SYSCALL(1)SYSCALL(1)
NAME
syscall – test a system call
SYNOPSIS
syscall
[
-os
]
entry
[
arg ...
]
DESCRIPTION
Syscall
invokes the system call
entry
with the given arguments.
The return value is printed.
If an error occured, the error string is also printed.
For convenience,
write(2)
and
read(2)
are included in
entries,
even though they are not strictly syscalls.
Syscall
arguments are integer constants, strings, or the literal
buf.
The literal
buf
refers to a writable 1 megabyte buffer.
Strings and
buf
are passed as pointers.
Integers are passed as values.
The
-o
option prints contents of the 1MB buffer.
For
errstr(2)
and
fd2path(2),
the buffer is treated as a 0-terminated string.
For other calls, the number of bytes printed is
determined by the system call’s return value.
The
-s
option is similar, but interprets the data as a
stat(5)
message and formats it to standard output.
EXAMPLES
Write a string to standard output:
syscall write 1 hello 5
Print information about the file connected to standard input:
syscall -s fstat 0 buf 1024
SOURCE
/sys/src/cmd/syscall
SEE ALSO
Section 2 of this manual.
DIAGNOSTICS
If
entry
is not known to
syscall,
the exit status is
unknown.
If the system call succeeds, the exit status is null;
otherwise the exit status is the string that
errstr(2)
returns.