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35864: add sysopen, sysseek and systell to system module

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This commit is contained in:
Oliver Kiddle 2015-07-24 12:36:35 +02:00
parent acf1fa6034
commit 0f02b27ab0
4 changed files with 246 additions and 2 deletions
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58
Doc/Zsh/mod_system.yo
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@ -28,6 +28,47 @@ system's range), a return status of 1 indicates an error in the
parameters, and a return status of 2 indicates the error name was
not recognised (no message is printed for this).
)
findex(sysopen)
redef(SPACES)(0)(tt(ifztexi(NOTRANS(@ @ @ @ @ @ @ @ ))ifnztexi( )))
xitem(tt(sysopen) [ tt(-arw) ] [ tt(-m) var(permissions) ] [ tt(-o) var(options) ])
item(SPACES()[ tt(-u) var(fd) ] var(file))(
This command opens a file. The tt(-r), tt(-w) and tt(-a) flags indicate
whether the file should be opened for reading, writing and appending,
respectively. The tt(-m) option allows the initial permissions to use when
creating a file to be specified in octal form. The file descriptor is
specified with -u. Either an explicit file descriptor in the range 0 to 9 can
be specified or a variable name can be given to which the file descriptor
number will be assigned.
The tt(-o) option allows various system specific options to be
specified as a comma-separated list. The following is a list of possible
options. Note that, depending on the system, some may not be available.
startitem()
item(tt(cloexec))(
mark file to be closed when other programs are executed
)
xitem(tt(create))
item(tt(creat))(
create file if it does not exist
)
item(tt(excl))(
create file, error if it already exists
)
item(tt(noatime))(
suppress updating of the file atime
)
item(tt(nofollow))(
fail if var(file) is a symbolic link
)
item(tt(sync))(
request that writes wait until data has been physically written
)
xitem(tt(truncate))
item(tt(trunc))(
truncate file to size 0
)
enditem()
)
findex(sysread)
redef(SPACES)(0)(tt(ifztexi(NOTRANS(@ @ @ @ @ @ @ @ ))ifnztexi( )))
xitem(tt(sysread )[ tt(-c) var(countvar) ] [ tt(-i) var(infd) ] [ tt(-o) var(outfd) ])
@ -89,6 +130,14 @@ usual rules; no write to var(outfd) is attempted.
)
enditem()
)
item(tt(sysseek) [ tt(-u) var(fd) ] [ tt(-w) tt(start)|tt(end)|tt(current) ] var(offset))(
The current file position at which future reads and writes will take place is
adjusted to the specified byte offset. The var(offset) is evaluated as a math
expression. The tt(-u) option allows the file descriptor to be specified. By
default the offset is specified relative to the start or the file but, with the
tt(-w) option, it is possible to specify that the offset should be relative to
the current position or the end of the file.
)
item(tt(syswrite) [ tt(-c) var(countvar) ] [ tt(-o) var(outfd) ] var(data))(
The data (a single string of bytes) are written to the file descriptor
var(outfd), or 1 if that is not given, using the tt(write) system call.
@ -161,6 +210,15 @@ version of the shell before it was implemented).
)
enditem()
subsect(Math Functions)
startitem()
item(tt(systell+LPAR()var(fd)RPAR()))(
The systell math function returns the current file position for the file
descriptor passed as an argument.
)
enditem()
subsect(Parameters)
startitem()