6. 文件输入输出库

FIO 模块向 Daslang 公开 C++ FILE * API、文件映射、目录和文件统计信息作例程。

所有函数和交易品种都在 “fio” 模块中，使用 require 来访问它。

require fio

6.1. Type aliases

file = FILE const?

alias for the FILE const?; its there since most file functions expect exactly this type

6.2. 常量

seek_set = 0

constant for fseek which sets the file pointer to the beginning of the file plus the offset.

seek_cur = 1

constant for fseek which sets the file pointer to the current position of the file plus the offset.

seek_end = 2

constant for fseek which sets the file pointer to the end of the file plus the offset.

df_magic = 0x12345678

obsolete. magic number for binary_save and binary_load.

df_header

df_header fields are

magic

uint

size

int

obsolete. header for the fsave and fload which internally use binary_save and binary_load.

6.3. 处理结构

FStat

FStat 字段是

is_valid

bool

FStat 属性运算符是

size

uint64

atime

builtin::clock

ctime

builtin::clock

mtime

builtin::clock

is_reg

bool

is_dir

bool

stat and fstat return file information in this structure.

6.4. 处理类型

FILE

Holds system specific FILE type.

6.5. 文件操作

remove(name: string const implicit)

remove returns bool

argument

argument type

name

string const implicit

deletes file specified by name

rename(old_name: string const implicit; new_name: string const implicit)

rename returns bool

argument

argument type

old_name

string const implicit

new_name

string const implicit

renames file.

fopen(name: string const implicit; mode: string const implicit)

fopen returns fio::FILE const? const

argument

argument type

name

string const implicit

mode

string const implicit

equivalent to C fopen. Opens file in different modes.

fclose(file: FILE const? const implicit)

argument

argument type

file

fio::FILE const? const implicit

equivalent to C fclose. Closes file.

fflush(file: FILE const? const implicit)

argument

argument type

file

fio::FILE const? const implicit

equivalent to C fflush. Flushes FILE buffers.

fprint(file: FILE const? const implicit; text: string const implicit)

argument

argument type

file

fio::FILE const? const implicit

text

string const implicit

same as print but outputs to file.

fread(file: FILE const? const implicit)

fread returns string

argument

argument type

file

fio::FILE const? const implicit

reads data from file.

fmap(file: FILE const? const implicit; block: block<(var arg0:array<uint8>#):void> const implicit)

argument

argument type

file

fio::FILE const? const implicit

block

block<(array<uint8>#):void> const implicit

create map view of file, i.e. maps file contents to memory. Data is available as array<uint8> inside the block.

fgets(file: FILE const? const implicit)

fgets returns string

argument

argument type

file

fio::FILE const? const implicit

equivalent to C fgets. Reads and returns new string from the line.

fwrite(file: FILE const? const implicit; text: string const implicit)

argument

argument type

file

fio::FILE const? const implicit

text

string const implicit

writes data fo file.

feof(file: FILE const? const implicit)

feof returns bool

argument

argument type

file

fio::FILE const? const implicit

equivalent to C feof. Returns true if end of file has been reached.

fseek(file: FILE const? const implicit; offset: int64 const; mode: int const)

fseek returns int64

argument

argument type

file

fio::FILE const? const implicit

offset

int64 const

mode

int const

equivalent to C fseek. Rewinds position of the current FILE pointer.

ftell(file: FILE const? const implicit)

ftell returns int64

argument

argument type

file

fio::FILE const? const implicit

equivalent to C ftell. Returns current FILE pointer position.

fstat(file: FILE const? const implicit; stat: FStat implicit)

fstat returns bool

argument

argument type

file

fio::FILE const? const implicit

stat

fio::FStat implicit

equivalent to C fstat. Returns information about file, such as file size, timestamp, etc.

stat(file: string const implicit; stat: FStat implicit)

stat returns bool

argument

argument type

file

string const implicit

stat

fio::FStat implicit

same as fstat, but file is specified by file name.

fstdin()

fstdin returns fio::FILE const? const

returns FILE pointer to standard input.

fstdout()

fstdout returns fio::FILE const? const

returns FILE pointer to standard output.

fstderr()

fstderr returns fio::FILE const? const

returns FILE pointer to standard error.

getchar()

getchar returns int

equivalent to C getchar. Reads and returns next character from standard input.

fload(file: file; size: int const; blk: block<(data:array<uint8> const):void> const)

argument

argument type

file

file

size

int const

blk

block<(data:array<uint8> const):void> const

obsolete. saves data to file.

fopen(name: string const; mode: string const; blk: block<(f:FILE const? const):void> const)

fopen returns auto

argument

argument type

name

string const

mode

string const

blk

block<(f: file ):void> const

equivalent to C fopen. Opens file in different modes.

stat(path: string const)

stat returns fio::FStat

argument

argument type

path

string const

same as fstat, but file is specified by file name.

fstat(f: file)

fstat returns fio::FStat

argument

argument type

f

file

equivalent to C fstat. Returns information about file, such as file size, timestamp, etc.

fread(f: file; blk: block<(data:string const#):auto> const)

fread returns auto

argument

argument type

f

file

blk

block<(data:string const#):auto> const

reads data from file.

fload(f: file; buf: auto(BufType) const)

fload returns auto

argument

argument type

f

file

buf

auto(BufType) const

obsolete. saves data to file.

fsave(f: file; buf: auto(BufType) const)

fsave returns auto

argument

argument type

f

file

buf

auto(BufType) const

obsolete. loads data from file.

fread(f: file; buf: auto(BufType) const implicit)

fread returns auto

argument

argument type

f

file

buf

auto(BufType) const implicit

reads data from file.

fread(f: file; buf: array<auto(BufType)> const implicit)

fread returns auto

argument

argument type

f

file

buf

array<auto(BufType)> const implicit

reads data from file.

fwrite(f: file; buf: auto(BufType) const implicit)

fwrite returns auto

argument

argument type

f

file

buf

auto(BufType) const implicit

writes data fo file.

fwrite(f: file; buf: array<auto(BufType)> const implicit)

fwrite returns auto

argument

argument type

f

file

buf

array<auto(BufType)> const implicit

writes data fo file.

6.6. Path manipulation

dir_name(name: string const implicit)

dir_name returns string

argument

argument type

name

string const implicit

equivalent to linux dirname. Splits path and returns the component preceding the final ‘/’. Trailing ‘/’ characters are not counted as part of the pathname.

base_name(name: string const implicit)

base_name returns string

argument

argument type

name

string const implicit

equivalent to linux basename. Splits path and returns the string up to, but not including, the final ‘/’.

get_full_file_name(path: string const implicit)

get_full_file_name returns string

argument

argument type

path

string const implicit

returns full name of the file in normalized form.

6.7. Directory manipulation

mkdir(path: string const implicit)

mkdir returns bool

argument

argument type

path

string const implicit

makes directory.

chdir(path: string const implicit)

chdir returns bool

argument

argument type

path

string const implicit

changes current directory.

getcwd()

getcwd returns string

returns current working directory.

dir(path: string const; blk: block<(filename:string const):void> const)

dir returns auto

argument

argument type

path

string const

blk

block<(filename:string const):void> const

iterates through all files in the specified path.

6.8. 特定于 OS 的例程

sleep(msec: uint const)

argument

argument type

msec

uint const

sleeps for specified number of milliseconds.

exit(exitCode: int const)

Warning

This is unsafe operation.

argument

argument type

exitCode

int const

equivalent to C exit. Terminates program.

popen(command: string const implicit; scope: block<(arg0:FILE const? const):void> const implicit)

popen returns int

Warning

This is unsafe operation.

argument

argument type

command

string const implicit

scope

block<( fio::FILE const? const):void> const implicit

equivalent to linux popen. Opens pipe to command.

popen_binary(command: string const implicit; scope: block<(arg0:FILE const? const):void> const implicit)

popen_binary returns int

Warning

This is unsafe operation.

argument

argument type

command

string const implicit

scope

block<( fio::FILE const? const):void> const implicit

opens pipe to command and returns FILE pointer to it, in binary mode.

get_env_variable(var: string const implicit)

get_env_variable returns string

argument

argument type

var

string const implicit

returns value of the environment variable.

sanitize_command_line(var: string const implicit)

sanitize_command_line returns string

argument

argument type

var

string const implicit

sanitizes command line arguments.