Can anyone make this C program simpler

[SwatiA]

#include<stdio.h>
#include<stdlib.h>
#define MAX 5
/* to take a string input of unknown length from the user and print it*/
void main()
{
int i=0;
char *s;
s=(char *) malloc(MAX);
if(!s)
printf(&quot;memory not available\n&quot;
int c;
while (( (c=getchar())!='\n') && (i < (MAX-1) ) )
s[i++]=c;
s='\0';
int j =MAX;
while((i==j-1))
{
j = j+MAX;
s=(char*) realloc(s,j);
if(!s)
printf(&quot;memory not available\n&quot;
while(c!='\n' && (i < (j-1)))
{
s[i++]=c;
c=getchar();
}
s='\0';
}
printf(&quot;%s\n&quot;,s);
free(s);
}

 

[DucatiST2]

How about:-

#include <stdio.h>

void main()
{
char inpstring[120];

printf(&quot;Please input string\n&quot;
gets(inpstring);
printf(&quot;The string was %s\n&quot;,inpstring);
exit(0);
}

 

[amarg]

But that will give the core dump when string length is more than 120.

 

[DucatiST2]

Ok increase the buffer to 500 that should be more than enough. You must remember that there is a maximum line length that can be entered from the command line.

 

[jamisar]

#include <stdio.h>
int main(int argc, char **argv)
{
char *buff = 0;
int len = 0;
int c;


while((c = getc(stdin)) && c != '\n'){

if(!buff){
if(!(buff = (char *)malloc(1+len))) exit(1);
}else{
if(!(buff = (char *)realloc(buff,1+len))) exit(1);
}

*(buff+len++) = c;
}
*(buff+len) = 0;
printf(&quot;|%s|\n&quot;,buff);
exit(0);
}
-----------
when they don't ask you anymore, where they are come from, and they don't tell you anymore, where they go ... you'r getting older !

 

[SwatiA]

thanks for the response. The response by jamisar(Programmer) has been helpful.
Swati

 

[SwatiA]

taking hint from jamisar(Programmer) I changed my program to:
#include<stdio.h>
#include<stdlib.h>
#define MAX 5
void main()
{
char * s=NULL;
int i=0,c;
int j=MAX;

while( (c=getc(stdin))!='\n')
{
if (!s)
{
if(!(s=(char*)malloc(j)))
exit(1);
}
else if ( i== j-1)
{
j=j+MAX;
s=(char*)realloc(s,j);
if(!(s=(char*)realloc(s,j)))
exit(1);
}
s[i++]=c;
}
s='\0';
printf(&quot;%s\n&quot;,s);
}

 

[jamisar]

it's a very bad practice to:

a) limit programs
b) impose limits to the user working interactively
c) use magic number like 120 or 500

what happen by: prg-name < file-name ?
you will never know what is the appropriate limit
not only for char, but int, arrays, struct and so on
struct xxx qqq[MAX];
who said you MAX is MAX enougth ?
how many progs are core dump, years later, because
of this MAX or a stupid magic-number ?

please, think and work dynamically! or go back to basic.

if you really want to do this way, do it safe
this never core dump:

#define MaxBuff what-you-want /* and USE it */

char buff[MaxBuff+1];

while(fgets(buff,MaxBuff,fd)){
OR:
while(fgets(buff,sizeof(buff),fd)){

PS: i prefer the 1. version -----------
when they don't ask you anymore, where they are come from, and they don't tell you anymore, where they go ... you'r getting older !

 

[jamisar]

swati:
why so complex ??
- your while don't check the NULLER
- the realloc depend from 's' not from 'i'
please don't use ONE char variable names,
suppose you have to change 'i' to 'iii' in a x-thousend
file code, how will you sure do it ?
let main ALLWAYS exit a status.
void main() is STUPID! it will return a random value
what if:
prg-name && echo OK || echo KO
in a shell script ?
-----------
when they don't ask you anymore, where they are come from, and they don't tell you anymore, where they go ... you'r getting older !

 

[chipperMDW]

&quot;void main()&quot; may or may not be stupid, but it's not valid C, so that's reason enough to never use it.