more about gdbinit

[remove CAPS]

hi again everyone,

i've been thinking more about the code i was looking at this past 
weekend. there's a bit of logic that goes something like the following:

"if there's a '.gdbinit' in the current directory read and process it, 
unless it's the same as the one in the user's $HOME directory"

i've talked about this in a past email. basically the if() condition 
isn't strong enough, if you change the third parameter to 
'catch_command_errors()' from "0" to "!batch" you'll see some error 
output.

as it currently stands, even if the file in the current directory 
doesn't exist that is considered sufficiently different from the one in 
the $HOME directory to allow this code to execute (which, of course, if 
the file doesn't exist, it shouldn't!)

i think a good C function to call here is "access". if you pass the 
constant "F_OK" as the mode, the "access" function will basically check 
to see if you can access this file, "F_OK" just checks to make sure the 
file exists. we could also OR "F_OK" with "R_OK" to make sure that we 
can also read this file.

the logic that is used to check to see if the two files are different 
involves the use of the "stat" function. the entire structure the 
"stat" function fills in is checked (using "memcmp"), but this 
structure also gives information about inodes and other such stuff. 
what i'm pointing out is that the one file would have to be a link to 
the other in order for them to compare equal. so if you have two 
distinct files, each of which has the exact same contents, the 
comparison will show that they are different. i believe the original 
intent was that the init file in the current directory should only be 
processed if its contents aren't the same as the contents of the init 
file in the $HOME directory.

so is there a C function that will compare the contents of two files? i 
don't think so (but i could be wrong of course). i'd gladly write up 
such a little function and provide it if anyone cares. i've added the 
call to "access" in my own version, but without the check for file 
differences it doesn't amount to much.

best regards,
        trevor

ps. again, sorry for mangling my email, just remove the caps if you 
want to reply personally.
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