krpors / hx Goto Github PK

Would you like to add more error handling for return values from functions like the following?

• fclose ⇒ editor_writefile
• malloc ⇒ editor_newfile
• sigaction ⇒ main

A great milestone would be to make hx comply with the Debian packaging standard and such, so it can eventually be included into their repository.

The comments in the project use /** which is used by tools like doxygen to distinguish between normal comments and comments which are designed to be used for generating documentation. This can confuse certain syntax highlighting and if the project ever wishes to switch to doxygen (unlikely because this is not a library but who knows) then this will need to be done anyway.

Additionally some multi line comments are done using C99 style // comments. It might be worthwhile to switch to using one style throughout the project if the comments are to be changed to normal /* comments.

To reproduce:

1. Open file with hx.
2. Type / to search for a string which does not occur in a file (e.g. akljahlekfahlkdjfh)
3. Hit N to search backwards
4. Segmentation fault occurs.

Backtrace:

#0  __memcmp_ssse3 () at ../sysdeps/x86_64/multiarch/memcmp-ssse3.S:1933
#1  0x0000000000402743 in editor_process_search (e=e@entry=0xfc5010, str=<optimized out>, str@entry=0xfc511c "asdfklj", dir=dir@entry=SEARCH_BACKWARD) at editor.c:740
#2  0x0000000000402e92 in editor_process_keypress (e=0xfc5010) at editor.c:923
#3  0x00000000004012de in main (argc=0x2, argv=<optimized out>) at hx.c:177

Not sure if it's just my machine or not... backspace does not seem to work. Changing KEY_BACKSPACE to 0x08 (\b in the ASCII table actually) seems to work fine for me.

Not much to say as this this shows it all.

I wouldn't mind giving non-ASCII byte searching a shot. Though I'm not sure what the intented syntax is. editor.c seems to imply any search string starting with "0x" should be regarded as a hex byte sequence though of course this means searching for "0x" is impossible.

Here are the options I think could be possible... the existing input buffer size is 80 and I might make reference to that.

A separate search command
That is, instead of /, some other key.
Advantages

• Straightforward to implement (convert typed bytes into actual bytes and use existing search process)
• No extra typing (i.e. no need for \x or 0x) so 40 bytes fit
• No need for a character to become an escape character

Disadvantages

• Not possible to mix bytes and ASCII without typing the hex ASCII value ((e.g. 41 instead of A)
• Creates a separate command

\x regards the entire search stirng as byte values
So "/\xabcf" searches for 0xab follow by 0xcf.
Advantages

• Uses same command
• No extra typing past initial "\x", so 39 bytes fit

Disadvantages

• Not possible to mix bytes and ASCII without typing the hex ASCII value
• \ becomes an escape character - though if \ appears in a position after the first, it's not an issue.

\x regards the following two bytes as a byte value
So "/a\x41b" searches for a followed by 0x41 followed by b.
Advantages

• Can mix ASCII and byte values
• Uses same command
• Pretty simple to explain in documentation

Disadvantages

• \x needs to be typed before every byte value so a maximum of 20 byte values can be searched (or 19 byte values and 4 ASCII characters, and so on)
• \ becomes an escape character anywhere in the string - \ is required to search for \ and ' followed by anything but x or \ is an error that needs to be handled

\x can be replaced by 0x though I think making 0 an escape character would be frustrating as it isn't standard (as far as I've seen at least).

Reading files from the /proc/ filesystem (e.g. /proc/cpuinfo) returns 0 bytes, whereas using cat on it actually works. Ideally these should just be at least read properly.

There is Append ASCII mode, Insert ASCII mode and just plain replace mode without ASCII, can you add this? Thanks.

Just wanted to say that old projects never die. I just made hx my hex viewer in my file manager.

When a file's contents is emptied (by deleting all bytes), and the a command is used to append a byte, a segfault occurs.

In Vim, :wq writes the file and closes (:wq! also works). It would be great to support that command combination in hx also.