用C代码在服务器上写一个简单的Flat文件

Question

I have the following code of C, which will sent me email notification for error.

Now what i looking for , to Create a flat file on Unix server itself for all those error message's.

   /*  write the formatted message to the temp email file and close the file.
*/
    fputs(szEmailMsg, fpTmpMsgFile);
if (ferror(fpTmpMsgFile)) {
    dce_dbgwrite(DCE_LOG_ERROR,
        "Child %d: write to %s for email message failed: %s", iThisChild,
        pszTmpMsgFile, strerror(errno));
    dce_dbgwrite(DCE_LOG_ERROR, "Child %d: email message = <%s>",
        iThisChild, szEmailMsg);
    return;
}
fclose(fpTmpMsgFile);
/*  email the message and remove the temp email file.
*/
    sprintf(szCmd,
     "/usr/bin/mail -s\"lg_a17_srvr error\" %s < %s",
       pszSupportAddr, pszTmpMsgFile);
      if (system(szCmd) != 0) {
        dce_dbgwrite(DCE_LOG_ERROR,
          "Child %d: command to email error message failed: %s", iThisChild,
        strerror(errno));
    dce_dbgwrite(DCE_LOG_ERROR, "Child %d: email command = %s", iThisChild,
        szCmd);
    dce_dbgwrite(DCE_LOG_ERROR, "Child %d: email message = <%s>",
        iThisChild, szEmailMsg);
}
remove(pszTmpMsgFile);
}

this pszTmpMsgFile file contains those information, want to add code just before its removlable to create new file name like >> error.log which contain all the information of this file and send it to different unix dir... say : home/bin/letgen Thanks in advance !!!

Answer 1

You have not provided enough detail for me to understand exactly what your code is doing (for example, what does dce_dbgwrite() do? Does it write to a file? Database?). Without that information, I can't fully answer your question, but I will leave the following example for what I think you are asking.

If I understand your question correctly, you want to write the error string szEmailMsg to an error file called error.log . You also want the log to exist in two locations.

The following function will append a string to a file. If the file does not exist, it will be created.

#include <stdio.h>

void append_data_to_file(const char* path, const char* data)
{
    // Open the file to append data, creates file if it does not exist.
    FILE f = fopen(path, "a");

    // Only continue if the previous statement succeeded 
    if (f != NULL)
    {
        // Write (append) the data to the file
        fputs(data, f);

        // Close the file
        fclose(f);
    } else {
        printf("Failed to open file %s", path);
    }
}

Then, you can create the following wrapper function to write the log file:

void log_error(const char* data)
{
    // Write to the normal error log
    append_data_to_file("error.log", data);

    // Add a new line for formatting, to prevent logs from being bunched up together
    // This part is optional. \n means new line.
    append_data_to_file("error.log", "\n\n");

    // The second location
    append_data_to_file("home/bin/letgen/error.log", data);
    append_data_to_file("home/bin/letgen/error.log", "\n\n");
} 

To log an error, just add this now:

log_error(szEmailMsg);

I have not tested any of this code , but you should get the general idea of what to do.