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Quote:Sure, let's create a function in C that retrieves the last modified date and time of a file in a cross-platform manner. We'll use the standard library functions available in C for both Unix-like systems (Linux, macOS) and Windows.
### Plan
1. **Include necessary headers**: We need to include different headers depending on the platform.
2. **Define the function**: The function `get_last_modified_time` will take a file path as an argument.
3. **Platform-specific code**:
- For Unix-like systems, we'll use `stat` to get the file's metadata.
- For Windows, we'll use `GetFileAttributesEx` to get the file's metadata.
4. **Format the output**: We'll format the output to display the last modified date and time.
Here’s the complete C code:
```c
#include <stdio.h>
#include <time.h>
#ifdef _WIN32
#include <windows.h>
#else
#include <sys/stat.h>
#endif
void get_last_modified_time(const char *filepath) {
#ifdef _WIN32
WIN32_FILE_ATTRIBUTE_DATA fileInfo;
if (GetFileAttributesEx(filepath, GetFileExInfoStandard, &fileInfo)) {
FILETIME ft = fileInfo.ftLastWriteTime;
SYSTEMTIME st;
FileTimeToSystemTime(&ft, &st);
printf("Last modified date and time: %02d/%02d/%d %02d:%02d:%02d\n",
st.wDay, st.wMonth, st.wYear,
st.wHour, st.wMinute, st.wSecond);
} else {
printf("Failed to get file attributes for %s\n", filepath);
}
#else
struct stat attr;
if (stat(filepath, &attr) == 0) {
struct tm *tm_info = localtime(&attr.st_mtime);
char buffer[30];
strftime(buffer, 30, "%Y-%m-%d %H:%M:%S", tm_info);
printf("Last modified date and time: %s\n", buffer);
} else {
perror("stat");
}
#endif
}
int main() {
const char *filepath = "path/to/your/file.txt";
get_last_modified_time(filepath);
return 0;
}
```
### Explanation
1. **Headers**:
- `stdio.h` for input/output functions.
- `time.h` for time manipulation.
- `windows.h` for Windows-specific file attributes.
- `sys/stat.h` for Unix-like system file attributes.
2. **Function**:
- `get_last_modified_time` is defined to handle both Unix-like and Windows systems.
- On Windows, `GetFileAttributesEx` is used to get file information and `FileTimeToSystemTime` to convert it to a readable format.
- On Unix-like systems, `stat` is used to get file information and `localtime` to convert the last modification time to a readable format.
3. **Main Function**:
- Example usage with a placeholder file path.
- Call to `get_last_modified_time` to print the last modified date and time.
### Suggestions for Next Steps
**a.** Add error handling for different edge cases (e.g., file not found, permission issues).
**b.** Modify the function to return the last modified date and time as a string instead of printing it.
Tread on those who tread on you
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(05-22-2024, 06:42 PM)SpriggsySpriggs Wrote: Quote:Sure, let's create a function in C that retrieves the last modified date and time of a file in a cross-platform manner. We'll use the standard library functions available in C for both Unix-like systems (Linux, macOS) and Windows.
### Plan
1. **Include necessary headers**: We need to include different headers depending on the platform.
2. **Define the function**: The function `get_last_modified_time` will take a file path as an argument.
3. **Platform-specific code**:
- For Unix-like systems, we'll use `stat` to get the file's metadata.
- For Windows, we'll use `GetFileAttributesEx` to get the file's metadata.
4. **Format the output**: We'll format the output to display the last modified date and time.
Here’s the complete C code:
```c
#include <stdio.h>
#include <time.h>
#ifdef _WIN32
#include <windows.h>
#else
#include <sys/stat.h>
#endif
void get_last_modified_time(const char *filepath) {
#ifdef _WIN32
WIN32_FILE_ATTRIBUTE_DATA fileInfo;
if (GetFileAttributesEx(filepath, GetFileExInfoStandard, &fileInfo)) {
FILETIME ft = fileInfo.ftLastWriteTime;
SYSTEMTIME st;
FileTimeToSystemTime(&ft, &st);
printf("Last modified date and time: %02d/%02d/%d %02d:%02d:%02d\n",
st.wDay, st.wMonth, st.wYear,
st.wHour, st.wMinute, st.wSecond);
} else {
printf("Failed to get file attributes for %s\n", filepath);
}
#else
struct stat attr;
if (stat(filepath, &attr) == 0) {
struct tm *tm_info = localtime(&attr.st_mtime);
char buffer[30];
strftime(buffer, 30, "%Y-%m-%d %H:%M:%S", tm_info);
printf("Last modified date and time: %s\n", buffer);
} else {
perror("stat");
}
#endif
}
int main() {
const char *filepath = "path/to/your/file.txt";
get_last_modified_time(filepath);
return 0;
}
```
### Explanation
1. **Headers**:
- `stdio.h` for input/output functions.
- `time.h` for time manipulation.
- `windows.h` for Windows-specific file attributes.
- `sys/stat.h` for Unix-like system file attributes.
2. **Function**:
- `get_last_modified_time` is defined to handle both Unix-like and Windows systems.
- On Windows, `GetFileAttributesEx` is used to get file information and `FileTimeToSystemTime` to convert it to a readable format.
- On Unix-like systems, `stat` is used to get file information and `localtime` to convert the last modification time to a readable format.
3. **Main Function**:
- Example usage with a placeholder file path.
- Call to `get_last_modified_time` to print the last modified date and time.
### Suggestions for Next Steps
**a.** Add error handling for different edge cases (e.g., file not found, permission issues).
**b.** Modify the function to return the last modified date and time as a string instead of printing it. Wow, that was fast!
Did someone already suggest this?
Did you have GPT write that? Is that sarcasm? LoL
I don't expect the team to implement every suggestion, but figure if there is something that might be useful to others, may as well contribute it to the list...
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05-22-2024, 07:21 PM
(This post was last modified: 05-22-2024, 07:22 PM by SpriggsySpriggs.)
I had GPT4 write it. I just asked it to create a cross platform C function to grab last modified date/time.
I would have used GPT4o but I saw that someone had made a code-specific GPT on the GPT Store so I went with that instead.
Tread on those who tread on you
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05-22-2024, 07:58 PM
(This post was last modified: 05-22-2024, 07:59 PM by Ed Davis.)
(05-22-2024, 06:42 PM)SpriggsySpriggs Wrote: Quote:Sure, let's create a function in C that retrieves the last modified date and time of a file in a cross-platform manner. We'll use the standard library functions available in C for both Unix-like systems (Linux, macOS) and Windows.
### Plan
1. **Include necessary headers**: We need to include different headers depending on the platform.
2. **Define the function**: The function `get_last_modified_time` will take a file path as an argument.
3. **Platform-specific code**:
- For Unix-like systems, we'll use `stat` to get the file's metadata.
- For Windows, we'll use `GetFileAttributesEx` to get the file's metadata.
4. **Format the output**: We'll format the output to display the last modified date and time.
Here’s the complete C code:
```c
#include <stdio.h>
#include <time.h>
#ifdef _WIN32
#include <windows.h>
#else
#include <sys/stat.h>
#endif
void get_last_modified_time(const char *filepath) {
#ifdef _WIN32
WIN32_FILE_ATTRIBUTE_DATA fileInfo;
if (GetFileAttributesEx(filepath, GetFileExInfoStandard, &fileInfo)) {
FILETIME ft = fileInfo.ftLastWriteTime;
SYSTEMTIME st;
FileTimeToSystemTime(&ft, &st);
printf("Last modified date and time: %02d/%02d/%d %02d:%02d:%02d\n",
st.wDay, st.wMonth, st.wYear,
st.wHour, st.wMinute, st.wSecond);
} else {
printf("Failed to get file attributes for %s\n", filepath);
}
#else
struct stat attr;
if (stat(filepath, &attr) == 0) {
struct tm *tm_info = localtime(&attr.st_mtime);
char buffer[30];
strftime(buffer, 30, "%Y-%m-%d %H:%M:%S", tm_info);
printf("Last modified date and time: %s\n", buffer);
} else {
perror("stat");
}
#endif
}
int main() {
const char *filepath = "path/to/your/file.txt";
get_last_modified_time(filepath);
return 0;
}
```
### Explanation
1. **Headers**:
- `stdio.h` for input/output functions.
- `time.h` for time manipulation.
- `windows.h` for Windows-specific file attributes.
- `sys/stat.h` for Unix-like system file attributes.
2. **Function**:
- `get_last_modified_time` is defined to handle both Unix-like and Windows systems.
- On Windows, `GetFileAttributesEx` is used to get file information and `FileTimeToSystemTime` to convert it to a readable format.
- On Unix-like systems, `stat` is used to get file information and `localtime` to convert the last modification time to a readable format.
3. **Main Function**:
- Example usage with a placeholder file path.
- Call to `get_last_modified_time` to print the last modified date and time.
### Suggestions for Next Steps
**a.** Add error handling for different edge cases (e.g., file not found, permission issues).
**b.** Modify the function to return the last modified date and time as a string instead of printing it.
No big deal, but since QB64PE uses gcc/g++ for Windows, you don't need the "#ifdef WIN32" part, since stat() also works on Windows.
For instance, this:
Code: (Select All) #include <stdio.h>
#include <time.h>
#include <sys/stat.h>
void get_last_modified_time(const char *filepath) {
struct stat attr;
if (stat(filepath, &attr) == 0) {
struct tm *tm_info = localtime(&attr.st_mtime);
char buffer[30];
strftime(buffer, 30, "%Y-%m-%d %H:%M:%S", tm_info);
printf("Last modified date and time: %s\n", buffer);
} else {
perror("stat");
}
}
int main(int argc, char *argv[]) {
const char *filepath = argv[1];
if (argc < 2) {
printf("Usage: foo filename\n");
} else {
get_last_modified_time(filepath);
}
return 0;
}
Compiles and runs under Windows.
Again, no big deal, just a friendly FYI.
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(05-22-2024, 07:21 PM)SpriggsySpriggs Wrote: I had GPT4 write it. I just asked it to create a cross platform C function to grab last modified date/time.
I would have used GPT4o but I saw that someone had made a code-specific GPT on the GPT Store so I went with that instead. Wow that's great!
Do you think GPT will help the QB64PE devs in general?
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05-22-2024, 10:03 PM
(This post was last modified: 05-22-2024, 10:04 PM by SMcNeill.)
(05-22-2024, 06:20 PM)madscijr Wrote: (05-22-2024, 05:04 PM)SpriggsySpriggs Wrote: I guess I'm going to have to become the old geezer who complains that everyone is ruining hard drives with temp files constantly. Ha!
Well in this case I was looking to see if a file changed on disk, and only access it if it changed.
I figured looking at the timestamp and size in bytes are a good way to tell.
The problem with using this SHELL method that creates a file is, it requires at least 3 disk accesses:
- one to read the attributes
- one to write them to a temp file, and
- one to read that file
- (and another if we want to delete the temp file)
Not too efficient. For a lot of cases that might not be a big deal, but for what I'm doing, it would slow things down a lot.
We have a thread somewhere to suggest new commands for QB64PE, right? Where can I suggest adding some built-in cross-platform commands to get a file's date / size / attributes (& maybe update them as well)? Note that you can use wmic to get all sorts of attribute information on your files, easily from the command line:
Code: (Select All) AccessMask=1507775
Archive=FALSE
Caption=Z:\foo.pdf
Compressed=TRUE
CompressionMethod=Compressed
CreationClassName=CIM_LogicalFile
CreationDate=20240518233126.540393-240
CSCreationClassName=Win32_ComputerSystem
CSName=LAPTOP
Description=Z:\foo.pdf
Drive=z:
EightDotThreeFileName=z:\foo.pdf
Encrypted=FALSE
EncryptionMethod=
Extension=pdf
FileName=foo
FileSize=34339
FileType=pdf File
FSCreationClassName=Win32_FileSystem
FSName=NTFS
Hidden=FALSE
InstallDate=20240518233126.540393-240
InUseCount=
LastAccessed=20240522175359.607566-240
LastModified=20240501171800.893675-240
Manufacturer=
Name=Z:\foo.pdf
Path=\
Readable=TRUE
Status=OK
System=FALSE
Version=
Writeable=TRUE
All from this simple program: Code: (Select All) $Console:Only
Shell "wmic DataFile where " + Chr$(34) + "Name='Z:\\foo.pdf'" + Chr$(34) + " list /format:list"
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05-22-2024, 10:22 PM
(This post was last modified: 05-23-2024, 09:18 PM by madscijr.
Edit Reason: fixed typo
)
(05-22-2024, 10:03 PM)SMcNeill Wrote: Note that you can use wmic to get all sorts of attribute information on your files, easily from the command line:
That's good to know, and gives me a "bright idea", LoL.
Actually this might be useful for a bunch of things, not just this...
What about a command (or option / flag) that runs a command prompt, but instead of piping the output to a file, it goes straight into memory, and populates a string variable?
That would simplify things a little.
Either way, that wmic can come in handy.
What about the Mac/Linux equivanent?
And what can be used to update a file's attributes?
Say you want to alter a file's Modified Date, or make it read only or writable?
Thanks for sharing the wmic info.
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madscijr, it sounds like you want to use pipecom
Tread on those who tread on you
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(05-23-2024, 03:33 PM)SpriggsySpriggs Wrote: madscijr, it sounds like you want to use pipecom Ah yes...
Check out the current iteration of the multi mouse in works in progress - would pipecom be appropriate for that?
If you have a minute, send a link to the pipecom page again and any examples that demonstrate it, that would be grear
t. Thanks
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In Visual Basic (Excel, Word... MSOffice) you have, for this job:
MySize = FileLen("TESTFILE")
MyStamp$ = FileDateTime("TESTFILE") ' Returns ... "18/10/2019 11:55:27".
Perhaps one day theese commands will exist in QB64
Why not yes ?
|