Read text file line by line and write lines to other files

Hello,
How can read the file /var/etc/allInOne.cfg and split it into mltiple cfg files.

the source file "/var/etc/allInOne.cfg "look like this:

line1
line2
...
line10
filePath:/var/etc/file1.cfg
line12
line13
...
line14
filePath:/var/etc/file2.cfg
linen
..
filePath:/var/etc/filen.cfg

Code:

void genCfg(int err)
{
// create a buffer to read the allInOne.cfg.
char buf[512];
char linesbuf[2048];;
// declare the variables we will use in this function
// open temporary file cotaining the data 
FILE *f = fopen("/var/etc/allInOne.cfg", "rt");
if (f)
{
 while (fgets(buf, 512, f)
 {
 // if we found this string the we can stop to read and create the cfg file then continue the read
 if (strstr(buf, "filePath:")) {
                                FILE *fp;
                                fp = fopen(buf,"w"); //the buf contain the path and filename
                                /*Create a file and add text*/
                                printf(fp,"%s",lines); /*writes data to the file*/
                                fclose(fp); /*done!*/
                                lines = ""; initialize lines for next cfg file
 }
 else 
  //store the line in the variable		       
  lines += buf;
}
// close file
fclose(f);
return 0
}
}

Code:

char lines;

That's room for one character. You seem to need to study up on C strings, because that, along with

Code:

lines += buf

is very wrong.

thanx for the reply,
can you help me to make this function work properly please.

Originally Posted by magische_vogel

thanx for the reply,
can you help me to make this function work properly please.

Type "man string" at your terminal.

Originally Posted by tabstop

Type "man string" at your terminal.

i'm a newbie, can you explain how to read the path from the buf variable and pass it to the fopen function.

best regards.

strcpy will copy one string to another. You need to set a pointer to the beginning of the filepath, i.e., after the colon to mark the spot to start copying from.

Originally Posted by tabstop

strcpy will copy one string to another. You need to set a pointer to the beginning of the filepath, i.e., after the colon to mark the spot to start copying from.

Where is C or C++ Coders? can i see a snipet code on how to do that.I'm doing my best to solve it myself but i can't.

Originally Posted by magische_vogel

Where is C or C++ Coders? can i see a snipet code on how to do that.I'm doing my best to solve it myself but i can't.

As a matter of fact, some of the very best are right here...

You want to know how to copy a string to a string... look up strcpy() as suggested in your C library documentation.

To locate the : and get your starting point you probably want something like strchr() which you should also look up in your docs...

Originally Posted by CommonTater

As a matter of fact, some of the very best are right here...

You want to know how to copy a string to a string... look up strcpy() as suggested in your C library documentation.

To locate the : and get your starting point you probably want something like strchr() which you should also look up in your docs...

How to make this function work and create the target file :
rename("/var/tmp/temp.cfg", line); //not working

Code:

FILE *fsp,*fdp;
           char *line = NULL;
           size_t len = 0;
           ssize_t read;

           fsp = fopen("/var/etc/allInOne.cfg ", "r");
           fdp = fopen("/var/tmp/temp.cfg", "w");
           if (fsp == NULL)
               exit(EXIT_FAILURE);
           if (fdp == NULL)
               exit(EXIT_FAILURE);

           while ((read = getline(&line, &len, fsp)) != -1) {
                  //printf("Retrieved line of length %zu :\n", read);
                  //printf("%s", line);
               if (strstr(line, "/var/")) {
                  //Close the fdp file
                  fclose(fdp);
                  //get the path from line here
                  //how can i extract the path here and pass it to the rename function 
                  //Move the temp file 
                  rename("/var/tmp/temp.cfg", "/var/etc/file1.cfg"); //work good 
                  //rename("/var/tmp/temp.cfg", line); //not working
                  //Delete the temp file
                  remove("/var/tmp/temp.cfg"); 
                  //open the temp file                       
                  fdp = fopen("/var/tmp/temp.cfg", "w");
                  if (fdp == NULL)
                   exit(EXIT_FAILURE);
               }
               else {
                 fprintf(fdp,"%s",line); /*writes data to the file*/
               }
           }
           //close the source file
           fclose(fsp);
           fclose(fdp);
           //free the pointer line
           free(line);

This is how you could do in awk.

Code:

/^filePath:/ {
     split($0,a,":");
     outfile = a[2]
     for(i=0;i < n;i++) {
       print lines[i] > outfile
     }
    close(outfile)
    n = 0
    next
 }
  { lines[n++] = $0; }

For your c code, getline will also read '\n' in your buffer.

Originally Posted by Bayint Naung

This is how you could do in awk.

Code:

/^filePath:/ {
     split($0,a,":");
     outfile = a[2]
     for(i=0;i < n;i++) {
       print lines[i] > outfile
     }
    close(outfile)
    n = 0
    next
 }
  { lines[n++] = $0; }

For your c code, getline will also read '\n' in your buffer.

How to skip the '\n' in my buffer (line)?