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Full Discussion: Unclear pointer and array
Top Forums Programming Unclear pointer and array Post 302884176 by yifangt on Saturday 18th of January 2014 06:25:14 AM
Old 01-18-2014
Thanks Akshay!
So the problem is, at Line 40 &41 of my code, the pointers (*text, *a) that were only declared but not allocated to memory, while the arrays text[100], and a[100] are allocated to memory automatically when they were declared. Is my understanding right? I do not have clear ideas on these points.
And, when I tried your suggestion:
Code:
char *text=(char*)malloc(64);
    char *a=(char*)malloc(64);

There is a bug that seems to be related to the memory allocation.
Code:
$ ./a.out thisisatest 0 6
substring = "thisis"
$./a.out thisisatest 0 7
substring = "thisisa"
$ ./a.out thisisatest 0 8
substring = "thisisa"
$ ./a.out thisisatest 0 9
substring = "thisisa"
$ ./a.out thisisatest 0 10
substring = "thisisa"

It seems to me *a only gets 7 byte plus '\0' at the end, total 8 bytes. Why not 64 bytes as allocated at Line 41?
Last edited by yifangt; 01-18-2014 at 08:18 AM..
 

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GRUB-RENDER-LABEL(1)                                               User Commands                                              GRUB-RENDER-LABEL(1)

NAME

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SYNOPSIS

       grub-render-label [OPTION...] [OPTIONS]

DESCRIPTION

       Render Apple .disk_label.

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              use FILE as font (PF2).

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SEE ALSO

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