Forge

std.string

String manipulation for null-terminated C-style strings.

Functions

strlen

def strlen(s: ptr[char]) -> uint64

Return the length of a null-terminated string (excluding the null terminator).

from std.string import strlen

let len = strlen("Hello")   # 5

strcmp

def strcmp(a: ptr[char], b: ptr[char]) -> int32

Lexicographically compare two strings. Returns < 0, 0, or > 0.

from std.string import strcmp

if strcmp(a, b) == 0:
    puts("equal")

strncmp

def strncmp(a: ptr[char], b: ptr[char], n: uint64) -> int32

Compare at most n characters. Same return convention as strcmp.

strncmp("hello world", "hello there", 5)   # 0

strstr

def strstr(haystack: ptr[char], needle: ptr[char]) -> ptr[char]

Find the first occurrence of needle in haystack. Returns a pointer to the match, or null if not found.

let pos = strstr("needle in haystack", "needle")
# pos points at the start of "needle"

strchr

def strchr(s: ptr[char], c: int32) -> ptr[char]

Find the first occurrence of character c in s. Returns a pointer to the match, or null if not found. The character is passed as int32:

let ch = strchr("abc", 'b' as int32)

strcat

def strcat(dest: ptr[char], src: ptr[char]) -> ptr[char]

Append src to the end of dest (which must have room). Returns dest.

strncpy

def strncpy(dest: ptr[char], src: ptr[char], n: uint64) -> ptr[char]

Copy at most n characters from src to dest. Returns dest.

Implementation Notes

• All functions stop at the first null terminator
• No bounds checking beyond the null terminator — the caller must ensure destination buffers have room (especially for strcat/strncpy)
• Case-sensitive (ASCII ordering)

Example: Prefix Check

from std.string import strlen, strncmp
from std.io import puts

def starts_with(s: ptr[char], prefix: ptr[char]) -> bool:
    let len = strlen(prefix)
    return strncmp(s, prefix, len) == 0

pub def main() -> int32:
    if starts_with("help me", "help"):
        puts("Help requested\n")
    return 0

Target Support

All targets: pure Forge implementation, no syscalls needed.

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