rem: int n = 0;
add: unsigned n = 0; dst[0] = '\0';
context: int read_cmdline(char *restrict const dst, unsigned sz, unsigned pid){    char name[32];    int fd;    int n = 0;    snprintf(name, sizeof name, "/proc/%u/cmdline", pid);    fd = open(name, O_RDONLY);    if(fd==-1) return NULL;    dst[0] = '\0';    for(;;){        ssize_t r = read(fd,dst+n,sz-n);        if(r==-1){            if(errno==EINTR) continue;            break;        }        n += r;        if(n==sz) break; // filled the buffer        if(r==0) break;  // EOF    }    if(n){        int i;        if(n==sz) n--;        dst[n] = '\0';        i=n;        while(i--){          int c = dst[i];          if(c<' ' || c>'~') dst[i]=' ';        }    }    return n;}