file pointers in gdb

I'm writing some code that does a lot of moving around and manipulating stuff inside files. I have trouble debugging it because so much of it is going on in files and I haven't learned how to see what is inside the files from inside gdb. For example, in a simple program that just opens the file README and reads 4 characters from it (snip indicates where I truncated what gdb wrote): (gdb) b main Breakpoint 1 at 0x80484e6: file hello.c, line 7. (gdb) r Starting program:home-allan-a.out Breakpoint 1, main () at hello.c:7 7 fp = fopen("README","r"); (gdb) n 8 c = fgetc(fp); (gdb) print *fp $1 = {flags = -72539000, IOreadptr = 0x0, IOreadend = 0x0, IOreadbase = 0x0, IOwritebase = 0x0, IOwriteptr = 0x0, IOwriteend = 0x0, IObufbase = 0x0, IObufend = 0x0, IOsavebase = 0x0, IObackupbase = 0x0, IOsaveend = 0x0, markers = 0x0, chain = 0x4014abe0, fileno = 5, blksize = 0, oldoffset = 0, curcolumn = 0, vtableoffset = 0 '-000', shortbuf = , lock = 0x8049780, offset = -1, pad1 = 0x0, pad2 = 0x8049798, (gdb) n 9 c = fgetc(fp); (gdb) print *fp $2 = {flags = -72539000, IOreadptr = 0x40018001 "ug.5, 2005-n", '=' snip IOreadbase = 0x40018000 "Aug.5, 2005-n", '=' snip IOwritebase = 0x40018000 "Aug.5, 2005-n", '=' snip IOwriteptr = 0x40018000 "Aug.5, 2005-n", '=' snip IOwriteend = 0x40018000 "Aug.5, 2005-n", '=' snip IObufbase = 0x40018000 "Aug.5, 2005-n", '=' snip IOsavebase = 0x0, IObackupbase = 0x0, IOsaveend = 0x0, markers = 0x0, chain = 0x4014abe0, fileno = 5, blksize = 0, oldoffset = 0, curcolumn = 0, vtableoffset = 0 '-000', shortbuf = , lock = 0x8049780, offset = -1, pad1 = 0x0, pad2 = 0x8049798,

It's clear that IOreadptr points to the first (counting from zero) character of the file in this instance, but several of the other fields are identical to each other and start at the beginning of the file. There is nothing that seems to give the value of ftell at that point, even though I can certainly tell gdb to print ftell(fp).

So, how do I make better use of the various fields of *fp from inside gdb? -- Ignorantly, * Disclaimer: I am a guest and *not* a member of the MIT CSAIL. My actions and * comments do not reflect in any way on MIT. Also, I am nowhere near Boston.