.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft int
-.Fn execve "const char *path" "char *const argv[]" "char *const envp[]"
+.Fo execve
+.Fa "const char *path"
+.Fa "char *const argv[]"
+.Fa "char *const envp[]"
+.Fc
.Sh DESCRIPTION
.Fn Execve
transforms the calling process into a new process.
.Bd -filled -offset indent -compact
.Sy \&#!
.Em interpreter
-.Bq Em arg
+.Bq Em arg ...
.Ed
.Pp
When an interpreter file is
.Fn execve Ap d ,
-the system
-.Fn execve Ap s
-runs the specified
+the system runs the specified
.Em interpreter .
-If the optional
-.Em arg
-is specified, it becomes the first argument to the
-.Em interpreter ,
-and the name of the originally
+If any optional
+.Em args
+are specified, they become the first (second, ...) argument to the
+.Em interpreter.
+The name of the originally
.Fn execve Ap d
-file becomes the second argument;
+file becomes the subsequent argument;
otherwise, the name of the originally
.Fn execve Ap d
-file becomes the first argument. The original arguments are shifted over to
-become the subsequent arguments. The zeroth argument, normally the name of the
+file is the first argument.
+The original arguments to the invocation of the interpreter
+are shifted over to become the final arguments.
+The zeroth argument, normally the name of the
.Fn execve Ap d
file, is left unchanged.
.Pp
.Sh RETURN VALUES
As the
.Fn execve
-function overlays the current process image
-with a new process image the successful call
-has no process to return to.
+function overlays the current process image with a new process image,
+the successful call has no process to return to.
If
.Fn execve
-does return to the calling process an error has occurred; the
-return value will be -1 and the global variable
+does return to the calling process, an error has occurred;
+the return value will be -1 and the global variable
.Va errno
is set to indicate the error.
.Sh ERRORS
.Fn Execve
will fail and return to the calling process if:
.Bl -tag -width Er
-.It Bq Er ENOTDIR
-A component of the path prefix is not a directory.
-.It Bq Er ENAMETOOLONG
-A component of a pathname exceeded
-.Dv {NAME_MAX}
-characters, or an entire path name exceeded
-.Dv {PATH_MAX}
-characters.
-.It Bq Er ENOENT
-The new process file does not exist.
-.It Bq Er ELOOP
-Too many symbolic links were encountered in translating the pathname.
+.\" ==========
+.It Bq Er E2BIG
+The number of bytes in the new process's argument list
+is larger than the system-imposed limit.
+This limit is specified by the
+.Xr sysctl 3
+MIB variable
+.Dv KERN_ARGMAX .
+.\" ==========
.It Bq Er EACCES
Search permission is denied for a component of the path prefix.
+.\" ==========
.It Bq Er EACCES
The new process file is not an ordinary file.
+.\" ==========
.It Bq Er EACCES
The new process file mode denies execute permission.
+.\" ==========
.It Bq Er EACCES
-The new process file is on a filesystem mounted with execution
-disabled
+The new process file is on a filesystem mounted
+with execution disabled
.Pf ( Dv MNT_NOEXEC
in
.Ao Pa sys/mount.h Ac ) .
-.It Bq Er ENOEXEC
-The new process file has the appropriate access
-permission, but has an invalid magic number in its header.
-.It Bq Er ETXTBSY
-The new process file is a pure procedure (shared text)
-file that is currently open for writing or reading by some process.
-.It Bq Er ENOMEM
-The new process requires more virtual memory than
-is allowed by the imposed maximum
-.Pq Xr getrlimit 2 .
-.It Bq Er E2BIG
-The number of bytes in the new process's argument list
-is larger than the system-imposed limit.
-The limit in the system as released is 20480 bytes
-.Pf ( Dv NCARGS
-in
-.Ao Pa sys/param.h Ac ) .
+.\" ==========
.It Bq Er EFAULT
The new process file is not as long as indicated by
the size values in its header.
+.\" ==========
.It Bq Er EFAULT
.Fa Path ,
.Fa argv ,
.Fa envp
point
to an illegal address.
+.\" ==========
.It Bq Er EIO
An I/O error occurred while reading from the file system.
+.\" ==========
+.It Bq Er ELOOP
+Too many symbolic links were encountered in translating the pathname.
+This is taken to be indicative of a looping symbolic link.
+.\" ==========
+.It Bq Er ENAMETOOLONG
+A component of a pathname exceeded
+.Dv {NAME_MAX}
+characters, or an entire path name exceeded
+.Dv {PATH_MAX}
+characters.
+.\" ==========
+.It Bq Er ENOENT
+The new process file does not exist.
+.\" ==========
+.It Bq Er ENOEXEC
+The new process file has the appropriate access
+permission, but has an unrecognized format
+(e.g., an invalid magic number in its header).
+.\" ==========
+.It Bq Er ENOMEM
+The new process requires more virtual memory than
+is allowed by the imposed maximum
+.Pq Xr getrlimit 2 .
+.\" ==========
+.It Bq Er ENOTDIR
+A component of the path prefix is not a directory.
+.\" ==========
+.It Bq Er ETXTBSY
+The new process file is a pure procedure (shared text)
+file that is currently open for writing or reading by some process.
.El
.Sh CAVEAT
If a program is
.Xr exit 2 ,
.Xr fork 2 ,
.Xr execl 3 ,
+.Xr sysctl 3 ,
.Xr environ 7
.Sh HISTORY
The
projects / apple / xnu.git / blobdiff