailing whitespace */ |
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lines[n][llen] = '\0'; |
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n++; |
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if (*se == '\0') return n; |
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s = se + 1; |
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while (isspace(*s)) s++; /* leading whitespace */ |
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se = s; |
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break; |
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default: |
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break; |
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} |
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se++; |
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} |
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/* more jobs than slots */ |
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for (i = 0; i < n; i++) free(lines[i]); |
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return -1; |
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} |
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|
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|
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static BOOL |
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runChild( /* start a child process with the right std streams */ |
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char* executable, |
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char* cmdline, |
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HANDLE stdinRd, |
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HANDLE stdoutWr, |
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HANDLE stderrWr |
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) |
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{ |
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PROCESS_INFORMATION procInfo; |
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STARTUPINFO startupInfo; |
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|
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/* use the given handles and don't display the console window */ |
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ZeroMemory(&startupInfo, sizeof(STARTUPINFO)); |
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startupInfo.cb = sizeof(STARTUPINFO); |
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startupInfo.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW; |
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startupInfo.wShowWindow = SW_HIDE; |
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startupInfo.hStdInput = stdinRd; |
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startupInfo.hStdOutput = stdoutWr; |
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startupInfo.hStdError = stderrWr; |
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|
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return CreateProcess(executable, cmdline, NULL, NULL, |
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TRUE, 0, |
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NULL, NULL, &startupInfo, &procInfo); |
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} |
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|
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|
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|
