Rewrite faketime shell script in C

1 files changed, 148 insertions, 941 deletions

diff --git a/src/faketime.c b/src/faketime.c
index c374a2a..3f6fdb2 100644
--- a/src/faketime.c
+++ b/src/faketime.c
@@ -1,958 +1,165 @@
-/*
- *  This file is part of the FakeTime Preload Library, version 0.8.
- *
- *  The FakeTime Preload Library is free software; you can redistribute it
- *  and/or modify it under the terms of the GNU General Public License v2 as
- *  published by the Free Software Foundation.
+/**
+ * Faketime binary spawning commands with FTPL (faketime preload library).
  *
- *  The FakeTime Preload Library is distributed in the hope that it will
- *  be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
- *  of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
+ * TODO: fill propery formated credits and license
+ * Converted from shell script with the following credits and comments:
  *
- *  You should have received a copy of the GNU General Public License v2
- *  along with the FakeTime Preload Library; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- */
+ * Thanks to Daniel Kahn Gillmor for improvement suggestions.
+
+ * It allows you to modify the date and time a program sees when using
+ * system library calls such as time() and fstat().
 
+ * This wrapper exposes only a small subset of the FTPL functionality.
+ * Please see FTPL's README file for more details
 
-#define _GNU_SOURCE             /* required to get RTLD_NEXT defined */
-#define _XOPEN_SOURCE           /* required to get strptime() defined */
+ * Acknowledgment: Parts of the functionality of this wrapper have been
+ * inspired by Matthias Urlichs' datefudge 1.14.
+
+ * Compile time configuration: Path where the libfaketime libraries can be found
+ * on Linux/UNIX . */
 
 #include <stdio.h>
+#include <unistd.h>
 #include <stdlib.h>
-#include <time.h>
+#include <stdbool.h>
 #include <string.h>
+#include <time.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 
-/* pthread-handling contributed by David North, TDI in version 0.7 */
-#ifdef PTHREAD
-#include <pthread.h>
-
-static pthread_mutex_t once_mutex=PTHREAD_MUTEX_INITIALIZER;
-
-#define SINGLE_IF_MTX(ifcondition,mtxaddr) \
-  if (ifcondition) { \
-    pthread_mutex_lock(mtxaddr); \
-    pthread_cleanup_push((void (*)(void *))pthread_mutex_unlock, (void *)mtxaddr); \
-    if (ifcondition) {
-#define SINGLE_IF(ifcondition) SINGLE_IF_MTX(ifcondition,&once_mutex)
-#define END_SINGLE_IF \
-    } \
-    pthread_cleanup_pop(1); \
-  }
-
-#else
-
-#define SINGLE_IF_MTX(ifcondition,mtxaddr) if (ifcondition) {
-#define SINGLE_IF(ifcondition) if (ifcondition) {
-#define END_SINGLE_IF }
-
-#endif
-
-#include <sys/timeb.h>
-#include <dlfcn.h>
-
-#define BUFFERLEN   256
-
-/* prototypes */
-time_t fake_time(time_t *time_tptr);
-int    fake_ftime(struct timeb *tp);
-int    fake_gettimeofday(struct timeval *tv, void *tz);
-#ifdef POSIX_REALTIME
-int    fake_clock_gettime(clockid_t clk_id, struct timespec *tp);
-#endif
-
-/*
- * Intercepted system calls:
- *  - time()
- *  - ftime()
- *  - gettimeofday()
- *  - clock_gettime()
- *
- *  Since version 0.7, if FAKE_INTERNAL_CALLS is defined, also calls to
- *  __time(), __ftime(), __gettimeofday(), and __clock_gettime() will be
- *  intercepted.
- *
- *  Thanks to a contribution by Philipp Hachtmann, the following
- *  system calls will also be time-adjusted depending on the compile
- *  switches used + any environmental variables present.
- *
- *  - stat()
- *  - fstat()
- *  - lstat()
- *  - the 64-bit versions of those three
- *
- */
-
-#ifdef FAKE_STAT
-
-#ifndef NO_ATFILE
-#ifndef _ATFILE_SOURCE
-#define _ATFILE_SOURCE
-#endif
-#include <fcntl.h> /* Definition of AT_* constants */
-#endif
-
-#include <sys/stat.h>
-
-static int fake_stat_disabled = 0;
-
-/**
- * When advancing time linearly with each time(), etc. call, the calls are
- * counted here */
-static long int ticks = 0;
-
-/* Contributed by Philipp Hachtmann in version 0.6 */
-int __xstat (int ver, const char *path, struct stat *buf) {
-  static int (*real_stat) (int, const char *, struct stat *);
-  static int has_real_stat=0;
-
-  SINGLE_IF(has_real_stat==0)
-    real_stat = NULL;
-    real_stat = dlsym(RTLD_NEXT, "__xstat");
-    if (dlerror() == NULL) {
-      has_real_stat = 1;
-    }
-  END_SINGLE_IF
-  if (!has_real_stat) {  /* dlsym() failed */
-#ifdef DEBUG
-    (void) fprintf(stderr, "faketime problem: original stat() not found.\n");
-#endif
-    return -1; /* propagate error to caller */
-  }
-
-  int result = real_stat(ver, path, buf);
-  if (result == -1) {
-    return -1;
-  }
-
-   if (buf != NULL) {
-     if (!fake_stat_disabled) {
-       buf->st_ctime = fake_time(&(buf->st_ctime));
-       buf->st_atime = fake_time(&(buf->st_atime));
-       buf->st_mtime = fake_time(&(buf->st_mtime));
-     }
-   }
-
-  return result;
-}
-
-/* Contributed by Philipp Hachtmann in version 0.6 */
-int __fxstat (int ver, int fildes, struct stat *buf) {
-  static int (*real_fstat) (int, int, struct stat *);
-  static int has_real_fstat=0;
-
-  SINGLE_IF(has_real_fstat==0)
-    real_fstat = NULL;
-    real_fstat = dlsym(RTLD_NEXT, "__fxstat");
-    if (dlerror() == NULL) {
-      has_real_fstat = 1;
-    }
-  END_SINGLE_IF
-  if (!has_real_fstat) {  /* dlsym() failed */
-#ifdef DEBUG
-    (void) fprintf(stderr, "faketime problem: original fstat() not found.\n");
-#endif
-    return -1; /* propagate error to caller */
-  }
-
-  int result = real_fstat(ver, fildes, buf);
-  if (result == -1) {
-    return -1;
-  }
-
-  if (buf != NULL) {
-    if (!fake_stat_disabled) {
-      buf->st_ctime = fake_time(&(buf->st_ctime));
-      buf->st_atime = fake_time(&(buf->st_atime));
-      buf->st_mtime = fake_time(&(buf->st_mtime));
-    }
-  }
-  return result;
-}
-
-/* Added in v0.8 as suggested by Daniel Kahn Gillmor */
-#ifndef NO_ATFILE
-int __fxstatat(int ver, int fildes, const char *filename, struct stat *buf, int flag) {
-  static int (*real_fstatat) (int, int, const char *, struct stat *, int);
-  static int has_real_fstatat=0;
-
-  SINGLE_IF(has_real_fstatat==0)
-    real_fstatat = NULL;
-    real_fstatat = dlsym(RTLD_NEXT, "__fxstatat");
-    if (dlerror() == NULL) {
-      has_real_fstatat = 1;
-    }
-  END_SINGLE_IF
-  if (!has_real_fstatat) {  /* dlsym() failed */
-#ifdef DEBUG
-    (void) fprintf(stderr, "faketime problem: original fstatat() not found.\n");
-#endif
-    return -1; /* propagate error to caller */
-  }
-
-  int result = real_fstatat(ver, fildes, filename, buf, flag);
-  if (result == -1) {
-    return -1;
-  }
-
-  if (buf != NULL) {
-    if (!fake_stat_disabled) {
-      buf->st_ctime = fake_time(&(buf->st_ctime));
-      buf->st_atime = fake_time(&(buf->st_atime));
-      buf->st_mtime = fake_time(&(buf->st_mtime));
-    }
-  }
-  return result;
-}
-#endif
-
-/* Contributed by Philipp Hachtmann in version 0.6 */
-int __lxstat (int ver, const char *path, struct stat *buf) {
-  static int (*real_lstat)(int, const char *, struct stat *);
-  static int has_real_lstat=0;
-
-  SINGLE_IF(has_real_lstat==0)
-    real_lstat = NULL;
-    real_lstat = dlsym(RTLD_NEXT, "__lxstat");
-    if (dlerror() == NULL) {
-      has_real_lstat = 1;
-    }
-  END_SINGLE_IF
-  if (!has_real_lstat) {  /* dlsym() failed */
-#ifdef DEBUG
-    (void) fprintf(stderr, "faketime problem: original lstat() not found.\n");
-#endif
-    return -1; /* propagate error to caller */
-  }
-
-  int result = real_lstat(ver, path, buf);
-  if (result == -1) {
-    return -1;
-  }
-
-  if (buf != NULL) {
-    if (!fake_stat_disabled) {
-      buf->st_ctime = fake_time(&(buf->st_ctime));
-      buf->st_atime = fake_time(&(buf->st_atime));
-      buf->st_mtime = fake_time(&(buf->st_mtime));
-    }
-  }
-  return result;
-}
-
-/* Contributed by Philipp Hachtmann in version 0.6 */
-int __xstat64 (int ver, const char *path, struct stat64 *buf) {
-  static int (*real_stat) (int, const char *, struct stat64 *);
-  static int has_real_stat = 0;
-
-  SINGLE_IF(has_real_stat==0)
-    real_stat = NULL;
-    real_stat = dlsym(RTLD_NEXT,"__xstat64");
-    if (dlerror() == NULL) {
-      has_real_stat = 1;
-    }
-  END_SINGLE_IF
-  if (!has_real_stat) {  /* dlsym() failed */
-#ifdef DEBUG
-    (void) fprintf(stderr, "faketime problem: original stat() not found.\n");
-#endif
-    return -1; /* propagate error to caller */
-  }
-
-  int result=real_stat(ver, path, buf);
-  if (result == -1) {
-    return -1;
-  }
-
-  if (buf != NULL){
-    if (!fake_stat_disabled) {
-      buf->st_ctime = fake_time(&(buf->st_ctime));
-      buf->st_atime = fake_time(&(buf->st_atime));
-      buf->st_mtime = fake_time(&(buf->st_mtime));
-    }
-  }
-  return result;
-}
-
-/* Contributed by Philipp Hachtmann in version 0.6 */
-int __fxstat64 (int ver, int fildes, struct stat64 *buf) {
-  static int (*real_fstat)(int, int , struct stat64 *);
-  static int has_real_fstat=0;
-
-  SINGLE_IF(has_real_fstat==0)
-    real_fstat = NULL;
-    real_fstat = dlsym(RTLD_NEXT, "__fxstat64");
-    if (dlerror() == NULL) {
-      has_real_fstat = 1;
-    }
-  END_SINGLE_IF
-  if (!has_real_fstat) {  /* dlsym() failed */
-#ifdef DEBUG
-    (void) fprintf(stderr, "faketime problem: original fstat() not found.\n");
-#endif
-    return -1; /* propagate error to caller */
-  }
-
-  int result = real_fstat(ver, fildes, buf);
-  if (result == -1){
-    return -1;
-  }
-
-  if (buf != NULL){
-    if (!fake_stat_disabled) {
-      buf->st_ctime = fake_time(&(buf->st_ctime));
-      buf->st_atime = fake_time(&(buf->st_atime));
-      buf->st_mtime = fake_time(&(buf->st_mtime));
-    }
-  }
-  return result;
-}
-
-/* Added in v0.8 as suggested by Daniel Kahn Gillmor */
-#ifndef NO_ATFILE
-int __fxstatat64 (int ver, int fildes, const char *filename, struct stat64 *buf, int flag) {
-  static int (*real_fstatat64)(int, int , const char *, struct stat64 *, int);
-  static int has_real_fstatat64=0;
-
-  SINGLE_IF(has_real_fstatat64==0)
-    real_fstatat64 = NULL;
-    real_fstatat64 = dlsym(RTLD_NEXT, "__fxstatat64");
-    if (dlerror() == NULL) {
-      has_real_fstatat64 = 1;
-    }
-  END_SINGLE_IF
-  if (!has_real_fstatat64) {  /* dlsym() failed */
-#ifdef DEBUG
-    (void) fprintf(stderr, "faketime problem: original fstatat64() not found.\n");
-#endif
-    return -1; /* propagate error to caller */
-  }
-
-  int result = real_fstatat64(ver, fildes, filename, buf, flag);
-  if (result == -1){
-    return -1;
-  }
-
-  if (buf != NULL){
-    if (!fake_stat_disabled) {
-      buf->st_ctime = fake_time(&(buf->st_ctime));
-      buf->st_atime = fake_time(&(buf->st_atime));
-      buf->st_mtime = fake_time(&(buf->st_mtime));
-    }
-  }
-  return result;
-}
-#endif
-
-/* Contributed by Philipp Hachtmann in version 0.6 */
-int __lxstat64 (int ver, const char *path, struct stat64 *buf){
-  static int (*real_lstat) (int, const char *, struct stat64 *);
-  static int has_real_lstat = 0;
-
-  SINGLE_IF(has_real_lstat==0)
-    real_lstat = NULL;
-    real_lstat = dlsym(RTLD_NEXT, "__lxstat64");
-    if (dlerror() == NULL) {
-      has_real_lstat = 1;
-    }
-  END_SINGLE_IF
-  if (!has_real_lstat) {  /* dlsym() failed */
-#ifdef DEBUG
-    (void) fprintf(stderr, "faketime problem: original lstat() not found.\n");
-#endif
-    return -1; /* propagate error to caller */
-  }
-
-  int result = real_lstat(ver, path, buf);
-  if (result == -1){
-    return -1;
-  }
-
-  if (buf != NULL){
-    if (!fake_stat_disabled) {
-      buf->st_ctime = fake_time(&(buf->st_ctime));
-      buf->st_atime = fake_time(&(buf->st_atime));
-      buf->st_mtime = fake_time(&(buf->st_mtime));
-    }
-  }
-  return result;
-}
-#endif
-
-/*
- * On MacOS, time() internally uses gettimeofday. If we don't
- * break the cycle by just calling it directly, we double-apply
- * relative changes.
- */
+const char version[] = "0.8";
 
 #ifdef __APPLE__
-static int (*real_gettimeofday)(struct timeval *, void *);
-static int has_real_gettimeofday = 0;
-#endif
-/*
- *  Our version of time() allows us to return fake values, so the calling
- *  program thinks it's retrieving the current date and time, while it is
- *  not
- *  Note that this routine is split into two parts so that the initialization
- *  piece can call the 'real' time function to establish a base time.
- */
-static time_t _ftpl_time(time_t *time_tptr) {
-#ifdef __APPLE__
-    struct timeval tvm, *tv = &tvm;
+static const char *date_cmd = "gdate";
 #else
-    static time_t (*real_time)(time_t *);
-    static int has_real_time = 0;
-#endif
-
-    time_t result;
-
-    time_t null_dummy;
-
-    /* Handle null pointers correctly, fix as suggested by Andres Ojamaa */
-    if (time_tptr == NULL) {
-        time_tptr = &null_dummy;
-        /* (void) fprintf(stderr, "NULL pointer caught in time().\n"); */
-    }
-
+static const char *date_cmd = "date";
+#endif
+
+void usage(const char *name) {
+  printf("\n");
+  printf("Usage: %s [switches] <timestamp> <program with arguments>\n", name);
+  printf("\n");
+  printf("This will run the specified 'program' with the given 'arguments'.\n");
+  printf("The program will be tricked into seeing the given 'timestamp' as its starting date and time.\n");
+  printf("The clock will continue to run from this timestamp. Please see the manpage (man faketime)\n");
+  printf("for advanced options, such as stopping the wall clock and make it run faster or slower.\n");
+  printf("\n");
+  printf("The optional switches are:\n");
+  printf("  -m        : Use the multi-threaded version of libfaketime\n");
+  printf("  -f        : Use the advanced timestamp specification format (see manpage)\n");
+  printf("\n");
+  printf("Examples:\n");
+  printf("%s 'last friday 5 pm' /bin/date\n", name);
+  printf("%s '2008-12-24 08:15:42' /bin/date\n", name);
+  printf("%s -f '+2,5y x10,0' /bin/bash -c 'date; while true; do echo $SECONDS ; sleep 1 ; done'\n", name);
+  printf("%s -f '+2,5y x0,50' /bin/bash -c 'date; while true; do echo $SECONDS ; sleep 1 ; done'\n", name);
+  printf("%s -f '+2,5y i2,0' /bin/bash -c 'date; while true; do echo $SECONDS ; sleep 1 ; done'\n", name);
+  printf("(Please note that it depends on your locale settings whether . or , has to be used for fractions)\n");
+  printf("\n");
+
+}
+
+int main (int argc, char **argv)
+{
+  int curr_opt = 1;
+  bool use_mt = false, use_direct = false;
+  int pfds[2];
+  long offset;
+
+  while(curr_opt < argc) {
+    if (0 == strcmp(argv[curr_opt], "-m")) {
+      use_mt = true;
+      curr_opt++;
+      continue;
+    } else if (0 == strcmp(argv[curr_opt], "-f")) {
+      use_direct = true;
+      curr_opt++;
+      continue;
+    } else if ((0 == strcmp(argv[curr_opt], "-v")) ||
+	       (0 == strcmp(argv[curr_opt], "--version"))) {
+      printf("\n%s: Version %s\n"
+	     "For usage information please use '%s --help\n'.",
+	     argv[0], version, argv[0]);
+      exit(EXIT_SUCCESS);
+    } else if ((0 == strcmp(argv[curr_opt], "-h")) ||
+	       (0 == strcmp(argv[curr_opt], "-?")) ||
+	       (0 == strcmp(argv[curr_opt], "--help"))) {
+      usage(argv[0]);
+      exit(EXIT_SUCCESS);
+    } else {
+      /* we parsed all options */
+      break;
+    }
+  }
+
+  /* we need at least a timestamp string and a command to run */
+  if (argc - curr_opt < 2) {
+    usage(argv[0]);
+    exit(EXIT_FAILURE);
+  }
+
+  if (!use_direct) {
+    // TODO get seconds
+    pipe(pfds);
+    pid_t pid;
+    int ret = EXIT_SUCCESS;
+
+    if (0 == (pid = fork())) {
+      close(1);       /* close normal stdout */
+      dup(pfds[1]);   /* make stdout same as pfds[1] */
+      close(pfds[0]); /* we don't need this */
+      if (EXIT_SUCCESS != execlp(date_cmd, date_cmd, "-d", argv[curr_opt], "+%s",(char *) NULL)) {
+	perror("Running (g)date failed");
+	exit(EXIT_FAILURE);
+      }
+    } else {
+      char buf[256] = {0}; /* e will have way less than 256 digits */
+      close(pfds[1]);   /* we won't write to this */
+      read(pfds[0], buf, 256);
+      waitpid(pid, &ret, 0);
+      if (ret != EXIT_SUCCESS) {
+	printf("Error: Timestamp to fake not recognized, please re-try with a "
+	       "different timestamp.\n");
+	exit(EXIT_FAILURE);
+      }
+      offset = atol(buf) - time(NULL);
+      ret = snprintf(buf, sizeof(buf), "%s%ld", (offset >= 0)?"+":"", offset);
+      setenv("FAKETIME", buf, true);
+    }
+  } else {
+    /* simply pass format string along */
+    setenv("FAKETIME", argv[curr_opt], true);
+  }
+
+  /* we just consumed the timestamp option */
+  curr_opt++;
+
+  {
+    char *ftpl_path;  
 #ifdef __APPLE__
-    /* Check whether we've got a pointer to the real ftime() function yet */
-    SINGLE_IF(has_real_gettimeofday==0)
-        real_gettimeofday = NULL;
-        real_gettimeofday = dlsym(RTLD_NEXT, "gettimeofday");
-
-        /* check whether dlsym() worked */
-        if (dlerror() == NULL) {
-            has_real_gettimeofday = 1;
-        }
-    END_SINGLE_IF
-    if (!has_real_gettimeofday) {  /* dlsym() failed */
-#ifdef DEBUG
-            (void) fprintf(stderr, "faketime problem: original gettimeofday() not found.\n");
-#endif
-            return -1; /* propagate error to caller */
-    }
-
-    /* initialize our result with the real current time */
-    result = (*real_gettimeofday)(tv, NULL);
-    if (result == -1) return result; /* original function failed */
-    if (time_tptr != NULL)
-        *time_tptr = tv->tv_sec;
-    result = tv->tv_sec;
+    ftpl_path = PREFIX "/libfaketime.dylib.1";
+    setenv("DYLD_INSERT_LIBRARIES", ftpl_path, true);
+    setenv("DYLD_FORCE_FLAT_NAMESPACE", "1", true);
 #else
-    /* Check whether we've got a pointer to the real time function yet */
-    SINGLE_IF(has_real_time==0)
-        real_time = NULL;
-        real_time = dlsym(RTLD_NEXT, "time");
-
-        /* check whether dlsym() worked */
-        if (dlerror() == NULL) {
-            has_real_time = 1;
-        }
-    END_SINGLE_IF
-    if (!has_real_time) {  /* dlsym() failed */
-#ifdef DEBUG
-            (void) fprintf(stderr, "faketime problem: original time() not found.\n");
-#endif
-            if (time_tptr != NULL)
-                *time_tptr = -1;
-            return -1; /* propagate error to caller */
-    }
-
-    /* initialize our result with the real current time */
-    result = (*real_time)(time_tptr);
-#endif
-
-    return result;
-}
-
-time_t time(time_t *time_tptr) {
-    time_t result;
-    time_t null_dummy;
-    if (time_tptr == NULL) {
-        time_tptr = &null_dummy;
-        /* (void) fprintf(stderr, "NULL pointer caught in time().\n"); */
-    }
-    result = _ftpl_time(time_tptr);
-    if (result == ((time_t) -1)) return result;
-
-    /* pass the real current time to our faking version, overwriting it */
-    result = fake_time(time_tptr);
-
-    /* return the result to the caller */
-    return result;
-}
-
-
-int ftime(struct timeb *tp) {
-    static int (*real_ftime)(struct timeb *);
-    static int has_real_ftime = 0;
-    int result;
-
-    /* sanity check */
-    if (tp == NULL)
-        return 0;               /* ftime() always returns 0, see manpage */
-
-    /* Check whether we've got a pointer to the real ftime() function yet */
-    SINGLE_IF(has_real_ftime==0)
-        real_ftime = NULL;
-        real_ftime = dlsym(RTLD_NEXT, "ftime");
-
-        /* check whether dlsym() worked */
-        if (dlerror() == NULL) {
-            has_real_ftime = 1;
-        }
-    END_SINGLE_IF
-    if (!has_real_ftime) {  /* dlsym() failed */
-#ifdef DEBUG
-            (void) fprintf(stderr, "faketime problem: original ftime() not found.\n");
-#endif
-            tp = NULL;
-            return 0; /* propagate error to caller */
-    }
-
-    /* initialize our result with the real current time */
-    result = (*real_ftime)(tp);
-
-    /* pass the real current ftime to our faking version, overwriting it */
-    result = fake_ftime(tp);
-
-    /* return the result to the caller */
-    return result; /* will always be 0 (see manpage) */
-}
-
-int gettimeofday(struct timeval *tv, void *tz) {
-#ifndef __APPLE__
-    static int (*real_gettimeofday)(struct timeval *, void *);
-    static int has_real_gettimeofday = 0;
-#endif
-    int result;
-
-    /* sanity check */
-    if (tv == NULL) {
-        return -1;
-    }
-
-    /* Check whether we've got a pointer to the real ftime() function yet */
-    SINGLE_IF(has_real_gettimeofday==0)
-        real_gettimeofday = NULL;
-        real_gettimeofday = dlsym(RTLD_NEXT, "gettimeofday");
-
-        /* check whether dlsym() worked */
-        if (dlerror() == NULL) {
-            has_real_gettimeofday = 1;
-        }
-    END_SINGLE_IF
-    if (!has_real_gettimeofday) {  /* dlsym() failed */
-#ifdef DEBUG
-            (void) fprintf(stderr, "faketime problem: original gettimeofday() not found.\n");
-#endif
-            return -1; /* propagate error to caller */
-    }
-
-    /* initialize our result with the real current time */
-    result = (*real_gettimeofday)(tv, tz);
-    if (result == -1) return result; /* original function failed */
-
-    /* pass the real current time to our faking version, overwriting it */
-    result = fake_gettimeofday(tv, tz);
-
-    /* return the result to the caller */
-    return result;
-}
-
-#ifdef POSIX_REALTIME
-int clock_gettime(clockid_t clk_id, struct timespec *tp) {
-    static int (*real_clock_gettime)(clockid_t clk_id, struct timespec *tp);
-    static int has_real_clock_gettime = 0;
-    int result;
-
-    /* sanity check */
-    if (tp == NULL) {
-        return -1;
-    }
-
-    /* Check whether we've got a pointer to the real clock_gettime() function yet */
-    SINGLE_IF(has_real_clock_gettime==0)
-        real_clock_gettime = NULL;
-        real_clock_gettime = dlsym(RTLD_NEXT, "clock_gettime");
-
-        /* check whether dlsym() worked */
-        if (dlerror() == NULL) {
-            has_real_clock_gettime = 1;
-        }
-    END_SINGLE_IF
-    if (!has_real_clock_gettime) {  /* dlsym() failed */
-#ifdef DEBUG
-            (void) fprintf(stderr, "faketime problem: original clock_gettime() not found.\n");
-#endif
-            return -1; /* propagate error to caller */
-    }
-
-    /* initialize our result with the real current time */
-    result = (*real_clock_gettime)(clk_id, tp);
-    if (result == -1) return result; /* original function failed */
-
-    /* pass the real current time to our faking version, overwriting it */
-    result = fake_clock_gettime(clk_id, tp);
-
-    /* return the result to the caller */
-    return result;
-}
-#endif
-
-/*
- *  Static time_t to store our startup time, followed by a load-time library
- *  initialization declaration.
- */
-static time_t ftpl_starttime = 0;
-
-void __attribute__ ((constructor)) ftpl_init(void)
-{
-    time_t temp_tt;
-
-#ifdef FAKE_STAT
-    if (getenv("NO_FAKE_STAT")!=NULL) {
-      fake_stat_disabled = 1;  //Note that this is NOT re-checked
-    }
-#endif
-
-    ftpl_starttime = _ftpl_time(&temp_tt);
-}
-
-static void remove_trailing_eols(char *line)
-{
-	char *endp = line + strlen(line);
-	/*
-	 * erase the last char if it's a newline
-	 * or carriage return, and back up.
-	 * keep doing this, but don't back up
-	 * past the beginning of the string.
-	 */
-# define is_eolchar(c) ((c) == '\n' || (c) == '\r')
-	while (endp > line && is_eolchar(endp[-1]))
-		*--endp = '\0';
-}
-
-
-time_t fake_time(time_t *time_tptr) {
-    static char user_faked_time[BUFFERLEN]; /* changed to static for caching in v0.6 */
-    struct tm user_faked_time_tm;
-    time_t user_faked_time_time_t;
-    long user_offset;
-    double frac_user_offset;
-    char filename[BUFSIZ], line[BUFFERLEN];
-    FILE *faketimerc;
-    static const char *user_faked_time_fmt = NULL;
-    char * tmp_time_fmt;
-
-    /* variables used for caching, introduced in version 0.6 */
-    static time_t last_data_fetch = 0;  /* not fetched previously at first call */
-    static int cache_expired = 1;       /* considered expired at first call */
-    static int cache_duration = 10;     /* cache fake time input for 10 seconds */
-
-#ifdef LIMITEDFAKING
-    static long callcounter = 0;
-    static int limited_initialized = 0;
-    char envvarbuf[32];
-    static long FAKETIME_START_AFTER_SECONDS = -1;
-    static long FAKETIME_STOP_AFTER_SECONDS = -1;
-    static long FAKETIME_START_AFTER_NUMCALLS = -1;
-    static long FAKETIME_STOP_AFTER_NUMCALLS = -1;
-#endif
-
-#ifdef SPAWNSUPPORT
-    static int spawned = 0;
-    static long spawn_callcounter = 0;
-    static int spawn_initialized = 0;
-    char spawn_envvarbuf[32];
-    static char FAKETIME_SPAWN_TARGET[1024];
-    static long FAKETIME_SPAWN_SECONDS = -1;
-    static long FAKETIME_SPAWN_NUMCALLS = -1;
-#endif
-
-/*
- * This no longer appears to be necessary in Mac OS X 10.7 Lion
- */
-//#ifdef __APPLE__
-//    static int malloc_arena = 0;
-//#endif
-
-#ifdef PTHREAD_SINGLETHREADED_TIME
-static pthread_mutex_t time_mutex=PTHREAD_MUTEX_INITIALIZER;
-    pthread_mutex_lock(&time_mutex);
-    pthread_cleanup_push((void (*)(void *))pthread_mutex_unlock, (void *)&time_mutex);
-#endif
-
-    /* Sanity check by Karl Chan since v0.8 */
-    if (time_tptr == NULL) return -1;
-
-#ifdef LIMITEDFAKING
-    /* Check whether we actually should be faking the returned timestamp. */
-
-    if (ftpl_starttime > 0) {
-        if (limited_initialized == 0) {
-            if (getenv("FAKETIME_START_AFTER_SECONDS") != NULL) {
-                (void) strncpy(envvarbuf, getenv("FAKETIME_START_AFTER_SECONDS"), 30);
-                FAKETIME_START_AFTER_SECONDS = atol(envvarbuf);
-            }
-            if (getenv("FAKETIME_STOP_AFTER_SECONDS") != NULL) {
-                (void) strncpy(envvarbuf, getenv("FAKETIME_STOP_AFTER_SECONDS"), 30);
-                FAKETIME_STOP_AFTER_SECONDS = atol(envvarbuf);
-            }
-            if (getenv("FAKETIME_START_AFTER_NUMCALLS") != NULL) {
-                (void) strncpy(envvarbuf, getenv("FAKETIME_START_AFTER_NUMCALLS"), 30);
-                FAKETIME_START_AFTER_NUMCALLS = atol(envvarbuf);
-            }
-            if (getenv("FAKETIME_STOP_AFTER_NUMCALLS") != NULL) {
-                (void) strncpy(envvarbuf, getenv("FAKETIME_STOP_AFTER_NUMCALLS"), 30);
-                FAKETIME_STOP_AFTER_NUMCALLS = atol(envvarbuf);
-            }
-            limited_initialized = 1;
-        }
-        if ((callcounter + 1) >= callcounter) callcounter++;
-
-        /* For debugging, output #seconds and #calls */
-        /* fprintf(stderr, "(libfaketime limits -> runtime: %lu, callcounter: %lu\n", (*time_tptr - ftpl_starttime), callcounter); */
-        if ((FAKETIME_START_AFTER_SECONDS != -1) && ((*time_tptr - ftpl_starttime) < FAKETIME_START_AFTER_SECONDS)) return *time_tptr;
-        if ((FAKETIME_STOP_AFTER_SECONDS != -1) && ((*time_tptr - ftpl_starttime) >= FAKETIME_STOP_AFTER_SECONDS)) return *time_tptr;
-        if ((FAKETIME_START_AFTER_NUMCALLS != -1) && (callcounter < FAKETIME_START_AFTER_NUMCALLS)) return *time_tptr;
-        if ((FAKETIME_STOP_AFTER_NUMCALLS != -1) && (callcounter >= FAKETIME_STOP_AFTER_NUMCALLS)) return *time_tptr;
-        /* fprintf(stderr, "(libfaketime limits -> runtime: %lu, callcounter: %lu continues\n", (*time_tptr - ftpl_starttime), callcounter); */
-
-    }
-#endif
-
-#ifdef SPAWNSUPPORT
-    /* check whether we should spawn an external command */
-
-    if (ftpl_starttime > 0) {
-
-        if(spawn_initialized == 0) {
-            if (getenv("FAKETIME_SPAWN_TARGET") != NULL) {
-                (void) strncpy(FAKETIME_SPAWN_TARGET, getenv("FAKETIME_SPAWN_TARGET"), 1024);
-
-                if (getenv("FAKETIME_SPAWN_SECONDS") != NULL) {
-                    (void) strncpy(spawn_envvarbuf, getenv("FAKETIME_SPAWN_SECONDS"), 30);
-                    FAKETIME_SPAWN_SECONDS = atol(spawn_envvarbuf);
-                }
-
-                if (getenv("FAKETIME_SPAWN_NUMCALLS") != NULL) {
-                    (void) strncpy(spawn_envvarbuf, getenv("FAKETIME_SPAWN_NUMCALLS"), 30);
-                    FAKETIME_SPAWN_NUMCALLS = atol(spawn_envvarbuf);
-                }
-            }
-            spawn_initialized = 1;
-        }
-
-        if (spawned == 0) { /* exec external command once only */
-            if ((spawn_callcounter + 1) >= spawn_callcounter) spawn_callcounter++;
-            if ((((*time_tptr - ftpl_starttime) == FAKETIME_SPAWN_SECONDS) || (spawn_callcounter == FAKETIME_SPAWN_NUMCALLS)) && (spawned == 0)) {
-                spawned = 1;
-                system(FAKETIME_SPAWN_TARGET);
-            }
-
-        }
-
+    {
+      char *ld_preload_new, *ld_preload = getenv("LD_PRELOAD");
+      size_t len;
+      if (use_mt) {
+	ftpl_path = PREFIX "/lib/faketime/libfaketimeMT.so.1";
+      } else {
+	ftpl_path = PREFIX "/lib/faketime/libfaketime.so.1";
+      }
+      len = (ld_preload)?strlen(ld_preload):0 + 2 + strlen(ftpl_path);
+      ld_preload_new = malloc(len);
+      snprintf(ld_preload_new, len ,"%s%s%s", (ld_preload)?ld_preload:"",
+	       (ld_preload)?":":"", ftpl_path);
+      setenv("LD_PRELOAD", ld_preload_new, true);
+      free(ld_preload_new);
     }
 #endif
-
-
-    if (last_data_fetch > 0) {
-        if ((*time_tptr - last_data_fetch) > cache_duration) {
-            cache_expired = 1;
-        }
-        else {
-            cache_expired = 0;
-        }
-    }
-
-#ifdef NO_CACHING
-    cache_expired = 1;
-#endif
-
-    if (cache_expired == 1) {
-
-        last_data_fetch = *time_tptr;
-
-        /* Can be enabled for testing ...
-        fprintf(stderr, "***************++ Cache expired ++**************\n");
-        */
-
-        /* initialize with default */
-        snprintf(user_faked_time, BUFFERLEN, "+0");
-
-        /* fake time supplied as environment variable? */
-        if (getenv("FAKETIME") != NULL) {
-                (void) strncpy(user_faked_time, getenv("FAKETIME"), BUFFERLEN-2);
-                user_faked_time[BUFFERLEN-1] = 0;
-        }
-        else {
-                /* check whether there's a .faketimerc in the user's home directory, or
-                * a system-wide /etc/faketimerc present.
-                * The /etc/faketimerc handling has been contributed by David Burley,
-                * Jacob Moorman, and Wayne Davison of SourceForge, Inc. in version 0.6 */
-                (void) snprintf(filename, BUFSIZ, "%s/.faketimerc", getenv("HOME"));
-                if ((faketimerc = fopen(filename, "rt")) != NULL ||
-                (faketimerc = fopen("/etc/faketimerc", "rt")) != NULL) {
-                while(fgets(line, BUFFERLEN, faketimerc) != NULL) {
-                        if ((strlen(line) > 1) && (line[0] != ' ') &&
-                        (line[0] != '#') && (line[0] != ';')) {
-                        remove_trailing_eols(line);
-                        strncpy(user_faked_time, line, BUFFERLEN-1);
-                        user_faked_time[BUFFERLEN-1] = 0;
-                        break;
-                        }
-                }
-                fclose(faketimerc);
-                }
-        } /* read fake time from file */
-
-
-        user_faked_time_fmt = getenv("FAKETIME_FMT");
-        if (user_faked_time_fmt == NULL)
-            user_faked_time_fmt = "%Y-%m-%d %T";
-
-    } /* cache had expired */
-
-/*
- * This no longer appears to be necessary in Mac OS X 10.7 Lion
- */
-//#ifdef __APPLE__
-//    SINGLE_IF(malloc_arena==0)
-//      malloc_arena = 1;
-//        return *time_tptr;
-//    END_SINGLE_IF
-//#endif
-
-    /* check whether the user gave us an absolute time to fake */
-    switch (user_faked_time[0]) {
-
-      default:  /* Try and interpret this as a specified time */
-        user_faked_time_tm.tm_isdst = -1;
-        (void) strptime(user_faked_time, user_faked_time_fmt, &user_faked_time_tm);
-
-        user_faked_time_time_t = mktime(&user_faked_time_tm);
-        if (user_faked_time_time_t != -1) {
-            if (time_tptr != NULL) /* sanity check */
-                *time_tptr = user_faked_time_time_t;
-        }
-        break;
-
-      case '+':
-      case '-': /* User-specified offset */
-        /* fractional time offsets contributed by Karl Chen in v0.8 */
-        frac_user_offset = atof(user_faked_time);
-
-        /* offset is in seconds by default, but the string may contain
-         * multipliers...
-         */
-        if (strchr(user_faked_time, 'm') != NULL) frac_user_offset *= 60;
-        else if (strchr(user_faked_time, 'h') != NULL) frac_user_offset *= 60 * 60;
-        else if (strchr(user_faked_time, 'd') != NULL) frac_user_offset *= 60 * 60 * 24;
-        else if (strchr(user_faked_time, 'y') != NULL) frac_user_offset *= 60 * 60 * 24 * 365;
-
-        /* Speed-up / slow-down contributed by Karl Chen in v0.8 */
-        if (strchr(user_faked_time, 'x') != NULL) {
-            const double rate = atof(strchr(user_faked_time, 'x')+1);
-            const long tdiff = (long long) *time_tptr - (long long)ftpl_starttime;
-            const double timeadj = tdiff * (rate - 1.0);
-            *time_tptr += (long) timeadj;
-        } else if (NULL != (tmp_time_fmt = strchr(user_faked_time, 'i'))) {
-	    /* increment time with every time() call*/
-            *time_tptr = atof(tmp_time_fmt + 1) * ticks++;
-        }
-
-        *time_tptr += (long) frac_user_offset;
-
-        break;
-
-      /* Contributed by David North, TDI in version 0.7 */
-      case '@': /* Specific time, but clock along relative to that starttime */
-        user_faked_time_tm.tm_isdst = -1;
-        (void) strptime(&user_faked_time[1], user_faked_time_fmt, &user_faked_time_tm);
-
-        user_faked_time_time_t = mktime(&user_faked_time_tm);
-        if (user_faked_time_time_t != -1) {
-            user_offset = - ( (long long int)ftpl_starttime - (long long int)user_faked_time_time_t );
-
-            /* Speed-up / slow-down contributed by Karl Chen in v0.8 */
-            if (strchr(user_faked_time, 'x') != NULL) {
-                const double rate = atof(strchr(user_faked_time, 'x')+1);
-                const long tdiff = (long long) *time_tptr - (long long)ftpl_starttime;
-                const double timeadj = tdiff * (rate - 1.0);
-                *time_tptr += (long) timeadj;
-            } else if (NULL != (tmp_time_fmt = strchr(user_faked_time, 'i'))) {
-                /* increment time with every time() call*/
-                *time_tptr = atof(tmp_time_fmt + 1) * ticks++;
-            }
-
-            *time_tptr += user_offset;
-        }
-        break;
-    }
-
-#ifdef PTHREAD_SINGLETHREADED_TIME
-    pthread_cleanup_pop(1);
-#endif
-
-    /* pass the possibly modified time back to caller */
-    return *time_tptr;
-}
-
-int fake_ftime(struct timeb *tp) {
-    time_t temp_tt = tp->time;
-
-    tp->time = fake_time(&temp_tt);
-
-    return 0; /* always returns 0, see manpage */
-}
-
-int fake_gettimeofday(struct timeval *tv, void *tz) {
-    time_t temp_tt = tv->tv_sec;
-
-    tv->tv_sec = fake_time(&temp_tt);
-
-    return 0;
-}
-
-#ifdef POSIX_REALTIME
-int fake_clock_gettime(clockid_t clk_id, struct timespec *tp) {
-    time_t temp_tt = tp->tv_sec;
-
-    /* Fake only if the call is realtime clock related */
-    if (clk_id == CLOCK_REALTIME) {
-        tp->tv_sec = fake_time(&temp_tt);
-    }
-
-    return 0;
-}
-#endif
-
-/*
- * This causes serious issues in Mac OS X 10.7 Lion and is disabled there
- */
-#ifndef __APPLE__
-/* Added in v0.7 as suggested by Jamie Cameron, Google */
-#ifdef FAKE_INTERNAL_CALLS
-int __gettimeofday(struct timeval *tv, void *tz) {
-    return gettimeofday(tv, tz);
-}
-
-#ifdef POSIX_REALTIME
-int __clock_gettime(clockid_t clk_id, struct timespec *tp) {
-    return clock_gettime(clk_id, tp);
-}
-#endif
-
-int __ftime(struct timeb *tp) {
-    return ftime(tp);
-}
-
-time_t __time(time_t *time_tptr) {
-    return time(time_tptr);
+  }
+  if (EXIT_SUCCESS != execvp(argv[curr_opt], &argv[curr_opt])) {
+    perror("Running specified command failed");
+    exit(EXIT_FAILURE);
+  }
 }
-#endif
-#endif
-
-/* eof */