How to remove ^M ^J characters in linux - c

Question

I have an external machine which send me results in my Raspberry pi. In my emulator Cutecom I have the results line by line without problems. I use Codeblocks and I wrote my own C application to read these data every 10 seconds. But something strange happens. Sometimes I have the results line by line and sometimes I have the strange characters ^M ^J at the end of each line and as a result I have terrible finals results. I think that these EOF characters are because the external machine has developed in Windows.
The good results
+PARAMETERS: 45 BYTES FROM 0000:0000 (063)
MACHINE_1:(AN=23.45,H=34.56,D=12.34)
The bad results
+PARAMETERS: 45 BYTES FROM 0000:0000 (063)^M^JMACHINE_1:
(AN=21.45,H=33.56,D=10.34)
Ok, until here the only problem is the way the command line shows the result but my results are ok. But if I try to use strtok to get some tokens then I have serious problems because of these characters. What can I do? Can I add something to escape these characters?This is the part of the code which I use to read data from the machine
char buff[300];
memset(buff, 0, sizeof(buff));
for (;;)
{
n=read(fd,buff,sizeof(buff));
sleep(1);
printf("%s", buff);
printf("\n");
....
....

Answer 1

You're just reading blocks of 300 characters, so there is no string termination \0.
You'll have to look at n to see how much data you have read and then process the data before printing it i.e. look for the ^J^M and terminate the line,then continue reading the rest of the data.
FYI ^J^M is Windows line termination (it's just ^J form linux)
The following should read multiple messages and convert ^ and J to \n and ignore ^M.
Note this uses STDIN, not a serial port.
#include <stdio.h>
#include <unistd.h>
int main(int argc, char** argv)
{
int fd=STDIN_FILENO;
int i,n;
int c=0;
char buff[300];
memset(buff, 0, sizeof(buff));
for (;;)
{
n=read(fd,buff,sizeof(buff));
for (i=0; i<n; i++)
{
switch(buff[i])
{
case '^':
if(c)
{
// ^^ so output first ^
putchar('^');
}
else
{
// Possible ^M or ^J
c++;
}
break;
case 'M':
if (c)
{
// ignore ^M
c=0;
}
else
{
// just M
putchar(buff[i]);
}
break;
case 'J':
if (c)
{
// ^J is \n
putchar('\n');
c=0;
}
else
{
// just J
putchar(buff[i]);
}
break;
default:
if (c)
{
// ^ followed by other than J or M
putchar('^');
c=0;
}
putchar(buff[i]);
}
}
}
return 0;
}

Answer 2

I think you can still use strtok() with this. Just add ^M and ^J in the char *delimiters parameter.

Answer 3

Just execute the command "sed -e 's/\^\M$//g' filename"
or I got this from the website.
#!/usr/bin/python
while True:
file = raw_input('Input file name:(input "q" to quit)')
if file == 'q':
break
file_ = open(file).read()
list_ = list(file_)
new_file = ''
for x in list_:
if x != '^' and x != 'M':
new_file = new_file + x
file_ = open(file,'w')
file_.write(new_file)
file_.close()