X-Git-Url: https://git.saurik.com/apple/system_cmds.git/blobdiff_plain/2fc1e207eccd68aee093ed29dae719e77bac17dd..b58caf92d598c70ddd398b3909b0a2b8b5a110e1:/arch.tproj/arch.c

diff --git a/arch.tproj/arch.c b/arch.tproj/arch.c
index 0e140fe..426fea0 100644
--- a/arch.tproj/arch.c
+++ b/arch.tproj/arch.c
@@ -1,81 +1,711 @@
 /*
- * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1999-2016 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
- * 
- * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
- * Reserved.  This file contains Original Code and/or Modifications of
- * Original Code as defined in and that are subject to the Apple Public
- * Source License Version 1.0 (the 'License').  You may not use this file
- * except in compliance with the License.  Please obtain a copy of the
- * License at http://www.apple.com/publicsource and read it before using
- * this file.
- * 
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License."
- * 
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
  * @APPLE_LICENSE_HEADER_END@
  */
-/*
- * arch.c - determine the architecture of the machine ran on
- */
 
+#include <sys/cdefs.h>
 #include <stdio.h>
 #include <string.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <spawn.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+#include <paths.h>
+#include <err.h>
 #include <mach/mach.h>
 #include <mach-o/arch.h>
+#include <limits.h>
+#include <sys/fcntl.h>
+#include <glob.h>
+#include <CoreFoundation/CoreFoundation.h>
+#include <NSSystemDirectories.h>
+#include <sysdir.h>
+
+#ifndef ARCH_PROG
+#define ARCH_PROG	"arch"
+#endif
+#ifndef MACHINE_PROG
+#define MACHINE_PROG	"machine"
+#endif
+
+#define kKeyExecPath "ExecutablePath"
+#define kKeyPlistVersion "PropertyListVersion"
+#define kKeyPrefOrder "PreferredOrder"
+#define kPlistExtension ".plist"
+#define kSettingsDir "archSettings"
+
+static const char envname[] = "ARCHPREFERENCE";
+
+/* The CPU struct contains the argument buffer to posix_spawnattr_setbinpref_np */
+
+typedef struct {
+    cpu_type_t *buf;
+    int errs;
+    size_t count;
+    size_t capacity;
+} CPU;
+
+typedef struct {
+    const char *arch;
+    cpu_type_t cpu;
+} CPUTypes;
+
+static const CPUTypes knownArchs[] = {
+#if defined(__i386__) || defined(__x86_64__)
+    {"i386", CPU_TYPE_I386},
+    {"x86_64", CPU_TYPE_X86_64},
+#elif defined(__arm__)
+    {"arm", CPU_TYPE_ARM},
+#else
+#error "Unsupported architecture"
+#endif
+};
+
+/* environment SPI */
+char **_copyenv(char **env);
+int _setenvp(const char *name, const char *value, int rewrite, char ***envp, void *state);
+int _unsetenvp(const char *name, char ***envp, void *state);
+
+/* copy of environment */
+char **envCopy = NULL;
+extern char **environ;
+
+/*
+ * The native 32 and 64-bit architectures (this is relative to the architecture
+ * the arch command is running.  NULL means unsupported.
+ */
+#if defined(__i386__) || defined(__x86_64__)
+#define NATIVE_32	"i386"
+#define NATIVE_64	"x86_64"
+#elif defined(__arm__)
+#define NATIVE_32	"arm"
+#define NATIVE_64	NULL
+#else
+#error "Unsupported architecture"
+#endif
+bool unrecognizednative32seen = false;
+bool unrecognizednative64seen = false;
+
+/*
+ * arch - perform the original behavior of the arch and machine commands.
+ * The archcmd flag is non-zero for the arch command, zero for the machine
+ * command.  This routine never returns.
+ */
+static void __dead2
+arch(int archcmd)
+{
+    const NXArchInfo *arch = NXGetLocalArchInfo();
+
+    if(!arch)
+        errx(-1, "Unknown architecture.");
+    if(archcmd) {
+        arch = NXGetArchInfoFromCpuType(arch->cputype, CPU_SUBTYPE_MULTIPLE);
+        if(!arch)
+            errx(-1, "Unknown architecture.");
+    }
+    printf("%s%s", arch->name, (isatty(STDIN_FILENO) ? "\n" : ""));
+    exit(0);
+}
+
+/*
+ * spawnIt - run the posix_spawn command.  cpu is the auto-sizing CPU structure.
+ * pflag is non-zero to call posix_spawnp; zero means to call posix_spawn.
+ * str is the name/path to pass to posix_spawn{,p}, and argv are
+ * the argument arrays to pass.  This routine never returns.
+ */
+static void __dead2
+spawnIt(CPU *cpu, int pflag, const char *str, char **argv)
+{
+    posix_spawnattr_t attr;
+    pid_t pid;
+    int ret;
+    size_t copied;
+    size_t count = cpu->count;
+    cpu_type_t *prefs = cpu->buf;
+
+    if(count == 0) {
+        if(unrecognizednative32seen)
+            warnx("Unsupported native 32-bit architecture");
+        if(unrecognizednative64seen)
+            warnx("Unsupported native 64-bit architecture");
+        exit(1);
+    }
+
+    if(unrecognizednative32seen)
+        fprintf(stderr, "warning: unsupported native 32-bit architecture\n");
+    if(unrecognizednative64seen)
+        fprintf(stderr, "warning: unsupported native 64-bit architecture\n");
+
+    if((ret = posix_spawnattr_init(&attr)) != 0)
+        errc(1, ret, "posix_spawnattr_init");
+    /* do the equivalent of exec, rather than creating a separate process */
+    if((ret = posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETEXEC)) != 0)
+        errc(1, ret, "posix_spawnattr_setflags");
+    if((ret = posix_spawnattr_setbinpref_np(&attr, count, prefs, &copied)) != 0)
+        errc(1, ret, "posix_spawnattr_setbinpref_np");
+    if(copied != count)
+        errx(1, "posix_spawnattr_setbinpref_np only copied %lu of %lu", copied, count);
+    if(pflag)
+        ret = posix_spawnp(&pid, str, NULL, &attr, argv, envCopy ? envCopy : environ);
+    else
+        ret = posix_spawn(&pid, str, NULL, &attr, argv, envCopy ? envCopy : environ);
+    errc(1, ret, "posix_spawn%s: %s", (pflag ? "p" : ""), str);
+}
+
+/*
+ * initCPU - initialize a CPU structure, a dynamically expanding CPU types
+ * array.
+ */
+static void
+initCPU(CPU *cpu)
+{
+    cpu->errs = 0;
+    cpu->count = 0;
+    cpu->capacity = 1;
+    cpu->buf = (cpu_type_t *)malloc(cpu->capacity * sizeof(cpu_type_t));
+    if(!cpu->buf)
+        err(1, "Failed to malloc CPU buffer");
+}
+
+/*
+ * addCPU - add a new CPU type value to the CPU structure, expanding
+ * the array as necessary.
+ */
+static void
+addCPU(CPU *cpu, cpu_type_t n)
+{
+    if(cpu->count == cpu->capacity) {
+        cpu_type_t *newcpubuf;
+        
+        cpu->capacity *= 2;
+        newcpubuf = (cpu_type_t *)realloc(cpu->buf, cpu->capacity * sizeof(cpu_type_t));
+        if(!newcpubuf)
+            err(1, "Out of memory realloc-ing CPU structure");
+        cpu->buf = newcpubuf;
+    }
+    cpu->buf[cpu->count++] = n;
+}
+
+/*
+ * addCPUbyname - add a new CPU type, given by name, to the CPU structure,
+ * expanding the array as necessary.  The name is converted to a type value
+ * by the ArchDict dictionary.
+ */
+static void
+addCPUbyname(CPU *cpu, const char *name)
+{
+    int i;
+    
+    for (i=0; i < sizeof(knownArchs)/sizeof(knownArchs[0]); i++) {
+        if (0 == strcasecmp(name, knownArchs[i].arch)) {
+            addCPU(cpu, knownArchs[i].cpu);
+            return;
+        }
+    }
+    
+    /* Didn't match a string in knownArchs */
+    warnx("Unknown architecture: %s", name);
+    cpu->errs++;
+}
+
+/*
+ * useEnv - parse the environment variable for CPU preferences.  Use name
+ * to look for program-specific preferences, and append any CPU types to cpu.
+ * Returns the number of CPU types.  Returns any specified execute path in
+ * execpath. 
+ *
+ * The environment variable ARCHPREFERENCE has the format:
+ *    spec[;spec]...
+ * a semicolon separated list of specifiers.  Each specifier has the format:
+ *    [prog:[execpath:]]type[,type]...
+ * a comma separate list of CPU type names, optionally proceeded by a program
+ * name and an execpath.  If program name exist, that types only apply to that
+ * program.  If execpath is specified, it is returned.  If no program name
+ * exists, then it applies to all programs.  So ordering of the specifiers is
+ * important, as the default (no program name) specifier must be last.
+ */
+static size_t
+useEnv(CPU *cpu, const char *name, char **execpath)
+{
+    char *val = getenv(envname);
+    if(!val)
+        return 0;
+    
+    /* cp will point to the basename of name */
+    const char *cp = strrchr(name, '/');
+    if(cp) {
+        cp++;
+        if(!*cp)
+            errx(1, "%s: no name after last slash", name);
+    } else
+        cp = name;
+    /* make a copy of the environment variable value, so we can modify it */
+    val = strdup(val);
+    if(!val)
+        err(1, "Can't copy environment %s", envname);
+    char *str = val;
+    char *blk;
+    /* for each specifier */
+    while((blk = strsep(&str, ";")) != NULL) {
+        if(*blk == 0)
+            continue; /* two adjacent semicolons */
+        /* now split on colons */
+        char *n = strsep(&blk, ":");
+        if(blk) {
+            char *p = strsep(&blk, ":");
+            if(!blk) { /* there is only one colon, so no execpath */
+                blk = p;
+                p = NULL;
+            } else if(!*p) /* two consecutive colons, so no execpath */
+                p = NULL;
+            if(!*blk)
+                continue; /* no cpu list, so skip */
+            /* if the name matches, or there is no name, process the cpus */
+            if(!*n || strcmp(n, cp) == 0) {
+                if(cpu->count == 0) { /* only if we haven't processed architectures */
+                    char *t;
+                    while((t = strsep(&blk, ",")) != NULL)
+                        addCPUbyname(cpu, t);
+                }
+                *execpath = (*n ? p : NULL); /* only use the exec path is name is set */
+                break;
+            }
+        } else { /* no colons at all, so process as default */
+            if(cpu->count == 0) { /* only if we haven't processed architectures */
+                blk = n;
+                while((n = strsep(&blk, ",")) != NULL)
+                    addCPUbyname(cpu, n);
+            }
+            *execpath = NULL;
+            break;
+        }
+    }
+    if(cpu->errs) /* errors during addCPUbyname are fatal */
+        exit(1);
+    return cpu->count; /* return count of architectures */
+}
+
+/*
+ * spawnFromPreference - called when argv[0] is not "arch" or "machine", or
+ * argv[0] was arch, but no commandline architectures were specified.
+ * If the environment variable ARCHPREFERENCE is specified, and there is a
+ * match to argv[0], use the specified cpu preferences.  If no exec path
+ * is specified in ARCHPREFERENCE, or no match is found in ARCHPREFERENCE,
+ * get any additional information from a .plist file with the name of argv[0].
+ * This routine never returns.
+ */
+static void __dead2
+spawnFromPreferences(CPU *cpu, int needexecpath, char **argv)
+{
+    char *epath = NULL;
+    char fpath[PATH_MAX];
+    char execpath2[PATH_MAX];
+    CFDictionaryRef plist = NULL;
+    sysdir_search_path_enumeration_state state;
+    size_t count, i;
+    const char *prog = strrchr(*argv, '/');
+
+    if(prog)
+        prog++;
+    else
+        prog = *argv;
+    if(!*prog)
+        errx(1, "Not program name specified");
+
+    /* check the environment variable first */
+    if((count = useEnv(cpu, prog, &epath)) > 0) {
+        /* if we were called as arch, use posix_spawnp */
+        if(!needexecpath)
+            spawnIt(cpu, 1, (epath ? epath : *argv), argv);
+        /* otherwise, if we have the executable path, call posix_spawn */
+        if(epath)
+            spawnIt(cpu, 0, epath, argv);
+    }
+
+    state = sysdir_start_search_path_enumeration(SYSDIR_DIRECTORY_LIBRARY, SYSDIR_DOMAIN_MASK_ALL);
+    while ((state = sysdir_get_next_search_path_enumeration(state, fpath))) {
+
+        if (fpath[0] == '~') {
+            glob_t pglob;
+            int gret;
+
+            bzero(&pglob, sizeof(pglob));
+
+            gret = glob(fpath, GLOB_TILDE, NULL, &pglob);
+            if (gret == 0) {
+                int i;
+                for (i=0; i < pglob.gl_pathc; i++) {
+                    /* take the first glob expansion */
+                    strlcpy(fpath, pglob.gl_pathv[i], sizeof(fpath));
+                    break;
+                }
+            }
+            globfree(&pglob);
+        }
+
+        // Handle path
+        strlcat(fpath, "/" kSettingsDir "/", sizeof(fpath));
+        strlcat(fpath, prog, sizeof(fpath));
+        strlcat(fpath, kPlistExtension, sizeof(fpath));
+        // printf("component: %s\n", fpath);
+
+        int fd, ret;
+        size_t length;
+        ssize_t rsize;
+        struct stat sb;
+        void *buffer;
+        fd = open(fpath, O_RDONLY, 0);
+        if (fd >= 0) {
+            ret = fstat(fd, &sb);
+            if (ret == 0) {
+                if (sb.st_size <= SIZE_T_MAX) {
+                    length = (size_t)sb.st_size;
+                    buffer = malloc(length); /* ownership transferred to CFData */
+                    if (buffer) {
+                        rsize = read(fd, buffer, length);
+                        if (rsize == length) {
+                            CFDataRef data = CFDataCreateWithBytesNoCopy(kCFAllocatorDefault, buffer, length, kCFAllocatorMalloc);
+                            if (data) {
+                                buffer = NULL;
+                                plist = CFPropertyListCreateWithData(kCFAllocatorDefault, data, kCFPropertyListImmutable, NULL, NULL);
+                                CFRelease(data);
+                            }
+                        }
+                        if (buffer) {
+                            free(buffer);
+                        }
+                    }
+                }
+            }
+            close(fd);
+        }
+
+        if (plist) {
+            break;
+        }
+    }
+
+    if (plist) {
+        if (CFGetTypeID(plist) != CFDictionaryGetTypeID())
+            errx(1, "%s: plist not a dictionary", fpath);
+    } else {
+        errx(1, "Can't find any plists for %s", prog);
+    }
+
+    int errs = 0; /* scan for all errors and fail later */
+    do { /* begin block */
+        /* check the plist version */
+        CFStringRef vers = CFDictionaryGetValue(plist, CFSTR(kKeyPlistVersion));
+        if(!vers) {
+            warnx("%s: No key %s", fpath, kKeyPlistVersion);
+            errs++;
+        } else if(CFGetTypeID(vers) != CFStringGetTypeID()) {
+            warnx("%s: %s is not a string", fpath, kKeyPlistVersion);
+            errs++;
+        } else if(!CFEqual(vers, CFSTR("1.0"))) {
+            warnx("%s: %s not 1.0", fpath, kKeyPlistVersion);
+            errs++;
+        }
+        /* get the execpath */
+        CFStringRef execpath = CFDictionaryGetValue(plist, CFSTR(kKeyExecPath));
+        if(!execpath) {
+            warnx("%s: No key %s", fpath, kKeyExecPath);
+            errs++;
+        } else if(CFGetTypeID(execpath) != CFStringGetTypeID()) {
+            warnx("%s: %s is not a string", fpath, kKeyExecPath);
+            errs++;
+        }
+        if (!CFStringGetFileSystemRepresentation(execpath, execpath2, sizeof(execpath2))) {
+            warnx("%s: could not get exec path", fpath);
+            errs++;
+        }
+        /* if we already got cpu preferences from ARCHPREFERENCE, we are done */
+        if(count > 0)
+            break;
+        /* otherwise, parse the cpu preferences from the plist */
+        CFArrayRef p = CFDictionaryGetValue(plist, CFSTR(kKeyPrefOrder));
+        if(!p) {
+            warnx("%s: No key %s", fpath, kKeyPrefOrder);
+            errs++;
+        } else if(CFGetTypeID(p) != CFArrayGetTypeID()) {
+            warnx("%s: %s is not an array", fpath, kKeyPrefOrder);
+            errs++;
+        } else if((count = CFArrayGetCount(p)) == 0) {
+            warnx("%s: no entries in %s", fpath, kKeyPrefOrder);
+            errs++;
+        } else {
+            /* finally build the cpu type array */
+            for(i = 0; i < count; i++) {
+                CFStringRef a = CFArrayGetValueAtIndex(p, i);
+                if(CFGetTypeID(a) != CFStringGetTypeID()) {
+                    warnx("%s: entry %lu of %s is not a string", fpath, i, kKeyPrefOrder);
+                    errs++;
+                } else {
+                    char astr[128];
+                    if (CFStringGetCString(a, astr, sizeof(astr), kCFStringEncodingASCII)) {
+                        addCPUbyname(cpu, astr);
+                    }
+                }
+            }
+        }
+    } while(0); /* end block */
+    if(errs) /* exit if there were any reported errors */
+        exit(1);
+
+    CFRelease(plist);
+
+    /* call posix_spawn */
+    spawnIt(cpu, 0, execpath2, argv);
+}
 
-char *
-  get_progname (char *name)
+static void __dead2
+usage(int ret)
 {
-  char *tmp;
-  if (tmp = strrchr(name,'/'))
-    return tmp+1;
-  else return name;
+    fprintf(stderr,
+            "Usage: %s\n"
+            "       Display the machine's architecture type\n"
+            "Usage: %s {-arch_name | -arch arch_name} ... [-c] [-d envname] ... [-e envname=value] ... [-h] prog [arg ...]\n"
+            "       Run prog with any arguments, using the given architecture\n"
+            "       order.  If no architectures are specified, use the\n"
+            "       ARCHPREFERENCE environment variable, or a property list file.\n"
+            "       -c will clear out all environment variables before running prog.\n"
+            "       -d will delete the given environment variable before running prog.\n"
+            "       -e will add the given environment variable/value before running prog.\n"
+            "       -h will print usage message and exit.\n",
+            ARCH_PROG, ARCH_PROG);
+    exit(ret);
 }
 
-int 
-  main (int argc, char **argv)
+/*
+ * wrapped - check the path to see if it is a link to /usr/bin/arch.
+ */
+static int
+wrapped(const char *name)
 {
-  char *progname;
-  const NXArchInfo *arch;
+    size_t lp, ln;
+    char *p;
+    char *bp = NULL;
+    char *cur, *path;
+    char buf[MAXPATHLEN], rpbuf[MAXPATHLEN];
+    struct stat sb;
+
+    ln = strlen(name);
+
+    do { /* begin block */
+        /* If it's an absolute or relative path name, it's easy. */
+        if(index(name, '/')) {
+            if(stat(name, &sb) == 0 && S_ISREG(sb.st_mode) && access(name, X_OK) == 0) {
+                bp = (char *)name;
+                break;
+            }
+            errx(1, "%s isn't executable", name);
+        }
+
+        /* search the PATH, looking for name */
+        if((path = getenv("PATH")) == NULL)
+            path = _PATH_DEFPATH;
+
+        cur = alloca(strlen(path) + 1);
+        if(cur == NULL)
+            err(1, "alloca");
+        strcpy(cur, path);
+        while((p = strsep(&cur, ":")) != NULL) {
+            /*
+             * It's a SHELL path -- double, leading and trailing colons
+             * mean the current directory.
+             */
+            if(*p == '\0') {
+                p = ".";
+                lp = 1;
+            } else
+                lp = strlen(p);
+
+            /*
+             * If the path is too long complain.  This is a possible
+             * security issue; given a way to make the path too long
+             * the user may execute the wrong program.
+             */
+            if(lp + ln + 2 > sizeof(buf)) {
+                warn("%s: path too long", p);
+                continue;
+            }
+            bcopy(p, buf, lp);
+            buf[lp] = '/';
+            bcopy(name, buf + lp + 1, ln);
+            buf[lp + ln + 1] = '\0';
+            if(stat(buf, &sb) == 0 && S_ISREG(sb.st_mode) && access(buf, X_OK) == 0) {
+                bp = buf;
+                break;
+            }
+        }
+        if(p == NULL)
+            errx(1, "Can't find %s in PATH", name);
+    } while(0); /* end block */
+    if(realpath(bp, rpbuf) == NULL)
+        errx(1, "realpath failed on %s", bp);
+    return (strcmp(rpbuf, "/usr/bin/" ARCH_PROG) == 0);
+}
+
+/*
+ * spawnFromArgs - called when arch has arguments specified.  The arch command
+ * line arguments are:
+ * % arch [[{-xxx | -arch xxx}]...] prog [arg]...
+ * where xxx is a cpu name, and the command to execute and its arguments follow.
+ * If no commandline cpu names are given, the environment variable
+ * ARCHPREFERENCE is used.  This routine never returns.
+ */
+
+#define MATCHARG(a,m)	({ \
+    const char *arg = *(a); \
+    if(arg[1] == '-') arg++; \
+    strcmp(arg, (m)) == 0; \
+})
+
+#define MATCHARGWITHVALUE(a,m,n,e)	({ \
+    const char *ret = NULL; \
+    const char *arg = *(a); \
+    if(arg[1] == '-') arg++; \
+    if(strcmp(arg, (m)) == 0) { \
+        if(*++(a) == NULL) { \
+            warnx(e); \
+            usage(1); \
+        } \
+        ret = *(a); \
+    } else if(strncmp(arg, (m), (n)) == 0 && arg[n] == '=') { \
+         ret = arg + (n) + 1; \
+    } \
+    ret; \
+})
 
-  if (argc > 1)
-    {
-      fprintf (stderr,"*error: %s takes no arguments\n",argv[0]);
-      exit (-1);
+#define MAKEENVCOPY(e)	\
+    if(!envCopy) { \
+        envCopy = _copyenv(environ); \
+        if(envCopy == NULL) \
+            errx(1, (e)); \
     }
-  arch = NXGetLocalArchInfo();
-  if (arch == NULL)
-    {
-      fprintf (stderr,"Unknown architecture.\n");
-      exit(-1);
+
+static void __dead2
+spawnFromArgs(CPU *cpu, char **argv)
+{
+    const char *ap, *ret;
+
+    /* process arguments */
+    for(argv++; *argv && **argv == '-'; argv++) {
+        if((ret = MATCHARGWITHVALUE(argv, "-arch", 5, "-arch without architecture"))) {
+            ap = ret;
+        } else if(MATCHARG(argv, "-32")) {
+            ap = NATIVE_32;
+            if(!ap) {
+                unrecognizednative32seen = true;
+                continue;
+            }
+        } else if(MATCHARG(argv, "-64")) {
+            ap = NATIVE_64;
+            if(!ap) {
+                unrecognizednative64seen = true;
+                continue;
+            }
+        } else if(MATCHARG(argv, "-c")) {
+            free(envCopy);
+            envCopy = _copyenv(NULL); // create empty environment
+            if(!envCopy)
+                errx(1, "Out of memory processing -c");
+            continue;
+        } else if((ret = MATCHARGWITHVALUE(argv, "-d", 2, "-d without envname"))) {
+            MAKEENVCOPY("Out of memory processing -d");
+            _unsetenvp(ret, &envCopy, NULL);
+            continue;
+        } else if((ret = MATCHARGWITHVALUE(argv, "-e", 2, "-e without envname=value"))) {
+            MAKEENVCOPY("Out of memory processing -e");
+            const char *cp = strchr(ret, '=');
+            if(!cp) {
+                warnx("-e %s: no equal sign", ret);
+                usage(1);
+            }
+            cp++; // skip to value
+            /*
+             * _setenvp() only uses the name before any equal sign found in
+             * the first argument.
+             */
+            _setenvp(ret, cp, 1, &envCopy, NULL);
+            continue;
+        } else if(MATCHARG(argv, "-h")) {
+            usage(0);
+        } else {
+            ap = *argv + 1;
+            if(*ap == '-') ap++;
+        }
+        addCPUbyname(cpu, ap);
     }
-  progname = get_progname(argv[0]);
-  if (strcmp (progname,ARCH_PROG) == 0) {
-    arch = NXGetArchInfoFromCpuType(arch->cputype, CPU_SUBTYPE_MULTIPLE);
-    if (arch == NULL)
-    {
-	fprintf (stderr,"Unknown architecture.\n");
-	exit(-1);
+    if(cpu->errs)
+        exit(1);
+    if(!*argv || !**argv) {
+        warnx("No command to execute");
+        usage(1);
     }
-  }
-  else if (strcmp (progname,MACHINE_PROG) == 0)
-    ;
-  else
-    {
-      fprintf 
-	(stderr,"*error: This program must be named either %s or %s\n",ARCH_PROG,MACHINE_PROG);
-      exit (-1);
+    /* if the program is already a link to arch, then force execpath */
+    int needexecpath = wrapped(*argv);
+
+    /*
+     * If we don't have any architecutures, try ARCHPREFERENCE and plist
+     * files.
+     */
+    if((cpu->count == 0) || needexecpath)
+        spawnFromPreferences(cpu, needexecpath, argv); /* doesn't return */
+
+    /*
+     * Call posix_spawnp on the program name.
+     */
+    spawnIt(cpu, 1, *argv, argv);
+}
+
+
+/* the main() routine */
+int
+main(int argc, char **argv)
+{
+    const char *prog = getprogname();
+    int my_name_is_arch;
+    CPU cpu;
+
+    if(strcmp(prog, MACHINE_PROG) == 0) {
+        if(argc > 1)
+            errx(-1, "no arguments accepted");
+        arch(0); /* the "machine" command was called */
+    } else if((my_name_is_arch = (strcmp(prog, ARCH_PROG) == 0))) {
+        if(argc == 1)
+            arch(1); /* the "arch" command with no arguments was called */
     }
-  if (!isatty(fileno(stdin)))
-    printf("%s", arch->name);
-  else
-    printf ("%s\n", arch->name);
-    return 0;
+
+    initCPU(&cpu);
+
+    if(my_name_is_arch)
+        spawnFromArgs(&cpu, argv);
+    else
+        spawnFromPreferences(&cpu, 1, argv);
+
+    /* should never get here */
+    errx(1, "returned from spawn");
 }