JavaScript: tail a local file
After reading this question I noticed - despite the initial question - the solution provided works only for remote files unless you have a webserver.
Instead I'm looking for a solution (that doesn't use Node.js) to "tail -f" a local file (on the same machine where the script runs) in order to read its changes. The script runs in a QML item, so no browsers nor webservers are involved.
The file might be updated quite quickly: i.e. several times per second, but with few chars at time only.
I'm able to read the file's content using an XMLHttpRequest but it seems it doesn't fit for my purpose.
UPDATE
After the downvote and the closing request I try to explain in other words.
I'm working on a commercial device that offers a loader for QML objects only. I cannot write C++ applications, there's no compilers, etc...
Into /tmp folder there's a file that is continuously updated by a bash script. In my QML object I need to parse each line as soon as it is appended. The Qt version is 4.x and QtQuick is 1.1.
So I'm asking a way to achieve this goal with these constraints.
javascript file qml tail
asked Nov 12 '18 at 8:11
MarkMark
1,07311433
|
show 3 more comments
After reading this question I noticed - despite the initial question - the solution provided works only for remote files unless you have a webserver.
Instead I'm looking for a solution (that doesn't use Node.js) to "tail -f" a local file (on the same machine where the script runs) in order to read its changes. The script runs in a QML item, so no browsers nor webservers are involved.
The file might be updated quite quickly: i.e. several times per second, but with few chars at time only.
I'm able to read the file's content using an XMLHttpRequest but it seems it doesn't fit for my purpose.
UPDATE
After the downvote and the closing request I try to explain in other words.
I'm working on a commercial device that offers a loader for QML objects only. I cannot write C++ applications, there's no compilers, etc...
Into /tmp folder there's a file that is continuously updated by a bash script. In my QML object I need to parse each line as soon as it is appended. The Qt version is 4.x and QtQuick is 1.1.
So I'm asking a way to achieve this goal with these constraints.
javascript file qml tail
asked Nov 12 '18 at 8:11
MarkMark
1,07311433
1
You said "a pure JavaScript way" but (a) XMLHttpRequest isn't "pure" JavaScript and (b) "pure" JavaScript has no input/output features at all, it depends entirely on the host environment to provide an API.
– Quentin
Nov 12 '18 at 8:13
It's written in the question: it's a QML object. Sorry for the misleading words, I will correct them. I mean without Node.js.
– Mark
Nov 12 '18 at 8:14
I know practically nothing of QML but a poke at the documentation says you should read the file from the main language for your app and then expose it to JS via a property binding and/or signal handler.
– Quentin
Nov 12 '18 at 8:18
@Quentin yes, that's the standard way and I'm doing it daily. This time I cannot use a backend C++ application. Hence I asked how to do this in JS only.
– Mark
Nov 12 '18 at 8:26
1
ECMAScript is the underlying language for JavaScript (typically written as "javascript" to mean implementations that support a DOM and i/o). Both require a host environment. ECMAScript has zero i/o, javascript has i/o depending on the implementation (e.g. various browsers, node, etc. see List of ECMAScript implementations).
– RobG
Nov 12 '18 at 8:36
|
show 3 more comments
After reading this question I noticed - despite the initial question - the solution provided works only for remote files unless you have a webserver.
Instead I'm looking for a solution (that doesn't use Node.js) to "tail -f" a local file (on the same machine where the script runs) in order to read its changes. The script runs in a QML item, so no browsers nor webservers are involved.
The file might be updated quite quickly: i.e. several times per second, but with few chars at time only.
I'm able to read the file's content using an XMLHttpRequest but it seems it doesn't fit for my purpose.
UPDATE
After the downvote and the closing request I try to explain in other words.
I'm working on a commercial device that offers a loader for QML objects only. I cannot write C++ applications, there's no compilers, etc...
Into /tmp folder there's a file that is continuously updated by a bash script. In my QML object I need to parse each line as soon as it is appended. The Qt version is 4.x and QtQuick is 1.1.
So I'm asking a way to achieve this goal with these constraints.
javascript file qml tail
asked Nov 12 '18 at 8:11
MarkMark
1,07311433
After reading this question I noticed - despite the initial question - the solution provided works only for remote files unless you have a webserver.
Instead I'm looking for a solution (that doesn't use Node.js) to "tail -f" a local file (on the same machine where the script runs) in order to read its changes. The script runs in a QML item, so no browsers nor webservers are involved.
The file might be updated quite quickly: i.e. several times per second, but with few chars at time only.
I'm able to read the file's content using an XMLHttpRequest but it seems it doesn't fit for my purpose.
UPDATE
After the downvote and the closing request I try to explain in other words.
I'm working on a commercial device that offers a loader for QML objects only. I cannot write C++ applications, there's no compilers, etc...
Into /tmp folder there's a file that is continuously updated by a bash script. In my QML object I need to parse each line as soon as it is appended. The Qt version is 4.x and QtQuick is 1.1.
So I'm asking a way to achieve this goal with these constraints.
javascript file qml tail
javascript file qml tail
asked Nov 12 '18 at 8:11
MarkMark
1,07311433
asked Nov 12 '18 at 8:11
MarkMark
1,07311433
edited Nov 12 '18 at 9:26
Mark
asked Nov 12 '18 at 8:11
MarkMark
1,07311433
asked Nov 12 '18 at 8:11
MarkMark
1,07311433
asked Nov 12 '18 at 8:11
MarkMark
1,07311433
1,07311433
1
You said "a pure JavaScript way" but (a) XMLHttpRequest isn't "pure" JavaScript and (b) "pure" JavaScript has no input/output features at all, it depends entirely on the host environment to provide an API.
– Quentin
Nov 12 '18 at 8:13
It's written in the question: it's a QML object. Sorry for the misleading words, I will correct them. I mean without Node.js.
– Mark
Nov 12 '18 at 8:14
I know practically nothing of QML but a poke at the documentation says you should read the file from the main language for your app and then expose it to JS via a property binding and/or signal handler.
– Quentin
Nov 12 '18 at 8:18
@Quentin yes, that's the standard way and I'm doing it daily. This time I cannot use a backend C++ application. Hence I asked how to do this in JS only.
– Mark
Nov 12 '18 at 8:26
1
ECMAScript is the underlying language for JavaScript (typically written as "javascript" to mean implementations that support a DOM and i/o). Both require a host environment. ECMAScript has zero i/o, javascript has i/o depending on the implementation (e.g. various browsers, node, etc. see List of ECMAScript implementations).
– RobG
Nov 12 '18 at 8:36
|
show 3 more comments
1
You said "a pure JavaScript way" but (a) XMLHttpRequest isn't "pure" JavaScript and (b) "pure" JavaScript has no input/output features at all, it depends entirely on the host environment to provide an API.
– Quentin
Nov 12 '18 at 8:13
It's written in the question: it's a QML object. Sorry for the misleading words, I will correct them. I mean without Node.js.
– Mark
Nov 12 '18 at 8:14
I know practically nothing of QML but a poke at the documentation says you should read the file from the main language for your app and then expose it to JS via a property binding and/or signal handler.
– Quentin
Nov 12 '18 at 8:18
@Quentin yes, that's the standard way and I'm doing it daily. This time I cannot use a backend C++ application. Hence I asked how to do this in JS only.
– Mark
Nov 12 '18 at 8:26
1
ECMAScript is the underlying language for JavaScript (typically written as "javascript" to mean implementations that support a DOM and i/o). Both require a host environment. ECMAScript has zero i/o, javascript has i/o depending on the implementation (e.g. various browsers, node, etc. see List of ECMAScript implementations).
– RobG
Nov 12 '18 at 8:36
1
1
You said "a pure JavaScript way" but (a) XMLHttpRequest isn't "pure" JavaScript and (b) "pure" JavaScript has no input/output features at all, it depends entirely on the host environment to provide an API.
– Quentin
Nov 12 '18 at 8:13
You said "a pure JavaScript way" but (a) XMLHttpRequest isn't "pure" JavaScript and (b) "pure" JavaScript has no input/output features at all, it depends entirely on the host environment to provide an API.
– Quentin
Nov 12 '18 at 8:13
It's written in the question: it's a QML object. Sorry for the misleading words, I will correct them. I mean without Node.js.
– Mark
Nov 12 '18 at 8:14
It's written in the question: it's a QML object. Sorry for the misleading words, I will correct them. I mean without Node.js.
– Mark
Nov 12 '18 at 8:14
I know practically nothing of QML but a poke at the documentation says you should read the file from the main language for your app and then expose it to JS via a property binding and/or signal handler.
– Quentin
Nov 12 '18 at 8:18
I know practically nothing of QML but a poke at the documentation says you should read the file from the main language for your app and then expose it to JS via a property binding and/or signal handler.
– Quentin
Nov 12 '18 at 8:18
@Quentin yes, that's the standard way and I'm doing it daily. This time I cannot use a backend C++ application. Hence I asked how to do this in JS only.
– Mark
Nov 12 '18 at 8:26
@Quentin yes, that's the standard way and I'm doing it daily. This time I cannot use a backend C++ application. Hence I asked how to do this in JS only.
– Mark
Nov 12 '18 at 8:26
1
1
ECMAScript is the underlying language for JavaScript (typically written as "javascript" to mean implementations that support a DOM and i/o). Both require a host environment. ECMAScript has zero i/o, javascript has i/o depending on the implementation (e.g. various browsers, node, etc. see List of ECMAScript implementations).
– RobG
Nov 12 '18 at 8:36
ECMAScript is the underlying language for JavaScript (typically written as "javascript" to mean implementations that support a DOM and i/o). Both require a host environment. ECMAScript has zero i/o, javascript has i/o depending on the implementation (e.g. various browsers, node, etc. see List of ECMAScript implementations).
– RobG
Nov 12 '18 at 8:36
|
show 3 more comments
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1
You said "a pure JavaScript way" but (a) XMLHttpRequest isn't "pure" JavaScript and (b) "pure" JavaScript has no input/output features at all, it depends entirely on the host environment to provide an API.
– Quentin
Nov 12 '18 at 8:13
It's written in the question: it's a QML object. Sorry for the misleading words, I will correct them. I mean without Node.js.
– Mark
Nov 12 '18 at 8:14
I know practically nothing of QML but a poke at the documentation says you should read the file from the main language for your app and then expose it to JS via a property binding and/or signal handler.
– Quentin
Nov 12 '18 at 8:18
@Quentin yes, that's the standard way and I'm doing it daily. This time I cannot use a backend C++ application. Hence I asked how to do this in JS only.
– Mark
Nov 12 '18 at 8:26
1
ECMAScript is the underlying language for JavaScript (typically written as "javascript" to mean implementations that support a DOM and i/o). Both require a host environment. ECMAScript has zero i/o, javascript has i/o depending on the implementation (e.g. various browsers, node, etc. see List of ECMAScript implementations).
– RobG
Nov 12 '18 at 8:36