NAME
       execve - execute program



SYNOPSIS
       #include <unistd.h>

       int  execve  (const  char  *filename, const char *argv [],
       const char *envp[]);



DESCRIPTION
       execve() executes the  program  pointed  to  by  filename.
       filename  must  be  either a binary executable, or a shell
       script starting with a line of the  form  "#!  interpreter
       [arg]".

       execve()  does  not return on success, and the text, data,
       bss, and stack of the calling process are  overwritten  by
       that  of the program loaded.  The program invoked inherits
       the calling process's PID, and any open  file  descriptors
       that are not set to close on exec.  Signals pending on the
       parent process are cleared.

       If the current program is being ptraced, a SIGTRAP is sent
       to it after a successful execve().



RETURN VALUE
       On  success,  execve()  does  not  return,  on error -1 is
       returned, and errno is set appropriately.



ERRORS
       EACCES The file is not a regular file.

       EACCES Execute permission is denied for the file.

       EPERM  The file system is mounted noexec.

       EPERM  The file system is mounted nosuid and the file  has
              an SUID or SGID bit set.

       E2BIG  The argument list is too big.

       ENOEXEC
              The magic number in the file is incorrect.

       EFAULT filename  points  outside  your  accessible address
              space.

       ENAMETOOLONG
              filename is too long.

       ENOENT The file does not exist.

       ENOMEM Insufficient kernel memory was available.

       ENOTDIR
              A component of the path prefix is not a  directory.

       EACCES Search  permission  is denied on a component of the
              path prefix.

       ELOOP  filename contains a circular reference (i.e., via a
              symbolic link)



CONFORMING TO
       SVID, AT&T, POSIX, X/OPEN, BSD 4.3



NOTES
       SUID  and  SGID  processes  can  not be ptrace()'d SUID or
       SGID.

       A maximum line length of 127 characters is allowed for the
       first  line  in a #! executable shell script.  This may be
       circumvented by changing the max size  of  buf,  in  which
       case  you  will  become  bound  by the 1024 byte size of a
       buffer, which is not easily worked around.



SEE ALSO
       execl(3), fork(2)