os - os Operation

Adapted Air780E

Note

This page document is automatically generated by this file. If there is any error, please submit issue or help modify pr, thank you！

Tip

This library has its own demo,click this link to view demo examples of OS

Example

-- os The module is a lua native module. This document is intended to facilitate the exposition of common problems in actual use.

-- Please refer to the native documentation https://wiki.luatos.org/_static/lua53doc/manual.html#6.9

os.remove(path)

Remove File

Parameters

Incoming Value Type	Explanation
string	Full path of the file to be removed

Return Value

return value type	explanation
bool	Returns true for success, otherwise nil
string	Return reason string on failure

Examples

-- Delete a file in the root directory
os.remove("/1.txt")
-- Note that the files during line brushing are usually in the/luadb directory, and the files in this directory are read-only.
-- That is, it cannot be executed. os.remove("/luadb/xxx.bin")

---

os.rename(old_path, new_path)

File Rename

Parameters

Incoming Value Type	Explanation
string	Full path of source file
string	target file full path

Return Value

return value type	explanation
bool	Returns true for success, otherwise nil
string	Return reason string on failure

Examples

-- Note that only files under the same file system can be renamed
-- For example:
os.rename("/1.txt", "/2.txt")
-- different file system, or the source file system is read-only,
--os.rename("/luadb/1.txt", "/luadb/2.txt")
--os.rename("/luadb/1.txt", "/2.txt")

---

os.clock()

Returns an approximation of the CPU time in seconds used by the program

Parameters

Incoming Value Type	Explanation
return	Timestamp

Return Value

None

Examples

-- Not recommend the use of this API
-- To get a timestamp, use os.time()
-- To obtain the system runtime, use mcu.ticks()

---

os.date(fmt, time)

Date Function

Parameters

Incoming Value Type	Explanation
string	A formatted string, which can be nil
table	date-time table

Return Value

return value type	explanation
table/string	Depending on the fmt, the return value is different

Examples

-- A few points worth noting:
-- 1. If UTC time is required, the first character of fmt is written"!"
-- 2. fmt The formatting of follows the C function strftime, which can be consulted. https://developer.aliyun.com/article/320480

-- Get local time string
log.info("Local time string", os.date())
-- Get UTC time string
log.info("UTC Time String", os.date("!%c"))
-- Format local time string
log.info("Local time string", os.date("%Y-%m-%d %H:%M:%S"))
-- Formatting a UTC Time String
log.info("UTC Time String", os.date("!%Y-%m-%d %H:%M:%S"))
-- Format Time String
log.info("Custom time string", os.date("!%Y-%m-%d %H:%M:%S", os.time({year=2000, mon=1, day=1, hour=0, min=0, sec=0})))

-- Gets the local time of table
log.info("Local time string", json.encode(os.date("*t")))
-- Gets the UTC time table
log.info("UTC Time String",  json.encode(os.date("!*t")))

---

os.time(mytime)

timestamp function

Parameters

Incoming Value Type	Explanation
table	date-time table
return	Timestamp

Return Value

None

Examples

-- Note that this function returns a UTC timestamp
-- timestamp, but the accuracy under lua can only reach seconds
log.info("UTC Timestamp", os.time())
log.info("Custom Timestamp", os.time({year=2000, mon=1, day=1, hour=0, min=0, sec=0}))

---

os.difftime(timeA, timeB)

time difference

Parameters

Incoming Value Type	Explanation
int	Time A, numeric type
int	Time B, numeric type

Return Value

return value type	explanation
int	time difference

Examples

None

---