Thread: gtk+: g_base64_encode vs g_base64_decode

These two functions aren't "the same, only oposite", it seems?

In the following example, two strings are picked from two gtktentry fields:

Code:

const gchar *plaintext;
const gchar *b64text;
       	
plaintext = gtk_entry_get_text(GTK_ENTRY(cwidgets->plainentry));
b64text = gtk_entry_get_text(GTK_ENTRY(cwidgets->b64entry));

gtk_entry_set_text(GTK_ENTRY(cwidgets->b64entry), g_base64_encode(plaintext, g_utf8_strlen(plaintext, 256)));

gtk_entry_set_text(GTK_ENTRY(cwidgets->plainentry), g_base64_decode(b64text, g_utf8_strlen(b64text, 256)));

The g_base64_encode line compiles fine, without warnings.

However, the g_base64_decode line gives this warning:

Code:

warning: passing argument 2 of ‘g_base64_decode’ makes pointer from integer without a cast

The data for the two functions are the same, so they must be expecting different data formats?

Any hints?

Base64 Encoding

One takes a gchar pointer and the other a guchar pointer.

Sorry, I'm new and struggling with some of this. (But I THINK I'm learning :-)

When all I want to do is to take one string and decode it, how am I going to do this? If this function only returns a length, where's the decoding?

The return value of g_base64_decode is the decoded text (guchar is a typedef for unsigned char). Note that you are responsible for freeing the returned memory.

Code:

guchar *result;
gsize result_len;
result = g_base64_decode(encoded_text, &result_len);

This just gets more and more confusing.

This code works (gives no warnings):

Code:

const gchar *enc[32];			// WHY MUST I USE const? Gives warning if not used.
enc[32] = gtk_entry_get_text(GTK_ENTRY(cwidgets->b64entry));

It seems to work like I want: Take the text from the GtkEntry and put it into the gchar variable.

However, when I try to put the gchar variable into another GtkEntry, then it's suddenly incompatible:

Code:

const gchar *enc[32];			// WHY MUST I USE const? Gives warning if not used.
enc[32] = gtk_entry_get_text(GTK_ENTRY(cwidgets->b64entry));	
gtk_entry_set_text(GTK_ENTRY(cwidgets->plainentry), enc);

Then it suddenly gives this error:

Code:

warning: passing argument 2 of ‘gtk_entry_set_text’ from incompatible pointer type

Never mind. I must be drunk.