strcat and memory

[cmancre]

code:
char *command=(char*)malloc(1024*sizeof(char));
char *tmp=(char*)malloc(10*sizeof(char));
memset(tmp,0,10);
tmp = strcat(tmp,"123456789");
.
.
.
fprintf(stdout,"\nbefore %s",tmp);
command=strcat(strcat(strcat(var1,var2),var3),var4);
fprintf(stdout,"\n%s",command);
fprintf(stdout,"\nafter %s",tmp);

problem:
tmp points that string numbers, and is never used till the other part of the code, the first printf prints correct the string, the variable command is also good to, bue the second time showing tmp it shows part of the command string, why is this???

 

[cpjust]

I'm guessing it has to be:

command=strcat(strcat(strcat(var1,var2),var3),var4);

Try commenting out that line and see what happens.
If that solves the tmp corruption problem you'll have to look closer at var1, 2, 3 & 4...

 

[Salem]

> tmp it shows part of the command string, why is this???
Because you overflowed your string.

Without seeing how you declared your var1 to var4 variables, your post makes no sense.

> command=strcat(strcat(strcat(var1,var2),var3),var4);
Since you didn't strcat to command in the innermost call, you've just lost the memory you allocated.

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