Read from a file
Verified
Added by iNTERFACEWARE
How to open and read a file from disk, either one line at a time, or read the whole file at once
Source Code
-- How to read a whole file -- get a file handle local f = io.open('test') -- read the whole file f:read('*a') -- close the file handle f:close() -- How to read one line from a file -- get a file handle local f = io.open('test') -- read one line from the file f:read('*l') -- read another line from the file -- default is to read a one line f:read() -- close the file handle f:close()
Description
How to open and read a file from disk, either one line at a time, or read the whole file at once
Usage Details
There are three steps to read a file: Open the file, use the returned file handle to read the file, then close the file. You can either read the whole file contents, or just one line at a time.
How to use the snippet:
- Paste the code for the desired file reading method into your script
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Use iguana.isTest() to prevent code from running in the editor
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Use iguana.isTest() to allow code to run in the editor but not in the live channel
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Get the name or guid for the current channel by using iguana.channelName() or iguana.channelGuid()
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Use iguana.channelConfig{} to get configuration information for a channel, you can use either guid or channel name to specify the channel
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Get the Iguana log (unique) message ID for the message currently being processed
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Use iguana.setChannelStatus{} to set the channel dashboard channel status "light" and message
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Set the timeout for the current script, must be set inside a function, usually main().
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Use iguana.status() to return an XML summary of the local Iguana's runtime state
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Use iguana.stopOnError(false) to prevent a channel from stopping when an error occurs
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Use iguana.version() to get the Iguana version number, can be useful for testing for a required/supported version
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Use iguana.webInfo() to get web server and HTTP channel server configuration
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Use iguana.workingDir() to get the current Iguana working directory, where config files etc. are stored
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How to open a file and write (replace file content), or append data (keep file content)
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Use os.fs.access() to check if a file exists, and to verify the permissions
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Use os.fs.chmod() to set file permissions, using octal mode (symbolic mode does not work)
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Use os.remove() to delete a file or directory, only an empty directory can be deleted
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Use os.fs.rmdir() to delete an empty directory, if the directory is not empty an error is returned
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Use os.fs.rename() to rename a file or directory, if the file or directory does not exist an error is returned
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Use os.fs.stat() to get statistics for a file or directory