Project-owned freestanding string ABI primitives (strlen, strcmp, strchr, strstr, etc.). More...

#include <stddef.h>
#include <stdint.h>
#include "ra8_freestanding.h"

Include dependency graph for ra8_freestanding_str.c:

Functions
size_t	strlen (const char *s)
	Calculate string length.
size_t	strnlen (const char *s, size_t maxlen)
	Calculate bounded string length.
int	strcmp (const char s1, const char s2)
	Compare two null-terminated strings.
int	strncmp (const char s1, const char s2, size_t n)
	Compare two strings up to a specified length.
char *	strchr (const char *s, int c)
	Locate first occurrence of character in string.
char *	strrchr (const char *s, int c)
	Locate last occurrence of character in string.
char *	strstr (const char haystack, const char needle)
	Locate substring in string.
char *	strcpy (char dst, const char src)
	Copy string to destination buffer.
char *	strncpy (char dst, const char src, size_t n)
	Copy bounded string to destination buffer.

Detailed Description

Project-owned freestanding string ABI primitives (strlen, strcmp, strchr, strstr, etc.).

Tag: [Ring 0 / Foundation] {World: Dual}

Standard ISO C string primitives implemented directly for the bare-metal RA8 target firmware without libc or newlib dependencies. Deterministic, bounds-conscious, and heap-free.

Copyright: Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since: 0.1.0

Definition in file ra8_freestanding_str.c.

Function Documentation

◆ strchr()

char * strchr	(	const char *	s,
		int	c )

Locate first occurrence of character in string.

Scans s for the first instance of character c (including null).

Parameters

[in]	s	Null-terminated string to search.
[in]	c	Character value to locate.

Returns: Pointer to first occurrence in s, or nullptr if not found.

Return values

non-null	Pointer to first matching character in `s`.
nullptr	Character not found in `s`.

Precondition: s points to a valid null-terminated string.; s is readable.

Postcondition: String content is unmodified.; Returned pointer (if non-null) is within s.

Note: Freestanding runtime primitive; never allocates; reentrant and thread-safe when input string is not concurrently modified.

Since: 0.1.0

Definition at line 157 of file ra8_freestanding_str.c.

References memcpy().

Referenced by internal_args_attach_blank_sd(), internal_authority_of(), internal_config_apply_line(), internal_cookie_name_valid(), internal_has_separator(), internal_json_str(), internal_mdl_state_split_tabs(), internal_next_line(), internal_panel_split_kv(), internal_parse_kv_line(), internal_parse_panel(), internal_parse_xml_tag(), internal_pubid_byte(), internal_split_field(), mdl_extract_selector(), mdl_meta_parse(), mdl_url_host(), and mdl_url_path().

◆ strcmp()

int strcmp	(	const char *	s1,
		const char *	s2 )

Compare two null-terminated strings.

Compares s1 and s2 lexicographically as unsigned char values.

Parameters

[in]	s1	First null-terminated string.
[in]	s2	Second null-terminated string.

Returns: Difference between first differing characters, or 0 if identical.

Return values

0	Strings are identical up to null terminator.
<0	First non-matching character in `s1` is less than in `s2`.
>0	First non-matching character in `s1` is greater than in `s2`.

Precondition: Both s1 and s2 are valid null-terminated strings.; String buffers are readable.

Postcondition: Both input strings are unmodified.; Comparison semantics follow unsigned byte values.

Note: Freestanding runtime primitive; never allocates; reentrant and thread-safe when input strings are not concurrently modified.

Since: 0.1.0

Definition at line 93 of file ra8_freestanding_str.c.

Referenced by internal_add_manifest_image(), internal_agent_spec(), internal_already_have(), internal_apply_semantic_key(), internal_cache_find(), internal_cache_find(), internal_compile_images(), internal_compile_stylesheets(), internal_config_apply_pair(), internal_config_apply_string(), internal_config_apply_u32(), internal_config_parse_order(), internal_config_valid(), internal_demo_probe_fat(), internal_demo_probe_foreign(), internal_duplicate_name(), internal_epub_media_type_from_sniff(), internal_epub_media_type_from_suffix(), internal_epub_page_is_cover(), internal_extract_meta(), internal_extract_series_metadata(), internal_find_row(), internal_format(), internal_gov_find(), internal_hit_index_of(), internal_is_dot_segment(), internal_is_option_value(), internal_is_reserved_base(), internal_is_void(), internal_key_is(), internal_library_leaf(), internal_mdl_fetch_discard_stale_page(), internal_mdl_fetch_try_reuse(), internal_modem_answer_line(), internal_parse(), internal_parse(), internal_parse(), internal_parse_arguments(), internal_parse_verify_opt(), internal_parse_xml_semantics(), internal_redirect_host_ok(), internal_remove_stale_page_variants(), internal_resolve_one_leaf(), internal_resolve_removal_target(), internal_root_walk_step(), internal_snapshot_prior_metadata(), internal_sort_pages(), internal_split_output(), internal_split_output(), internal_split_output(), internal_split_path(), internal_stub_listdir(), internal_stub_open(), internal_stub_stat(), internal_take_flag(), internal_take_opt(), internal_tar_member(), internal_urlname_is_known_ext(), internal_validate_network_args(), internal_zip_member(), main(), mdl_extract_images(), mdl_format_from_str(), mdl_governor_peek(), mdl_robots_cache_consult(), mdl_search_filter_series_hits(), mdl_state_chapter_complete(), mdl_state_chapter_pages(), mdl_state_find_chapter(), mdl_storage_copy_atomic(), priv_book_is_block(), priv_fmt_try_portable_convert(), priv_fmt_try_portable_inspect(), priv_fmt_try_portable_verify(), priv_fs_posix_dir_next(), priv_fs_posix_root_alias_classify(), priv_mdl_export_path_join(), priv_mdl_export_prepare_cover(), priv_reflow_tok_classify(), and prof_load().

◆ strcpy()

char * strcpy	(	char *	dst,
		const char *	src )

Copy string to destination buffer.

Copies string src (including terminating null) to dst.

Parameters

[out]	dst	Destination buffer pointer.
[in]	src	Source null-terminated string pointer.

Returns: Original destination pointer dst.

Return values

dst	The destination pointer passed in `dst` is always returned.

Precondition: dst has sufficient capacity to hold src and terminating null.; dst and src do not overlap.

Postcondition: The copied string at dst matches src.; Source string is unmodified.

Note: Freestanding runtime primitive; never allocates; reentrant and thread-safe when strings are not concurrently modified.

Since: 0.1.0

Definition at line 261 of file ra8_freestanding_str.c.

◆ strlen()

size_t strlen ( const char * s )

Calculate string length.

Computes number of characters before terminating null byte.

Parameters

[in] s Null-terminated character string.

Returns: String length in characters.

Return values

length Number of characters before null terminator.

Precondition: s points to a valid null-terminated string.; s is readable.

Postcondition: String content is unmodified.; Never negative.

Note: Freestanding runtime primitive; never allocates; reentrant and thread-safe when input string is not concurrently modified.

Since: 0.1.0

Definition at line 42 of file ra8_freestanding_str.c.

Referenced by cb_host_output_open(), demo_file_ops(), demo_print(), demo_puts(), demo_read_verify(), demo_write_test_file(), elf_sym_addr(), epub_toc_entry_to_chapter(), er_draw_key_label(), internal_add_manifest_image(), internal_add_rule(), internal_agent_spec(), internal_attr_at(), internal_authority_of(), internal_build_export_metadata(), internal_build_tar(), internal_cache_copy(), internal_cache_encode_record(), internal_cbz_add_metadata(), internal_ci_contains(), internal_class_has_token(), internal_cli_ends_ci(), internal_config_set_str(), internal_config_trim(), internal_config_valid(), internal_cookie_field_is(), internal_copy_fits(), internal_cover_copy(), internal_decode_entity(), internal_demo_http_get(), internal_demo_log(), internal_demo_print(), internal_elem_at(), internal_emit_cstr(), internal_ends_ci(), internal_ends_with(), internal_ends_with_ci(), internal_entity(), internal_epub_render_meta(), internal_exfat_list_emit(), internal_extract_label(), internal_extract_meta(), internal_fat_dir_scan_sector(), internal_filter_prefix(), internal_find_attr_value(), internal_find_ci(), internal_handle_cdata(), internal_handle_raw_text(), internal_hex_decode(), internal_intern_span(), internal_is_reserved_base(), internal_json_str(), internal_keyword(), internal_library_act_on_node(), internal_log(), internal_make_name(), internal_mdl_stage_headers(), internal_mdl_state_append_gaps(), internal_mdl_state_parse_binary64(), internal_mdl_state_paths(), internal_panel_rstrip(), internal_panel_set_name(), internal_parent(), internal_parse_panel(), internal_parse_xml_tag(), internal_prepare_filter_chapters(), internal_rcs_print(), internal_resolve_config_path(), internal_resolve_descriptor_path(), internal_resolve_one_leaf(), internal_resolve_pack_path(), internal_resolve_path_rel(), internal_resolve_scheme_rel(), internal_scan_tags(), internal_split_output(), internal_split_output(), internal_split_output(), internal_split_path(), internal_split_path(), internal_stage_name(), internal_stderr_write(), internal_str_copy_trimmed(), internal_tag_is(), internal_tar_header(), internal_terminator(), internal_text(), internal_text(), internal_text(), internal_text(), internal_text(), internal_text(), internal_trim_ws(), internal_url_slug(), internal_urlname_last_path_marker(), internal_urlname_path_end(), internal_urlname_path_start(), internal_validate_mode_fields(), internal_xml_unescape(), mdl_hash_str(), mdl_meta_parse(), mdl_path_contained(), mdl_path_join(), mdl_search_build_url(), mdl_urlname_chapter_parse(), mdl_xml_escape(), mkbookimg_dest_name(), priv_alphabet_soup_split_path(), priv_emu_io_err_text(), priv_emu_io_file_text(), priv_emu_io_out_text(), priv_match_grad(), priv_mdl_epub_add_str(), priv_mdl_epub_str_cat(), priv_mdl_state_relative_path_valid(), priv_mkbookimg_diag(), priv_mkfontimg_diag(), priv_ota_json_u32(), priv_ra8_svgp_attr(), priv_ra8_svgp_find_ci(), priv_ra8_svgp_starts_ci(), priv_reflow_tok_decode_entity(), priv_reflow_tok_find_lit(), priv_reflow_tok_skip_past(), priv_reflow_tok_starts_with(), priv_rv_diag(), ra8_rabook_intern(), rabook_import_open(), sh_center_x(), sh_comic_center_x(), sh_decode_entity(), sh_ext_match(), sh_fit(), sh_sd_listdir_cb(), sh_titlebar(), sh_xhtml_is_block(), sh_xhtml_is_suppress(), and xml_span_equal().

◆ strncmp()

int strncmp	(	const char *	s1,
		const char *	s2,
		size_t	n )

Compare two strings up to a specified length.

Compares at most n characters of s1 and s2.

Parameters

[in]	s1	First string.
[in]	s2	Second string.
[in]	n	Maximum characters to compare.

Returns: Difference between first differing characters, or 0 if identical.

Return values

0	Strings match for first `n` characters or up to null terminator.
<0	First non-matching character in `s1` is less than in `s2`.
>0	First non-matching character in `s1` is greater than in `s2`.

Precondition: s1 and s2 are readable up to n bytes or null-terminated.; Both pointers are addressable.

Postcondition: Both input strings are unmodified.; Bounded by n characters.

Note: Freestanding runtime primitive; never allocates; reentrant and thread-safe when input strings are not concurrently modified.

Since: 0.1.0

Definition at line 124 of file ra8_freestanding_str.c.

Referenced by epub_toc_entry_to_chapter(), internal_add_manifest_image(), internal_args_try_control(), internal_args_try_display(), internal_args_try_input(), internal_args_try_mode(), internal_args_try_sd(), internal_args_try_sym(), internal_config_valid(), internal_filter_prefix(), internal_init_site_identity(), internal_is_reserved_base(), internal_load_argv_traces(), internal_mdl_http_begin(), internal_mdl_start_request_valid(), internal_mdl_start_valid(), internal_output_path(), internal_panel_apply_kv(), internal_validate_mode_fields(), internal_xml_unescape(), mdl_extract_resolve_url(), mdl_extract_selector(), mdl_path_contained(), mdl_search_build_url(), priv_mdl_app_storage_publish_site(), priv_reflow_tok_decode_entity(), sh_decode_entity(), sh_xhtml_is_block(), and sh_xhtml_is_suppress().

◆ strncpy()

char * strncpy	(	char *	dst,
		const char *	src,
		size_t	n )

Copy bounded string to destination buffer.

Copies at most n characters from src to dst, padding with null bytes if src is shorter than n.

Parameters

[out]	dst	Destination buffer pointer.
[in]	src	Source string pointer.
[in]	n	Maximum number of bytes to write.

Returns: Original destination pointer dst.

Return values

dst	The destination pointer passed in `dst` is always returned.

Precondition: dst points to at least n writable bytes.; dst and src do not overlap.

Postcondition: Exactly n bytes are written to dst.; Source string is unmodified.

Note: Freestanding runtime primitive; never allocates; reentrant and thread-safe when strings are not concurrently modified.

Since: 0.1.0

Definition at line 288 of file ra8_freestanding_str.c.

Referenced by sh_copy_str(), sh_sd_listdir_cb(), and sh_seed_baked().

◆ strnlen()

size_t strnlen	(	const char *	s,
		size_t	maxlen )

Calculate bounded string length.

Computes length of string s up to a maximum of maxlen.

Parameters

[in]	s	Character string to measure.
[in]	maxlen	Maximum characters to examine.

Returns: Length of string up to maxlen.

Return values

length Min of characters before null terminator and maxlen.

Precondition: s points to readable memory of at least maxlen bytes or null-terminated.; s is addressable.

Postcondition: String content is unmodified.; Return value is at most maxlen.

Note: Freestanding runtime primitive; never allocates; reentrant and thread-safe when input string is not concurrently modified.

Since: 0.1.0

Definition at line 65 of file ra8_freestanding_str.c.

Referenced by internal_add_rule(), internal_cursor_entry(), internal_demo_roundtrip(), internal_library_leaf(), internal_library_remove_root(), internal_mdl_copy_field(), internal_mdl_http_field_copy(), internal_mdl_http_field_valid(), internal_mdl_request_field_valid(), internal_mdl_start_request_valid(), internal_mdl_start_valid(), internal_meta_candidate_path(), internal_urlname_copy(), mdl_robots_cache_consult(), mdl_urlname_chapter_parse(), mdl_urlname_chapter_text_parse(), priv_mdl_export_prepare_cover(), priv_mdl_export_validate_source_url(), and priv_mdl_state_field_valid().

◆ strrchr()

char * strrchr	(	const char *	s,
		int	c )

Locate last occurrence of character in string.

Scans s for the last instance of character c (including null).

Parameters

[in]	s	Null-terminated string to search.
[in]	c	Character value to locate.

Returns: Pointer to last occurrence in s, or nullptr if not found.

Return values

non-null	Pointer to last matching character in `s`.
nullptr	Character not found in `s`.

Precondition: s points to a valid null-terminated string.; s is readable.

Postcondition: String content is unmodified.; Returned pointer (if non-null) is within s.

Note: Freestanding runtime primitive; never allocates; reentrant and thread-safe when input string is not concurrently modified.

Since: 0.1.0

Definition at line 190 of file ra8_freestanding_str.c.

References memcpy().

Referenced by internal_body_paths(), internal_epub_media_type_from_suffix(), internal_mdl_fetch_try_reuse(), internal_parent(), internal_publish_page_image(), internal_resolve_one_leaf(), internal_split_path(), internal_split_path(), priv_alphabet_soup_split_path(), and priv_mdl_export_jof().

◆ strstr()

char * strstr	(	const char *	haystack,
		const char *	needle )

Locate substring in string.

Finds the first occurrence of needle in haystack.

Parameters

[in]	haystack	Null-terminated string to search.
[in]	needle	Null-terminated substring to locate.

Returns: Pointer to beginning of substring in haystack, or nullptr if not found.

Return values

non-null	Pointer to substring occurrence in `haystack`.
nullptr	Substring not found in `haystack`.

Precondition: Both haystack and needle are valid null-terminated strings.; Both buffers are readable.

Postcondition: Both input strings are unmodified.; Returns haystack if needle is empty.

Note: Freestanding runtime primitive; never allocates; reentrant and thread-safe when input strings are not concurrently modified.

Since: 0.1.0

Definition at line 222 of file ra8_freestanding_str.c.

References memcpy().

Referenced by internal_args_attach_blank_sd(), internal_authority_of(), internal_class_has_token(), internal_contains_ok(), internal_decode_fail(), internal_json_str(), internal_mve_exec_one(), internal_parse_xml_tag(), internal_resolve_scheme_rel(), internal_robots_target(), internal_run_stop_banner(), internal_sniff_content_type(), internal_urlname_path_start(), mdl_meta_parse(), mdl_search_filter_series_hits(), mdl_url_host(), mdl_url_path(), priv_epub_xml_attr_contains(), and priv_ota_json_u32().

Functions

Detailed Description

Function Documentation

◆ strchr()

◆ strcmp()

◆ strcpy()

◆ strlen()

◆ strncmp()

◆ strncpy()

◆ strnlen()

◆ strrchr()

◆ strstr()