OCAMLRUN(1)OCAMLRUN(1)NAMEocamlrun - The OCaml bytecode interpreter
SYNOPSISocamlrun [ options ] filename argument ...
DESCRIPTION
The ocamlrun(1) command executes bytecode files produced by the linking
phase of the ocamlc(1) command.
The first non-option argument is taken to be the name of the file con‐
taining the executable bytecode. (That file is searched in the exe‐
cutable path as well as in the current directory.) The remaining argu‐
ments are passed to the OCaml program, in the string array Sys.argv.
Element 0 of this array is the name of the bytecode executable file;
elements 1 to n are the remaining arguments.
In most cases, the bytecode executable files produced by the ocamlc(1)
command are self-executable, and manage to launch the ocamlrun(1) com‐
mand on themselves automatically.
OPTIONS
The following command-line options are recognized by ocamlrun(1).
-b When the program aborts due to an uncaught exception, print a
detailed "back trace" of the execution, showing where the excep‐
tion was raised and which function calls were outstanding at
this point. The back trace is printed only if the bytecode exe‐
cutable contains debugging information, i.e. was compiled and
linked with the -g option to ocamlc(1) set. This option is
equivalent to setting the b flag in the OCAMLRUNPARAM environ‐
ment variable (see below).
-I dir Search the directory dir for dynamically-loaded libraries, in
addition to the standard search path.
-p Print the names of the primitives known to this version of
ocamlrun(1) and exit.
-v Direct the memory manager to print verbose messages on standard
error. This is equivalent to setting v=63 in the OCAMLRUNPARAM
environment variable (see below).
-version
Print version string and exit.
-vnum Print short version number and exit.
ENVIRONMENT VARIABLES
The following environment variable are also consulted:
CAML_LD_LIBRARY_PATH
Additional directories to search for dynamically-loaded
libraries.
OCAMLLIB
The directory containing the OCaml standard library. (If OCAML‐
LIB is not set, CAMLLIB will be used instead.) Used to locate
the ld.conf configuration file for dynamic loading. If not set,
default to the library directory specified when compiling OCaml.
OCAMLRUNPARAM
Set the runtime system options and garbage collection parame‐
ters. (If OCAMLRUNPARAM is not set, CAMLRUNPARAM will be used
instead.) This variable must be a sequence of parameter speci‐
fications. A parameter specification is an option letter fol‐
lowed by an = sign, a decimal number (or a hexadecimal number
prefixed by 0x), and an optional multiplier. The options are
documented below; the last six correspond to the fields of the
control record documented in The OCaml user's manual, chapter
"Standard Library", section "Gc".
b Trigger the printing of a stack backtrace when an uncaught
exception aborts the program. This option takes no argument.
p Turn on debugging support for ocamlyacc-generated parsers. When
this option is on, the pushdown automaton that executes the
parsers prints a trace of its actions. This option takes no
argument.
R Turn on randomization of all hash tables by default (see the
Hashtbl module of the standard library). This option takes no
argument.
h The initial size of the major heap (in words).
a (allocation_policy)
The policy used for allocating in the OCaml heap. Possible val‐
ues are 0 for the next-fit policy, and 1 for the first-fit pol‐
icy. Next-fit is usually faster, but first-fit is better for
avoiding fragmentation and the associated heap compactions.
s (minor_heap_size)
The size of the minor heap (in words).
i (major_heap_increment)
The default size increment for the major heap (in words).
o (space_overhead)
The major GC speed setting.
O (max_overhead)
The heap compaction trigger setting.
l (stack_limit)
The limit (in words) of the stack size.
v (verbose)
What GC messages to print to stderr. This is a sum of values
selected from the following:
0x001 Start of major GC cycle.
0x002 Minor collection and major GC slice.
0x004 Growing and shrinking of the heap.
0x008 Resizing of stacks and memory manager tables.
0x010 Heap compaction.
0x020 Change of GC parameters.
0x040 Computation of major GC slice size.
0x080 Calling of finalisation functions.
0x100 Startup messages (loading the bytecode executable file,
resolving shared libraries).
The multiplier is k, M, or G, for multiplication by 2^10, 2^20,
and 2^30 respectively. For example, on a 32-bit machine under
bash, the command export OCAMLRUNPARAM='s=256k,v=1' tells a sub‐
sequent ocamlrun to set its initial minor heap size to 1
megabyte and to print a message at the start of each major GC
cycle.
CAMLRUNPARAM
If OCAMLRUNPARAM is not found in the environment, then CAMLRUN‐
PARAM will be used instead. If CAMLRUNPARAM is not found, then
the default values will be used.
PATH List of directories searched to find the bytecode executable
file.
SEE ALSOocamlc(1).
The OCaml user's manual, chapter "Runtime system".
OCAMLRUN(1)
