execve - execute program
int execve (const char *filename, char *const argv ,
char *const envp);
execve() executes the program pointed to by filename.
filename must be either a binary executable, or a script
starting with a line of the form "#! interpreter [arg]".
In the latter case, the interpreter must be a valid path
name for an executable which is not itself a script, which
will be invoked as interpreter [arg] filename.
argv is an array of argument strings passed to the new
program. envp is an array of strings, conventionally of
the form key=value, which are passed as environment to the
new program. Both, argv and envp must be terminated by a
null pointer. The argument vector and environment can be
accessed by the called program's main function, when it is
defined as int main(int argc, char *argv, char *envp).
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
calling process are cleared. Any signals set to be caught
by the calling process are reset to their default
If the current program is being ptraced, a SIGTRAP is sent
to it after a successful execve().
If the set-uid bit is set on the program file pointed to
by filename the effective user ID of the calling process
is changed to that of the owner of the program file. Sim
ilarly, when the set-gid bit of the program file is set
the effective group ID of the calling process is set to
the group of the program file.
If the executable is an a.out dynamically-linked binary
executable containing shared-library stubs, the Linux
dynamic linker ld.so(8) is called at the start of execu
tion to bring needed shared libraries into core and link
the executable with them.
If the executable is a dynamically-linked ELF executable,
the interpreter named in the PT_INTERP segment is used to
load the needed shared libraries. This interpreter is
linked with the GNU libc version 2.
On success, execve() does not return, on error -1 is
returned, and errno is set appropriately.
EACCES The file or a script interpreter is not a regular
EACCES Execute permission is denied for the file or a
script or ELF interpreter.
EACCES The file system is mounted noexec.
EPERM The file system is mounted nosuid, the user is not
the superuser, and the file has an SUID or SGID bit
EPERM The process is being traced, the user is not the
superuser and the file has an SUID or SGID bit set.
E2BIG The argument list is too big.
An executable is not in a recognised format, is for
the wrong architecture, or has some other format
error that means it cannot be executed.
EFAULT filename points outside your accessible address
filename is too long.
ENOENT The file filename or a script or ELF interpreter
does not exist.
ENOMEM Insufficient kernel memory was available.
A component of the path prefix of filename or a
script or ELF interpreter is not a directory.
EACCES Search permission is denied on a component of the
path prefix of filename or the name of a script
ELOOP Too many symbolic links were encountered in resolv
ing filename or the name of a script or ELF inter
Executable was open for writing by one or more pro
EIO An I/O error occurred.
ENFILE The limit on the total number of files open on the
system has been reached.
EMFILE The process has the maximum number of files open.
EINVAL An ELF executable had more than one PT_INTERP seg
ment (i.e., tried to name more than one inter
EISDIR An ELF interpreter was a directory.
An ELF interpreter was not in a recognised format.
SVr4, SVID, X/OPEN, BSD 4.3. POSIX does not document the
#! behavior but is otherwise compatible. SVr4 documents
additional error conditions EAGAIN, EINTR, ELIBACC, ENO
LINK, EMULTIHOP; POSIX does not document ETXTBSY, EPERM,
EFAULT, ELOOP, EIO, ENFILE, EMFILE, EINVAL, EISDIR or
ELIBBAD error conditions.
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.
Linux ignores the SUID and SGID bits on scripts.
chmod(2), fork(2), execl(3), environ(5), ld.so(8)