执行时，常用-q去掉copyright等无用信息：
gdb ./a.out -q
| Command | simple cmd | Effect |
| Starting and stopping | ||
| quit | q | Exit GDB |
| run | r | Run your program(give command line arguments here) |
| kill | k | stop your program |
| set args | before run, set running args | |
| BreakPoints | ||
| break sum | b sum | set breakpoint at entry to function sum |
| break *0x80483c3 | b *0x80483c3 | set breakpoint at address 0x80483c3 |
| delete 1 | d 1 | delete breakpoint 1 |
| delete | d | delete all breakpoint |
| Execution | ||
| stepi | si | execute one instruction |
| stepi 4 | si 4 | execute 4 instructions |
| nexti | ni | Like stepi, but process through function calls |
| continue | c | resume execution |
| finish | f | run until current function returns |
| Examining code | ||
| disas | Disassemble current function | |
| disas sum | Disassemble function sum | |
| disas 0x80483b7 | Disassemble function around address 0x80483b7 | |
| disas 0x80483b7 0x80483c7 | Disassemble code within specified address range | |
| print /x $eip | Print program counter in hex | |
| Examining data | ||
| print $eax | p $eax |
Print contents of %eax in decimal |
| print /x $eax |
Print contents of %eax in hex |
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| print /t $eax |
Print contents of %eax in binary |
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| print 0x100 |
Print decimal representation of 0x100 |
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print /x 555 |
Print hex representation of 555 |
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print /x ($ebp+8) |
Print contents of %ebp plus 8 in hex |
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print*(int*)0xbffff890 |
Printintegerataddress0xbffff890 |
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print *(int *) ($ebp+8) |
Print integer at address %ebp + 8 |
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x/2w 0xbffff890 |
Examine two (4-byte) words starting at address 0xbffff890 |
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x/20b sum |
Examine first 20 bytes of function sum |
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| Useful information | ||
| info frame |
Information about current stack frame |
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| info registers |
Values of all the registers |
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