Is There a Way, an Extension Perhaps, that Enables to Seek and Read?

[Petr_Veprek]

I would like to tail a text file. With the standard File component, I can only read the entire file.

Is there some clever way, an extension, anything... to enable seek-and-read (i.e. tail)?

I have searched and looked at many extensions but did not find any solution.

[Peter]

With this extension you can use the tail command as you would like.

Using LINUX commands in App Inventor. Extension

Hello friends, with this extension we are going to use some LINUX commands. com.KIO4_Terminal.aix With this block we can copy files from the assets to SdCard. This block only works with the compiled app (Build). It needs AskForPermission = WRITE_EXTERNAL_STORAGE [extension_terminal3] [shell_permiss] oooooooooooooooOOOOOOOOOOOOOoooooooooooooo With this block we can copy files from the assets to the internal cache directory of the same application. We will get the address of the accessi…

[Anke]

@Petr_Veprek

I would like to tail a text file. With the standard File component, I can only read the entire file.

Please explain this in more detail, give an example.

[Petr_Veprek]

Brilliant! (the extension)

Not quite there though. (my need)

I can run "echo aha" --> "aha"
"uname" --> "Linux"
"ps" --> "... info about one process ..."
"tail --version" --> "toybox 0.8.0-android"
"tail --help" --> "... -n ... -c ... -f ..."
"ls" --> "" // EMPTY
"ls /" --> "" // EMPTY
"ls /system/" --> "... whole bunch of directories including bin ..."
"ls /system/bin/" --> "" // EMPTY
(I figure I am getting no output (EMPTY) in some cases due to permissions/file ownership.)

I would really like to run "tail -f ..." but there are no events to get the output as it is appended to the file. No worries, I think I can use "tail -n ..." to get the last few lines, compare the result to previous result and see what changed. If I can do this fast enought, it should work, So this is my current working plan... but I am running into trouble specifying the correct file path. My file is located in AppInventor/Data, let's call in tailme.txt

I need to run "tail -n 4 [some path]/tailme.txt" but I can't figure out the path to AppInventor/data location. Any idea?

[TIMAI2]

This conversation is also happening here:

File - Can't Access Files Outside AppInventor/data folder

I can read a file from AppInventor/data folder (in Internal storage). I can't read a file from another location. If the fileName does not start with a slash, it will be written in the program’s private data directory... Since writing can be done only to a specific directory, I assume the same applies to reading and so not being able to read from other file system locations is expected. Is this correct?

so closing this topic