Title here
Summary here
Time Formatting Parsing in Assembly Language
section .data
time_format db "2006-01-02T15:04:05-07:00", 0
time_str db "2012-11-01T22:08:41+00:00", 0
custom_format1 db "3:04PM", 0
custom_format2 db "Mon Jan _2 15:04:05 2006", 0
custom_format3 db "2006-01-02T15:04:05.999999-07:00", 0
custom_time db "8 41 PM", 0
custom_format4 db "3 04 PM", 0
format_str db "%d-%02d-%02dT%02d:%02d:%02d-00:00", 10, 0
section .text
global _start
_start:
; Get current time
mov eax, 13 ; sys_time syscall number
int 0x80
mov [current_time], eax
; Format current time (simplified)
mov eax, [current_time]
add eax, 946684800 ; Convert Unix time to years since 2000
mov ecx, 365*24*60*60
xor edx, edx
div ecx
add eax, 2000
push eax ; Year
; ... (similar calculations for month, day, hour, minute, second)
; Print formatted time
push dword [second]
push dword [minute]
push dword [hour]
push dword [day]
push dword [month]
push dword [year]
push format_str
call printf
add esp, 28
; Exit program
mov eax, 1 ; sys_exit syscall number
xor ebx, ebx ; Exit code 0
int 0x80
section .bss
current_time resq 1
year resd 1
month resd 1
day resd 1
hour resd 1
minute resd 1
second resd 1This Assembly Language example demonstrates a simplified version of time formatting. Assembly doesn’t have built-in libraries for complex time operations, so we’ve focused on the basic concept of getting the current time and formatting it.
Key points:
- We use the
sys_timesyscall to get the current Unix timestamp. - The time is then converted from Unix time (seconds since 1970) to components like year, month, day, etc. This involves some arithmetic operations.
- We use a format string similar to the C
printffunction to output the formatted time.
Note that this is a very basic implementation. Real-world assembly programs for time formatting would likely use system libraries or more complex algorithms for accurate time calculations, especially for handling time zones, leap years, etc.
To run this program, you would typically:
- Save it to a file (e.g.,
time_format.asm) - Assemble it:
nasm -f elf time_format.asm - Link it:
ld -m elf_i386 -o time_format time_format.o - Execute:
./time_format
This example provides a basic illustration of working with time in assembly, but it’s important to note that for complex time operations, higher-level languages or specialized libraries are typically more practical and accurate.