如何在C中将多行写入输出文件？

Question

I am new to file operations like write/read in C. Is there a solution to write all printf() which is below, to my output text file? After execution I was not able to write all the lines to my text file.

for(i=0;i < n;i++)
    if(i!=startnode)
    {
        outputFile = fopen(myOutputFile, "w");

        printf("\nCOST of %d = %d", i, cost[i]);
        printf("\nTRACE = %d", i);

        j=i;
        do
        {
            j=pred[j];
            printf(" %d", j);

        }
        while(j!=startnode);
    }

Answer 1

You can use fprintf(FILE * stream, const char * format, ... ) and pass the file handle to the function.

for(i=0;i < n;i++)
    if(i!=startnode)
    {
        outputFile = fopen(myOutputFile, "a");

        fprintf(outputFile,"\nCOST of %d = %d", i, cost[i]);            
        fprintf(outputFile,"\nTRACE = %d", i);

        j=i;
        do
        {
            j=pred[j];
            fprintf(outputFile," %d", j);

        }
        while(j!=startnode);
       fclose(outputFile);
    }

Edit according to your comment:

According to your comment update the mode you are opening the file to: fopen("asdas","a")

Answer 2

Try this:

outputFile = fopen(myOutputFile, "a");
for(i=0;i < n;i++)
    if(i!=startnode)
    {    
        fprintf(outputFile,"\nCOST of %d = %d", i, cost[i]);            
        fprintf(outputFile,"\nTRACE = %d", i);

        j=i;
        do
        {
            j=pred[j];
            fprintf(outputFile," %d", j);

        }
        while(j!=startnode);
    }

Answer 3

Try this:

freopen(myOutputFile, "a+",stdout);  //Redirect the standard output to file, "a+" - is for appending info if the file is has data before it is openned
for(i=0;i < n;i++)
{        
    if(i!=startnode)
    {
        printf("\nCOST of %d = %d", i, cost[i]);            
        printf("\nTRACE = %d", i);

        j=i;
        do{
            j=pred[j];
            printf(" %d", j);

        }while(j!=startnode);
    }
}