Subversion Repositories planix.SVN

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 - 1 
.TH SYSCALL 1
2 
.SH NAME
3 
syscall \- test a system call
4 
.SH SYNOPSIS
5 
.B syscall
6 
[
7 
.B -osx
8 
]
9 
.I entry
10 
[
11 
.I arg ...
12 
]
13 
.SH DESCRIPTION
14 
.I Syscall
15 
invokes the system call
16 
.I entry
17 
with the given arguments.
18 
(Some functions, such as
19 
.I write
20 
and
21 
.IR read (2),
22 
although not strictly system calls, are valid
23 
.IR entries .)
24 
It prints the return value and the error string, if there was an error.
25 
An argument is either an integer constant as in C (its value is passed),
26 
a string (its address is passed),
27 
or the literal
28 
.B buf
29 
(a pointer to a 1MB buffer is passed).
30 
.PP
31 
If
32 
.B -o
33 
is given, the contents of the 1MB buffer are printed as a zero-terminated string
34 
after the system call is done.
35 
The
36 
.B -x
37 
and
38 
.B -s
39 
options are similar, but
40 
.B -x
41 
formats the data as hexadecimal bytes, while
42 
.B -s
43 
interprets the data as a
44 
.IR stat (5)
45 
message and formats it similar to the style of
46 
.B ls
47 
.B -lqm
48 
(see
49 
.IR ls (1)),
50 
with extra detail about the modify and access times.
51 
.SH EXAMPLES
52 
Write a string to standard output:
53 
.IP
54 
.EX
55 
syscall write 1 hello 5
56 
.EE
57 
.PP
58 
Print information about the file connected to standard input:
59 
.IP
60 
.EX
61 
syscall -s fstat 0 buf 1024
62 
.EE
63 
.SH SOURCE
64 
.B /sys/src/cmd/syscall
65 
.SH "SEE ALSO"
66 
Section 2 of this manual.
67 
.SH DIAGNOSTICS
68 
If
69 
.I entry
70 
is not known to
71 
.IR syscall ,
72 
the exit status is
73 
.LR unknown .
74 
If the system call succeeds, the exit status is null;
75 
otherwise the exit status is the string that
76 
.IR errstr (2)
77 
returns.