2 * Copyright (c) 1988, 1989, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 * Copyright (c) 1989 by Berkeley Softworks
7 * This code is derived from software contributed to Berkeley by
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * @(#) Copyright (c) 1988, 1989, 1990, 1993 The Regents of the University of California. All rights reserved.
39 * @(#)main.c 8.3 (Berkeley) 3/19/94
40 * $FreeBSD: src/usr.bin/make/main.c,v 1.118 2005/02/13 13:33:56 harti Exp $
41 * $DragonFly: src/usr.bin/make/main.c,v 1.74 2005/04/16 10:34:26 okumoto Exp $
46 * The main file for this entire program. Exit routines etc
49 * Utility functions defined in this file:
51 * Takes a line of arguments, breaks them and
52 * treats them as if they were given when first
53 * invoked. Used by the parse module to implement
58 #include <sys/utsname.h>
60 #include <sys/param.h>
63 #include <sys/queue.h>
64 #include <sys/resource.h>
83 #include "pathnames.h"
90 #define WANT_ENV_MKLVL 1
91 #define MKLVL_MAXVAL 500
92 #define MKLVL_ENVVAR "__MKLVL__"
94 #define MAKEFLAGS ".MAKEFLAGS"
96 extern char **environ; /* XXX what header declares this variable? */
98 /* Targets to be made */
99 Lst create = Lst_Initializer(create);
101 time_t now; /* Time at start of make */
102 struct GNode *DEFAULT; /* .DEFAULT node */
103 Boolean allPrecious; /* .PRECIOUS given on line by itself */
105 static Boolean noBuiltins; /* -r flag */
107 /* ordered list of makefiles to read */
108 static Lst makefiles = Lst_Initializer(makefiles);
110 static Boolean expandVars; /* fully expand printed variables */
112 /* list of variables to print */
113 static Lst variables = Lst_Initializer(variables);
115 int maxJobs; /* -j argument */
116 static Boolean forceJobs; /* -j argument given */
117 Boolean compatMake; /* -B argument */
118 Boolean debug; /* -d flag */
119 Boolean noExecute; /* -n flag */
120 Boolean keepgoing; /* -k flag */
121 Boolean queryFlag; /* -q flag */
122 Boolean touchFlag; /* -t flag */
123 Boolean usePipes; /* !-P flag */
124 Boolean ignoreErrors; /* -i flag */
125 Boolean beSilent; /* -s flag */
126 Boolean beVerbose; /* -v flag */
127 Boolean oldVars; /* variable substitution style */
128 Boolean checkEnvFirst; /* -e flag */
130 /* (-E) vars to override from env */
131 Lst envFirstVars = Lst_Initializer(envFirstVars);
133 Boolean jobsRunning; /* TRUE if the jobs might be running */
135 char *chdir_verify_path(const char *, char *);
136 static int ReadMakefile(const char *);
137 static void usage(void);
139 static char *curdir; /* startup directory */
140 static char *objdir; /* where we chdir'ed to */
144 * Append a flag with an optional argument to MAKEFLAGS and MFLAGS
147 MFLAGS_append(const char *flag, char *arg)
151 Var_Append(MAKEFLAGS, flag, VAR_GLOBAL);
153 str = MAKEFLAGS_quote(arg);
154 Var_Append(MAKEFLAGS, str, VAR_GLOBAL);
158 Var_Append("MFLAGS", flag, VAR_GLOBAL);
160 str = MAKEFLAGS_quote(arg);
161 Var_Append("MFLAGS", str, VAR_GLOBAL);
168 * Parse a given argument vector. Called from main() and from
169 * Main_ParseArgLine() when the .MAKEFLAGS target is used.
171 * XXX: Deal with command line overriding .MAKEFLAGS in makefile
174 * Various global and local flags will be set depending on the flags
178 MainParseArgs(int argc, char **argv)
183 optind = 1; /* since we're called more than once */
185 #define OPTFLAGS "ABC:D:E:I:PSV:Xd:ef:ij:km:nqrstv"
186 while((c = getopt(argc, argv, OPTFLAGS)) != -1) {
191 MFLAGS_append("-A", NULL);
194 if (chdir(optarg) == -1)
195 err(1, "chdir %s", optarg);
198 Var_Set(optarg, "1", VAR_GLOBAL);
199 MFLAGS_append("-D", optarg);
202 Parse_AddIncludeDir(optarg);
203 MFLAGS_append("-I", optarg);
206 Lst_AtEnd(&variables, estrdup(optarg));
207 MFLAGS_append("-V", optarg);
214 MFLAGS_append("-B", NULL);
215 unsetenv("MAKE_JOBS_FIFO");
219 MFLAGS_append("-P", NULL);
223 MFLAGS_append("-S", NULL);
226 char *modules = optarg;
228 for (; *modules; ++modules)
246 if (modules[1] == '1') {
247 debug |= DEBUG_GRAPH1;
250 else if (modules[1] == '2') {
251 debug |= DEBUG_GRAPH2;
274 warnx("illegal argument to d option "
278 MFLAGS_append("-d", optarg);
282 Lst_AtEnd(&envFirstVars, estrdup(optarg));
283 MFLAGS_append("-E", optarg);
286 checkEnvFirst = TRUE;
287 MFLAGS_append("-e", NULL);
290 Lst_AtEnd(&makefiles, estrdup(optarg));
294 MFLAGS_append("-i", NULL);
300 maxJobs = strtol(optarg, &endptr, 10);
301 if (maxJobs <= 0 || *endptr != '\0') {
302 warnx("illegal number, -j argument -- %s",
306 MFLAGS_append("-j", optarg);
311 MFLAGS_append("-k", NULL);
314 Path_AddDir(&sysIncPath, optarg);
315 MFLAGS_append("-m", optarg);
319 MFLAGS_append("-n", NULL);
323 /* Kind of nonsensical, wot? */
324 MFLAGS_append("-q", NULL);
328 MFLAGS_append("-r", NULL);
332 MFLAGS_append("-s", NULL);
336 MFLAGS_append("-t", NULL);
340 MFLAGS_append("-v", NULL);
353 * Parse the rest of the arguments.
354 * o Check for variable assignments and perform them if so.
355 * o Check for more flags and restart getopt if so.
356 * o Anything else is taken to be a target and added
357 * to the end of the "create" list.
359 for (; *argv != NULL; ++argv, --argc) {
360 if (Parse_IsVar(*argv)) {
361 char *ptr = MAKEFLAGS_quote(*argv);
363 Var_Append(MAKEFLAGS, ptr, VAR_GLOBAL);
364 Parse_DoVar(*argv, VAR_CMD);
367 } else if ((*argv)[0] == '-') {
368 if ((*argv)[1] == '\0') {
370 * (*argv) is a single dash, so we
375 * (*argv) is a -flag, so backup argv
376 * and argc, since getopt() expects
377 * options to start in the 2nd position.
384 } else if ((*argv)[0] == '\0') {
385 Punt("illegal (null) argument.");
388 Lst_AtEnd(&create, estrdup(*argv));
395 * Used by the parse module when a .MFLAGS or .MAKEFLAGS target
396 * is encountered and by main() when reading the .MAKEFLAGS envariable.
397 * Takes a line of arguments and breaks it into its
398 * component words and passes those words and the number of them to the
399 * MainParseArgs function.
400 * The line should have all its leading whitespace removed.
403 * Only those that come from the various arguments.
406 Main_ParseArgLine(char *line, int mflags)
408 char **argv; /* Manufactured argument vector */
409 int argc; /* Number of arguments in argv */
413 for (; *line == ' '; ++line)
419 argv = MAKEFLAGS_break(line, &argc);
421 argv = brk_string(line, &argc, TRUE);
423 MainParseArgs(argc, argv);
427 chdir_verify_path(const char *path, char *obpath)
431 if (stat(path, &sb) == 0 && S_ISDIR(sb.st_mode)) {
432 if (chdir(path) == -1 || getcwd(obpath, MAXPATHLEN) == NULL) {
433 warn("warning: %s", path);
443 catch_child(int sig __unused)
448 * In lieu of a good way to prevent every possible looping in
449 * make(1), stop there from being more than MKLVL_MAXVAL processes forked
450 * by make(1), to prevent a forkbomb from happening, in a dumb and
454 check_make_level(void)
456 #ifdef WANT_ENV_MKLVL
457 char *value = getenv(MKLVL_ENVVAR);
458 int level = (value == NULL) ? 0 : atoi(value);
461 errc(2, EAGAIN, "Invalid value for recursion level (%d).",
463 } else if (level > MKLVL_MAXVAL) {
464 errc(2, EAGAIN, "Max recursion level (%d) exceeded.",
468 sprintf(new_value, "%d", level + 1);
469 setenv(MKLVL_ENVVAR, new_value, 1);
471 #endif /* WANT_ENV_MKLVL */
476 * The main function, for obvious reasons. Initializes variables
477 * and a few modules, then parses the arguments give it in the
478 * environment and on the command line. Reads the system makefile
479 * followed by either Makefile, makefile or the file given by the
480 * -f argument. Sets the .MAKEFLAGS PMake variable based on all the
481 * flags it has received by then uses either the Make or the Compat
482 * module to create the initial list of targets.
485 * If -q was given, exits -1 if anything was out-of-date. Else it exits
489 * The program exits when done. Targets are created. etc. etc. etc.
492 main(int argc, char **argv)
494 Boolean outOfDate = TRUE; /* FALSE if all targets up to date */
498 char mdpath[MAXPATHLEN];
499 char obpath[MAXPATHLEN];
500 char cdpath[MAXPATHLEN];
501 const char *machine = getenv("MACHINE");
502 const char *machine_arch = getenv("MACHINE_ARCH");
503 const char *machine_cpu = getenv("MACHINE_CPU");
504 char *cp = NULL, *start;
506 /* avoid faults on read-only strings */
507 static char syspath[] = PATH_DEFSYSPATH;
511 * Catch SIGCHLD so that we get kicked out of select() when we
512 * need to look at a child. This is only known to matter for the
513 * -j case (perhaps without -P).
515 * XXX this is intentionally misplaced.
519 sigemptyset(&sa.sa_mask);
520 sa.sa_flags = SA_RESTART | SA_NOCLDSTOP;
521 sa.sa_handler = catch_child;
522 sigaction(SIGCHLD, &sa, NULL);
529 * Turn off ENV to make ksh happier.
536 * get rid of resource limit on file descriptors
540 if (getrlimit(RLIMIT_NOFILE, &rl) != -1 &&
541 rl.rlim_cur != rl.rlim_max) {
542 rl.rlim_cur = rl.rlim_max;
543 setrlimit(RLIMIT_NOFILE, &rl);
548 * Get the name of this type of MACHINE from utsname
549 * so we can share an executable for similar machines.
550 * (i.e. m68k: amiga hp300, mac68k, sun3, ...)
552 * Note that while MACHINE is decided at run-time,
553 * MACHINE_ARCH is always known at compile time.
557 static struct utsname utsname;
559 if (uname(&utsname) == -1)
561 machine = utsname.machine;
569 machine_arch = "unknown";
571 machine_arch = MACHINE_ARCH;
576 * Set machine_cpu to the minumum supported CPU revision based
577 * on the target architecture, if not already set.
580 if (!strcmp(machine_arch, "i386"))
581 machine_cpu = "i386";
582 else if (!strcmp(machine_arch, "alpha"))
585 machine_cpu = "unknown";
589 beSilent = FALSE; /* Print commands as executed */
590 ignoreErrors = FALSE; /* Pay attention to non-zero returns */
591 noExecute = FALSE; /* Execute all commands */
592 keepgoing = FALSE; /* Stop on error */
593 allPrecious = FALSE; /* Remove targets when interrupted */
594 queryFlag = FALSE; /* This is not just a check-run */
595 noBuiltins = FALSE; /* Read the built-in rules */
596 touchFlag = FALSE; /* Actually update targets */
597 usePipes = TRUE; /* Catch child output in pipes */
598 debug = 0; /* No debug verbosity, please. */
601 maxJobs = DEFMAXJOBS;
602 forceJobs = FALSE; /* No -j flag */
603 compatMake = FALSE; /* No compat mode */
606 * Initialize the parsing, directory and variable modules to prepare
607 * for the reading of inclusion paths and variable settings on the
610 Dir_Init(); /* Initialize directory structures so -I flags
611 * can be processed correctly */
612 Var_Init(environ); /* As well as the lists of variables for
613 * parsing arguments */
617 * Initialize various variables.
618 * MAKE also gets this name, for compatibility
619 * .MAKEFLAGS gets set to the empty string just in case.
620 * MFLAGS also gets initialized empty, for compatibility.
622 Var_Set("MAKE", argv[0], VAR_GLOBAL);
623 Var_Set(MAKEFLAGS, "", VAR_GLOBAL);
624 Var_Set("MFLAGS", "", VAR_GLOBAL);
625 Var_Set("MACHINE", machine, VAR_GLOBAL);
626 Var_Set("MACHINE_ARCH", machine_arch, VAR_GLOBAL);
627 Var_Set("MACHINE_CPU", machine_cpu, VAR_GLOBAL);
629 Var_Set("MAKE_VERSION", MAKE_VERSION, VAR_GLOBAL);
633 * First snag things out of the MAKEFLAGS environment
634 * variable. Then parse the command line arguments.
636 Main_ParseArgLine(getenv("MAKEFLAGS"), 1);
638 MainParseArgs(argc, argv);
641 * Find where we are...
644 if (getcwd(curdir, MAXPATHLEN) == NULL)
650 if (stat(curdir, &sa) == -1)
651 err(2, "%s", curdir);
655 * The object directory location is determined using the
656 * following order of preference:
658 * 1. MAKEOBJDIRPREFIX`cwd`
660 * 3. PATH_OBJDIR.${MACHINE}
662 * 5. PATH_OBJDIRPREFIX`cwd`
664 * If one of the first two fails, use the current directory.
665 * If the remaining three all fail, use the current directory.
667 * Once things are initted,
668 * have to add the original directory to the search path,
669 * and modify the paths for the Makefiles apropriately. The
670 * current directory is also placed as a variable for make scripts.
672 if (!(pathp = getenv("MAKEOBJDIRPREFIX"))) {
673 if (!(path = getenv("MAKEOBJDIR"))) {
675 pathp = PATH_OBJDIRPREFIX;
676 snprintf(mdpath, MAXPATHLEN, "%s.%s",
678 if (!(objdir = chdir_verify_path(mdpath, obpath)))
679 if (!(objdir=chdir_verify_path(path, obpath))) {
680 snprintf(mdpath, MAXPATHLEN,
681 "%s%s", pathp, curdir);
682 if (!(objdir=chdir_verify_path(mdpath,
687 else if (!(objdir = chdir_verify_path(path, obpath)))
691 snprintf(mdpath, MAXPATHLEN, "%s%s", pathp, curdir);
692 if (!(objdir = chdir_verify_path(mdpath, obpath)))
695 Dir_InitDot(); /* Initialize the "." directory */
696 if (objdir != curdir)
697 Path_AddDir(&dirSearchPath, curdir);
698 Var_Set(".DIRECTIVE_MAKEENV", "YES", VAR_GLOBAL);
699 Var_Set(".ST_EXPORT", "YES", VAR_GLOBAL);
700 Var_Set(".CURDIR", curdir, VAR_GLOBAL);
701 Var_Set(".OBJDIR", objdir, VAR_GLOBAL);
703 if (getenv("MAKE_JOBS_FIFO") != NULL)
706 * Be compatible if user did not specify -j and did not explicitly
707 * turned compatibility on
709 if (!compatMake && !forceJobs)
713 * Initialize target and suffix modules in preparation for
714 * parsing the makefile(s)
723 * Set up the .TARGETS variable to contain the list of targets to be
724 * created. If none specified, make the variable empty -- the parser
725 * will fill the thing in with the default or .MAIN target.
727 if (!Lst_IsEmpty(&create)) {
730 for (ln = Lst_First(&create); ln != NULL; ln = Lst_Succ(ln)) {
731 char *name = Lst_Datum(ln);
733 Var_Append(".TARGETS", name, VAR_GLOBAL);
736 Var_Set(".TARGETS", "", VAR_GLOBAL);
740 * If no user-supplied system path was given (through the -m option)
741 * add the directories from the DEFSYSPATH (more than one may be given
742 * as dir1:...:dirn) to the system include path.
744 if (TAILQ_EMPTY(&sysIncPath)) {
745 for (start = syspath; *start != '\0'; start = cp) {
746 for (cp = start; *cp != '\0' && *cp != ':'; cp++)
749 Path_AddDir(&sysIncPath, start);
752 Path_AddDir(&sysIncPath, start);
758 * Read in the built-in rules first, followed by the specified
759 * makefile, if it was (makefile != (char *) NULL), or the default
760 * Makefile and makefile, in that order, if it wasn't.
764 Lst sysMkPath = Lst_Initializer(sysMkPath);
767 Path_Expand(PATH_DEFSYSMK, &sysIncPath, &sysMkPath);
768 if (Lst_IsEmpty(&sysMkPath))
769 Fatal("make: no system rules (%s).", PATH_DEFSYSMK);
770 LST_FOREACH(ln, &sysMkPath) {
771 if (!ReadMakefile(Lst_Datum(ln)))
775 Fatal("make: cannot open %s.", (char *)Lst_Datum(ln));
776 Lst_Destroy(&sysMkPath, free);
779 if (!Lst_IsEmpty(&makefiles)) {
782 LST_FOREACH(ln, &makefiles) {
783 if (!ReadMakefile(Lst_Datum(ln)))
787 Fatal("make: cannot open %s.", (char *)Lst_Datum(ln));
788 } else if (!ReadMakefile("BSDmakefile"))
789 if (!ReadMakefile("makefile"))
790 ReadMakefile("Makefile");
792 ReadMakefile(".depend");
794 /* Install all the flags into the MAKE envariable. */
795 if (((p = Var_Value(MAKEFLAGS, VAR_GLOBAL, &p1)) != NULL) && *p)
796 setenv("MAKEFLAGS", p, 1);
800 * For compatibility, look at the directories in the VPATH variable
801 * and add them to the search path, if the variable is defined. The
802 * variable's value is in the same format as the PATH envariable, i.e.
803 * <directory>:<directory>:<directory>...
805 if (Var_Exists("VPATH", VAR_CMD)) {
807 * GCC stores string constants in read-only memory, but
808 * Var_Subst will want to write this thing, so store it
811 static char VPATH[] = "${VPATH}";
817 buf = Var_Subst(VPATH, VAR_CMD, FALSE);
819 vpath = Buf_Data(buf);
821 /* skip to end of directory */
822 for (ptr = vpath; *ptr != ':' && *ptr != '\0'; ptr++)
825 /* Save terminator character so know when to stop */
829 /* Add directory to search path */
830 Path_AddDir(&dirSearchPath, vpath);
833 } while (savec != '\0');
835 Buf_Destroy(buf, TRUE);
839 * Now that all search paths have been read for suffixes et al, it's
840 * time to add the default search path to their lists...
844 /* print the initial graph, if the user requested it */
848 /* print the values of any variables requested by the user */
849 if (Lst_IsEmpty(&variables)) {
851 * Since the user has not requested that any variables
852 * be printed, we can build targets.
854 * Have read the entire graph and need to make a list of targets
855 * to create. If none was given on the command line, we consult
856 * the parsing module to find the main target(s) to create.
858 Lst targs = Lst_Initializer(targs);
860 if (Lst_IsEmpty(&create))
861 Parse_MainName(&targs);
863 Targ_FindList(&targs, &create, TARG_CREATE);
867 * Compat_Init will take care of creating
868 * all the targets as well as initializing
875 * Initialize job module before traversing
876 * the graph, now that any .BEGIN and .END
877 * targets have been read. This is done
878 * only if the -q flag wasn't given (to
879 * prevent the .BEGIN from being executed
887 /* Traverse the graph, checking on all the targets */
888 outOfDate = Make_Run(&targs);
890 Lst_Destroy(&targs, NOFREE);
894 * Print the values of any variables requested by
899 LST_FOREACH(n, &variables) {
900 const char *name = Lst_Datum(n);
905 v = emalloc(strlen(name) + 1 + 3);
906 sprintf(v, "${%s}", name);
908 value = Buf_Peel(Var_Subst(v,
910 printf("%s\n", value);
917 value = Var_Value(name, VAR_GLOBAL, &v);
918 printf("%s\n", value != NULL ? value : "");
925 Lst_Destroy(&variables, free);
926 Lst_Destroy(&makefiles, free);
927 Lst_Destroy(&create, free);
929 /* print the graph now it's been processed if the user requested it */
933 if (queryFlag && outOfDate)
941 * Open and parse the given makefile.
944 * TRUE if ok. FALSE if couldn't open file.
950 ReadMakefile(const char *p)
952 char *fname; /* makefile to read */
954 char *name, path[MAXPATHLEN];
958 /* XXX - remove this once constification is done */
961 if (!strcmp(fname, "-")) {
962 Parse_File("(stdin)", stdin);
963 Var_Set("MAKEFILE", "", VAR_GLOBAL);
965 setMAKEFILE = strcmp(fname, ".depend");
967 /* if we've chdir'd, rebuild the path name */
968 if (curdir != objdir && *fname != '/') {
969 snprintf(path, MAXPATHLEN, "%s/%s", curdir, fname);
971 * XXX The realpath stuff breaks relative includes
972 * XXX in some cases. The problem likely is in
973 * XXX parse.c where it does special things in
974 * XXX ParseDoInclude if the file is relateive
975 * XXX or absolute and not a system file. There
976 * XXX it assumes that if the current file that's
977 * XXX being included is absolute, that any files
978 * XXX that it includes shouldn't do the -I path
979 * XXX stuff, which is inconsistant with historical
980 * XXX behavior. However, I can't pentrate the mists
981 * XXX further, so I'm putting this workaround in
982 * XXX here until such time as the underlying bug
985 #if THIS_BREAKS_THINGS
986 if (realpath(path, path) != NULL &&
987 (stream = fopen(path, "r")) != NULL) {
992 } else if (realpath(fname, path) != NULL) {
995 if ((stream = fopen(fname, "r")) != NULL)
999 if ((stream = fopen(path, "r")) != NULL) {
1006 if ((stream = fopen(fname, "r")) != NULL)
1010 /* look in -I and system include directories. */
1011 name = Path_FindFile(fname, &parseIncPath);
1013 name = Path_FindFile(fname, &sysIncPath);
1014 if (!name || !(stream = fopen(name, "r")))
1016 MAKEFILE = fname = name;
1018 * set the MAKEFILE variable desired by System V fans -- the
1019 * placement of the setting here means it gets set to the last
1020 * makefile specified, as it is set by SysV make.
1024 Var_Set("MAKEFILE", MAKEFILE, VAR_GLOBAL);
1025 Parse_File(fname, stream);
1033 * Execute the command in cmd, and return the output of that command
1037 * A string containing the output of the command, or the empty string
1038 * If error is not NULL, it contains the reason for the command failure
1041 * The string must be freed by the caller.
1044 Cmd_Exec(const char *cmd, const char **error)
1046 int fds[2]; /* Pipe streams */
1047 int cpid; /* Child PID */
1048 int pid; /* PID from wait() */
1049 int status; /* command exit status */
1050 Buffer *buf; /* buffer to store the result */
1056 if (shellPath == NULL)
1059 * Open a pipe for fetching its output
1061 if (pipe(fds) == -1) {
1062 *error = "Couldn't create pipe for \"%s\"";
1069 switch (cpid = vfork()) {
1072 * Close input side of pipe
1077 * Duplicate the output stream to the shell's output, then
1078 * shut the extra thing down. Note we don't fetch the error
1079 * stream...why not? Why?
1087 /* Set up arguments for shell */
1088 args[0] = shellName;
1093 execv(shellPath, args);
1099 *error = "Couldn't exec \"%s\"";
1104 * No need for the writing half
1109 char result[BUFSIZ];
1111 rcnt = read(fds[0], result, sizeof(result));
1113 Buf_AddBytes(buf, (size_t)rcnt, (Byte *)result);
1114 } while (rcnt > 0 || (rcnt == -1 && errno == EINTR));
1117 *error = "Error reading shell's output for \"%s\"";
1120 * Close the input side of the pipe.
1125 * Wait for the process to exit.
1127 while (((pid = wait(&status)) != cpid) && (pid >= 0))
1131 *error = "\"%s\" returned non-zero status";
1133 Buf_StripNewlines(buf);
1142 * exit with usage message
1147 fprintf(stderr, "%s\n%s\n%s\n",
1148 "usage: make [-BPSXeiknqrstv] [-C directory] [-D variable] [-d flags]",
1149 " [-E variable] [-f makefile] [-I directory] [-j max_jobs]",
1150 " [-m directory] [-V variable] [variable=value] [target ...]");