Beginning x64 Assembly Programming: From Novice to AVX Professional

© Jo Van Hoey 2019

J. Van HoeyBeginning x64 Assembly Programminghttps://doi.org/10.1007/978-1-4842-5076-1_31

31. Search for a Character

Jo Van Hoey¹ 

(1)

Hamme, Belgium

 

In this chapter, we will start using the control byte to help us find a specific character in a string.

Determining the Length of a String

In the first example, we will determine the length of a string by looking for a terminating 0.

Listing 31-1 shows the code.

; sse_string_length.asm

extern printf

section .data

;template            0123456789abcdef0123456789abcdef0123456789abcd  e

;template            1234567890123456789012345678901234567890123456  7

      string1 db    "The quick brown fox jumps over the lazy river.",0

      fmt1 db       "This is our string: %s ",10,0

      fmt2 db       "Our ...