program code build/program-x86: file format elf32-i386 Disassembly of section my_text: 080a9dfc : 80a9dfc: 55 push %ebp 80a9dfd: 89 e5 mov %esp,%ebp 80a9dff: 57 push %edi 80a9e00: 56 push %esi 80a9e01: 53 push %ebx 80a9e02: 83 ec 14 sub $0x14,%esp // 20 byte na lokalni promenne 80a9e05: c7 45 e0 00 00 00 00 movl $0x0,-0x20(%ebp) // vynuluj lokalni promennou na bp-0x20 80a9e0c: 8d 7d f3 lea -0xd(%ebp),%edi // ukazatel do lokaknich promennych 80a9e0f: 8b 75 0c mov 0xc(%ebp),%esi // parametr 2 80a9e12: 83 c6 30 add $0x30,%esi // pricti k nemu ASCII '0' 80a9e15: ba 01 00 00 00 mov $0x1,%edx // hodnota 1 80a9e1a: 8b 5d 08 mov 0x8(%ebp),%ebx // 1. parametr funkce 80a9e1d: 89 f9 mov %edi,%ecx // lokalni buffer 80a9e1f: b8 03 00 00 00 mov $0x3,%eax // syscall read 80a9e24: cd 80 int $0x80 // read(par1, ptr to local var, 1) 80a9e26: 83 f8 01 cmp $0x1,%eax // navratova hodnota je 1? 80a9e29: 74 0c je 80a9e37 // ano 80a9e2b: bb 01 00 00 00 mov $0x1,%ebx 80a9e30: b8 01 00 00 00 mov $0x1,%eax 80a9e35: cd 80 int $0x80 // ne exit(1) 80a9e37: 0f b6 45 f3 movzbl -0xd(%ebp),%eax // roztahnout na 32 bit 80a9e3b: 3c 2f cmp $0x2f,%al // je < nez ASCII '0' 80a9e3d: 7e 17 jle 80a9e56 // ano konec 80a9e3f: 0f be d0 movsbl %al,%edx 80a9e42: 39 f2 cmp %esi,%edx // Je >= par2 + '0' 80a9e44: 7d 10 jge 80a9e56 // ano konec 80a9e46: 8b 45 0c mov 0xc(%ebp),%eax // znova nacti param2 80a9e49: 0f af 45 e0 imul -0x20(%ebp),%eax // vynasob s nim ebp-0x20 80a9e4d: 8d 54 10 d0 lea -0x30(%eax,%edx,1),%edx // secti vysledek nactenym znakem - ASCII '0' 80a9e51: 89 55 e0 mov %edx,-0x20(%ebp) // uloz do lokalni promenne ebp-0x20 80a9e54: eb bf jmp 80a9e15 // opakuj 80a9e56: 8b 45 e0 mov -0x20(%ebp),%eax // vrat hodnotu lokalni promenne ebp-0x20 80a9e59: 83 c4 14 add $0x14,%esp 80a9e5c: 5b pop %ebx 80a9e5d: 5e pop %esi 80a9e5e: 5f pop %edi 80a9e5f: 5d pop %ebp 80a9e60: c3 ret 080a9e61 : 80a9e61: 55 push %ebp 80a9e62: 89 e5 mov %esp,%ebp 80a9e64: 57 push %edi 80a9e65: 56 push %esi 80a9e66: 53 push %ebx 80a9e67: 83 ec 20 sub $0x20,%esp // prostor pro lokalni promenne 80a9e6a: c6 45 f3 41 movb $0x41,-0xd(%ebp) // uloz ASCII 'A' na ebp-0xd 80a9e6e: c7 44 24 04 0a 00 00 movl $0xa,0x4(%esp) // uloz 10 na prvni pozici pod vrcholem zasobniku 80a9e75: 00 80a9e76: c7 04 24 00 00 00 00 movl $0x0,(%esp) // vynuluj vrchol zasobniku 80a9e7d: e8 7a ff ff ff call 80a9dfc // volej subroutine_fnc(0,10) 80a9e82: 89 c7 mov %eax,%edi // uloz vysledek 80a9e84: ba 80 01 00 00 mov $0x180,%edx 80a9e89: b9 42 02 00 00 mov $0x242,%ecx 80a9e8e: be 00 7f 0c 08 mov $0x80c7f00,%esi // napln ukazatel na "data" 80a9e93: 89 f3 mov %esi,%ebx 80a9e95: b8 05 00 00 00 mov $0x5,%eax // syscall open 80a9e9a: cd 80 int $0x80 // open("data", 0x242, 0x180) 80a9e9c: 89 45 dc mov %eax,-0x24(%ebp) // uloz vysledek do ebp-0x24 80a9e9f: 85 c0 test %eax,%eax // nastav priznaky 80a9ea1: 79 0e jns 80a9eb1 // znamenko neni nastaveno (>=0) 80a9ea3: b8 01 00 00 00 mov $0x1,%eax 80a9ea8: 89 c3 mov %eax,%ebx 80a9eaa: b8 01 00 00 00 mov $0x1,%eax // syscall exit 80a9eaf: cd 80 int $0x80 // exit(1) 80a9eb1: 89 7d e0 mov %edi,-0x20(%ebp) // vysledek subroutine_fnc do ebp-0x20 80a9eb4: 8d 75 f3 lea -0xd(%ebp),%esi // ebp-0xd je ukazatel na 'A' 80a9eb7: eb 22 jmp 80a9edb 80a9eb9: 8b 5d dc mov -0x24(%ebp),%ebx // vyzvedni vysledek open 80a9ebc: 89 f1 mov %esi,%ecx // ukazatel na 'A' 80a9ebe: ba 01 00 00 00 mov $0x1,%edx 80a9ec3: b8 04 00 00 00 mov $0x4,%eax // syscall write 80a9ec8: cd 80 int $0x80 // write(fd z open, "A", 1) 80a9eca: 85 c0 test %eax,%eax // test vysledku 80a9ecc: 79 09 jns 80a9ed7 80a9ece: 89 d3 mov %edx,%ebx // nastavene znamenko 80a9ed0: b8 01 00 00 00 mov $0x1,%eax 80a9ed5: cd 80 int $0x80 // exit(1) 80a9ed7: 83 6d e0 01 subl $0x1,-0x20(%ebp) // odecti 1 z ebp-0x20 80a9edb: 83 7d e0 00 cmpl $0x0,-0x20(%ebp) // bylo dosazeno 0 80a9edf: 75 d8 jne 80a9eb9 // ne => opakuj 80a9ee1: 8b 5d dc mov -0x24(%ebp),%ebx // fd z open 80a9ee4: b8 06 00 00 00 mov $0x6,%eax // syscall close 80a9ee9: cd 80 int $0x80 // close(fd z open) 80a9eeb: 85 c0 test %eax,%eax // test vysledku 80a9eed: 79 0e jns 80a9efd 80a9eef: b8 01 00 00 00 mov $0x1,%eax 80a9ef4: 89 c3 mov %eax,%ebx 80a9ef6: b8 01 00 00 00 mov $0x1,%eax 80a9efb: cd 80 int $0x80 // pro zaporny exit(1) 80a9efd: 89 f8 mov %edi,%eax // vrat uchovany vysledek // funkce subroutine_fnc 80a9eff: 83 c4 20 add $0x20,%esp 80a9f02: 5b pop %ebx 80a9f03: 5e pop %esi 80a9f04: 5f pop %edi 80a9f05: 5d pop %ebp 80a9f06: c3 ret program data build/program-x86: file format elf32-i386 Contents of section my_data: 80c7f00 64617461 00 data.