aa7c8cac11
Following is a list of functional changes: * The -o flag outputs the entire buffer to the length returned by the syscall, or, in case of fd2path(2) and errstr(2), to '\0'. * The -x flag is removed; the above makes it possible to pipe into xd(1) to get the same result. * The -s flag uses dirfmt(2) to format the stat message, instead of trying to imitate ls(1). * Stderr reports are normalized and made easier to parse. The code also suffered a number of stylistic changes.
83 lines
1.4 KiB
Plaintext
83 lines
1.4 KiB
Plaintext
.TH SYSCALL 1
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.SH NAME
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syscall \- test a system call
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.SH SYNOPSIS
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.B syscall
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[
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.B -os
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]
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.I entry
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[
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.I arg ...
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]
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.SH DESCRIPTION
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.I Syscall
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invokes the system call
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.I entry
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with the given arguments.
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The return value is printed.
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If an error occured, the error string is also printed.
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.PP
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For convenience,
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.IR write (2)
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and
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.IR read (2)
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are included in
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.IR entries ,
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even though they are not strictly syscalls.
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.PP
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.I Syscall
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arguments are integer constants, strings, or the literal
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.BR buf .
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The literal
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.B buf
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refers to a writable 1 megabyte buffer.
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Strings and
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.B buf
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are passed as pointers.
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Integers are passed as values.
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.PP
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The
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.B -o
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option prints contents of the 1MB buffer.
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For
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.IR errstr (2)
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and
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.IR fd2path (2),
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the buffer is treated as a 0-terminated string.
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For other calls, the number of bytes printed is
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determined by the system call's return value.
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.PP
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The
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.B -s
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option is similar, but interprets the data as a
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.IR stat (5)
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message and formats it to standard output.
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.SH EXAMPLES
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Write a string to standard output:
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.IP
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.EX
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syscall write 1 hello 5
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.EE
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.PP
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Print information about the file connected to standard input:
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.IP
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.EX
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syscall -s fstat 0 buf 1024
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.EE
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.SH SOURCE
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.B /sys/src/cmd/syscall
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.SH "SEE ALSO"
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Section 2 of this manual.
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.SH DIAGNOSTICS
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If
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.I entry
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is not known to
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.IR syscall ,
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the exit status is
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.LR unknown .
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If the system call succeeds, the exit status is null;
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otherwise the exit status is the string that
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.IR errstr (2)
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returns.
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