Teach me to remove bloat!

Hey guys, I would like some pointer (no, not that kind) on removing bloat in code. Here is a fully functional piece of code that I wrote which I'm worried about bloat in. How do I shorten this?

int get_input()
{
    int count, paren_count, total_count, c;
    char *input, *temp;

    input = (char *) malloc (500 * sizeof (char));

    if (input == NULL) return 0;
    printf("%% ");
    for (count = paren_count = total_count = 0; (c = getchar()) != EOF; count++, input++, total_count++)
    {
        if (count == 499)
        {
            input -= total_count;
            temp = (char *) realloc (input, (500 + total_count) * sizeof (char));
            if (temp == NULL)
                return 0;
            input = temp;
            input += total_count;
        }
        if (c == '\n')
        {
            *input = '\0';
            temp = input;
            temp -= (count);
            count = 0;
            for (; *temp != '\0'; temp++)
            {
                if (*temp == '(')
                    paren_count++;
                else if (*temp == ')')
                    paren_count--;
            }
            if (paren_count == 0)
                break;
            printf("  ");
        }
        *input = c;
    }
    *temp = '\0';
    input -= total_count;
    printf("%s\n", input);
    free(input);
    return 0;
}

here, OP, let me help you with the first step:


int get_input()
{
    int count, paren_count, total_count, c;
    char *input, *temp;

    input = (char *) malloc (500 * sizeof (char));

    if (input == NULL) return 0;
    printf("%% ");
    for (count = paren_count = total_count = 0; (c = getchar()) != EOF; count++, input++, total_count++)
    {
        if (count == 499)
        {
            input -= total_count;
            temp = (char *) realloc (input, (500 + total_count) * sizeof (char));
            if (temp == NULL)
                return 0;
            input = temp;
            input += total_count;
        }
        if (c == '\n')
        {
            *input = '\0';
            temp = input;
            temp -= (count);
            count = 0;
            for (; *temp != '\0'; temp++)
            {
                if (*temp == '(')
                    paren_count++;
                else if (*temp == ')')
                    paren_count--;
            }
            if (paren_count == 0)
                break;
            printf("  ");
        }
        *input = c;
    }
    *temp = '\0';
    input -= total_count;
    printf("%s\n", input);
    free(input);
    return 0;
}

Use a better language, I guess.

(defun get-input (&optional (stream *terminal-io*))
  (with-output-to-string (input)
    (prog (i (p 0))
     loop
     (setf i (read-line stream nil nil)
           p (+ p (count-parens i)))
     (write-string i input)
     (if (or (null i)
             (zerop p))
         (return)
         (go loop)))))

(defun count-parens (string)
  (loop for x across string
     summing (case x
               (#\( 1)
               (#\) -1)
               (t 0))))

>>3
I'm trying to write the shell for an interpreted language, it wouldn't make much sense to write it in another interpreted language.

int getInput() {
    int size = 500, count = 0;
    char* input = malloc(size * sizeof(char)), c;
    printf("%% ");
    for(;(c=getchar())!=EOF; ++count) {
        if(count>=size-1) {
            size *= 2;
            input = realloc(input, size * sizeof(char));
        }
        input[count] = c;
        if(c=='\n') {
            input[count+1]='\0';
            if(!countParens(input)) break;
            printf("  ");
        }
    }
    input[count] = '\0';
    printf("%s\n", input);
    free(input);
    return 0;
}
int countParens(const char* s) {
    int n = 0;
    for(;*s;s++) n += *s=='('?1:*s==')':-1:0;
    return n;
}

>>4
Then you need more FIOC.

>>4
Lisp ... interpreted
Wut.

This must be a troll. Your program is a borderline IOCCC case. Read K&R.

>>5
Your unidiomatic use of for loops makes me sick.

UNTeSTED


int get_input() {
    int n,p,t,c;
    char *inp,*tmp;

    if(!(inp=malloc(500))
      return 0;

    printf("%% ");
    for(n=p=t=0;(c=getchar())!=EOF;n++,inp++,t++) {
        if(count==499) {
            inp -= t;
            if(!(tmp=realloc(inp,500+t))
              return 0;
            inp = tmp + t;
        }
        if(c=='\n') {
            *input = 0;
            tmp = inp;
            tmp -= n;
            n = 0;
            for(;*tmp!='\0';tmp++)
                p+=(*tmp=='(')?1:((*tmp==')')?-1:0);
            if(!p)
                break;
            printf("  ");
        }
        *inp = c;
    }
    *tmp = 0;
    inp -= t;
    printf("%s\n",inp);
    free(inp);
    return 0;
}

First of all, remove all the useless white spaces. Also change all of your variable names to shorter ones.

int get_input(){int u,p,t,c;char *i,*m;i=(char*)malloc(500*sizeof(char));if(i==NULL)return 0;printf("%% ");for(u=p=t=0;(c=getchar())!=EOF;u++,i++,t++){if(u==499){i-=t;m=(char*)realloc(i,(500+t)*sizeof(char));if(m==NULL)return 0;i=m;i+=t;}if(c=='\n'){*i='\0';m=i;m-=(u);u=0;for(;*m!='\0';m++){if(*m=='(')p++;else if(*m==')')p--;}if(p==0)break;printf("  ");}*i=c;}*m='\0';i-=t;printf("%s\n",i);free(i);return 0;}

ENTERPRISE QUALITY OMPIMIZATION

>>11
FrozenVoid Quality.

>>11
ZOMG OPTIMISED
#define return R
#define printf P
int g(){int u,p,t,c;char *i,*m;i=(char*)malloc(500*sizeof(char));if(i==0)R 0;P("%% ");for(u=p=t=0;(c=getchar())!=-1;u++,i++,t++){if(u==499){i-=t;m=(char*)realloc(i,(500+t)*sizeof(char));if(m==0)R 0;i=m;i+=t;}if(c=='\n'){*i='\0';m=i;m-=(u);u=0;for(;*m!='\0';m++){if(*m=='(')p++;else if(*m==')')p--;}if(p==0)break;P("  ");}*i=c;}*m='\0';i-=t;P("%s\n",i);free(i);R 0;}

>>13
You should move the lines
#define return R
#define printf P

to your void.h file.

>>14
I nearly spit my juice^[1] on the keyboard.

_{--------------------------------
¹- On the left in this image: http://www.kagome.co.jp/news/2008/images/090108001.jpg - pretty tasty}

>>14
If we are going to allow modifications we could add a lot more to it
#define GC getchar
#define C  char
#define M  malloc
#define SO sizeof
#define RA realloc
#define I  int
#define B  break
#define F  free
#define P  printf
#define R  return
#define Q  if
#define EF else if
#define FR for
and then have
I g(){I u,p,t,c;C *i,*m;i=(C*)M(500*SO(C));Q(i==0)R 0;P("%% ");FR(u=p=t=0;(c=GC())!=-1;u++,i++,t++){Q(u==499){i-=t;m=(C*)RA(i,(500+t)*SO(C));Q(m==0)R 0;i=m;i+=t;}Q(c=='\n'){*i='\0';m=i;m-=(u);u=0;FR(;*m!='\0';m++){Q(*m=='(')p++;EF(*m==')')p--;}Q(p==0)B;P("  ");}*i=c;}*m='\0';i-=t;P("%s\n",i);F(i);R 0;}

Thne we should replace everything that is >1 letter long with a single character.

>>16
s/modifications/modifications to void.h/

>>16
it's almost as unreadable as perl

>>16
;_; even FV didn't use one char identifiers. This hurts my eyes.

>>16
If we allow a header file we could even OMPTIMIZE even further:

h.h
#define GC getchar
#define C  char
#define M  malloc
#define SO sizeof
#define RA realloc
#define I  int
#define B  break
#define F  free
#define P  printf
#define R  return
#define Q  if
#define EF else if
#define FR for
#define G  I g(){I u,p,t,c;C *i,*m;i=(C*)M(500*SO(C));Q(i==0)R 0;P("%% ");FR(u=p=t=0;(c=GC())!=-1;u++,i++,t++){Q(u==499){i-=t;m=(C*)RA(i,(500+t)*SO(C));Q(m==0)R 0;i=m;i+=t;}Q(c=='\n'){*i='\0';m=i;m-=(u);u=0;FR(;*m!='\0';m++){Q(*m=='(')p++;EF(*m==')')p--;}Q(p==0)B;P("  ");}*i=c;}*m='\0';i-=t;P("%s\n",i);F(i);R 0;}

whatever.c
#include "h.h"

G

>>20
 ______
[ul](-_ -  )[/ul]

>>8
I'm not, and I already have. The plan was to get this to work first and then clean it up.
>>5
Input = realloc (input,...)
Realloc isn't gauranteed to work fool.

>>22
GUARANTEE MY ANUS

>>5 uses exponential instead of linear allocation
>>10 didn't change much
>>11,13,16,20 IOCCC'd versions of OP

int get_input() {
 int len = 0, ulen = 0, pc = 0;
 char *input = 0, c;
 printf("%% ");
 while((c=getchar())!=EOF) {
  if(ulen>=len) {
   input = realloc(input,len+=500);
   if(!input)
    return 0;
  }
  if(c=='\n')
   if(pc)
    putchar(' ');
   else {
    input[ulen++] = 0;
    break;
   }
  else
   pc += (c=='(')?1:(c==')')?-1:0;
  input[ulen++] = c;
 }
 puts(input?input:"");
 free(input);
 return 0;
}

If you replace the putchar(' ') with printf("%*c",pc,' '), you get auto-indentation too.

You could start by using comments...

Congratulations.  We've taken a very modest function and rendered it illegible.

int get_input(void) {
  char* input;      
  int c, n, parens; 
  int incr = 500;   

  // get a buffer for storage
  if (!(input = (char*) malloc(incr)))
    return -1;                       
  n = parens = 0;                    

  // read until EOF or newline with balanced parens
  printf("%% ");                                  
  while ((c = getchar()) != EOF) {                
    if (c == '\n' && parens <= 0)                 
      break;                                      
    input[n++] = c;                               

    // handle parens
    if (c == '(')  
      ++parens;    
    else if (c == ')')
      --parens;      

    // grow buffer
    if (n % incr == 0)
      if (!(input = (char*) realloc(input, n + incr)))
        return -1;                                   
  }                                                  

  // done
  input[n] = 0;
  if (c == EOF) printf("\n");
  printf("%s\n", input);    
  free(input);              
  return c == EOF ? -1 : 0; 
}

- pulls out increment as a constant
- returns -1 on failure (you were returning 0 everywhere for some reason)
- checks for end of file (ctrl+d or closed pipe)
- checks for too many closing parens
- adds CODE COMMENTS, so you can actually see what's going on

>>27
- also, doesn't fuck around with your input pointer, so you can use it with garbage collectors and other analysis tools. It's a little scary that OP doesn't keep a fixed pointer to the start of the buffer.

>>28
fag

is this a side effect generator?

>>26

illegible
Isn't it the real point of /prog/?

GRUNNUR

>>25
You seriously need comments to understand this?

This does a lot more than you want it to do, but it's more generic:
(read)

>>22
You think I give a shit if realloc works or not? You think his program is going to be able to gracefully degrade if it runs out of memory? Get the fuck out with your useless pedantry.

>>35
My program? Frankly, I like protection.
Anyway today I fixed the bloat issue. I'll post it later for show.

>>36
Those who give up efficiency for security deserve neither.

>>37
Okay here's the thing: I am writing an interpreted programming language, this function is part of the shell.
God damn, I need to free all of the memory in the linked list before it exits, or else bad things will happen, and you know it.

>>38
Why don't you just write it in a higher level language? Until you have it working, worrying about efficiency is a waste.

>>39
I hate higher level languages in general (save for languages like scheme and perl), plus the linked lists are so much easier in C. And you're right, worrying about efficiency in the beginning is stupid, I was just saying how safety is necessary for what I'm doing.

Any way, here's my fixed version. Sorry if I don't get the bbcode right

int get_input()
{
    int count, post_count;
    char *input = NULL, *temp, c;

    printf("%% ");
    for (count = 0; (c = getchar()) != EOF; count++)
    {
        if (count % 500 == 0)
        {
            if ((temp = (char *) realloc (input, (500 + count) * sizeof (char))) == NULL)
            {
                free (input);
                return 2;
            }
            input = temp;
        }
        input[count] = c;
        if (c == '\n')
        {
            input[count + 1] = '\0';
            temp = input;
            post_count = 0;
            while (*temp != '\0')
            {
                if (*temp == '(')
                    post_count++;
                else if (*temp == ')')
                    post_count--;
                temp++;
            }
            if (post_count > 0)
                printf("  ");
            else
                break;
        }

    }
    printf("%s\n", input);
    free(input);
    return 0;
}