C: add portable_basename.*

c-programming/strings/portable_basename.c

@@ -0,0 +1,258 @@
+/*
+ * portable_basename.c
+ *
+ * Author: Intel A80486DX2-66
+ * License: Unlicense
+ */
+
+#include "portable_basename.h"
+
+static char* correct_slashes(const char* path) {
+	char* new_path = strdup(path);
+	if (new_path == NULL)
+		return NULL;
+
+	char* ptr = new_path;
+	while (*ptr != '\0') {
+		if (*ptr == '\\')
+			*ptr = '/';
+		ptr++;
+	}
+
+	return new_path;
+}
+
+char* portable_basename(const char* raw_path) {
+	char* path = correct_slashes(raw_path);
+	if (path == NULL)
+		return NULL;
+
+	char* base = malloc(FILENAME_MAX * sizeof(char));
+	if (base == NULL) {
+		free(path);
+		return NULL;
+	}
+
+	size_t fname_len = strlen(path);
+
+	const char* last_slash = strrchr(path, '/');
+	if (last_slash != NULL)
+		fname_len = strlen(last_slash + 1);
+
+	memcpy(base, last_slash + 1, fname_len);
+	base[fname_len] = '\0';
+
+	return base;
+}
+
+#ifdef TEST
+# include <inttypes.h>
+# include <stdbool.h>
+# include <stdio.h>
+# include <time.h>
+
+// system identification
+# ifdef _WIN32
+#  define SYS_NT
+#  include <windows.h>
+# endif
+
+# if defined(__unix__) || defined(__APPLE__)
+#  define SYS_UNIX
+# endif
+
+// macros
+# if defined(SYS_UNIX) && !defined(CLOCK_MONOTONIC_RAW)
+#  define CLOCK_MONOTONIC_RAW CLOCK_MONOTONIC
+# endif
+
+// function prototypes
+long double clock_hr_microsec(void);
+# ifdef SYS_NT
+void WinAPI_perror(const char* s);
+# endif
+static void func_expect(const char* path, const char* expected_output,
+                        bool expect_to_succeed);
+
+long double clock_hr_microsec(void) {
+# ifdef SYS_NT
+	// TODO: FIXME: less accurate than Unix
+
+	LARGE_INTEGER counter;
+	if (!QueryPerformanceCounter(&counter)) {
+		WinAPI_perror("QueryPerformanceCounter");
+		exit(EXIT_FAILURE);
+	}
+	return (long double) (counter.QuadPart * 1000000ULL);
+# elif SYS_UNIX
+	struct timespec ts;
+	clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
+	return ((long double) (ts.tv_sec * 1000000000ULL + ts.tv_nsec)) / 1000.l;
+# else
+	return (long double) (clock() * 1000000ULL);
+# endif
+}
+
+// macros
+# ifdef SYS_NT
+#  define WinAPI_perror_COMMON_MACRO \
+      fprintf(stderr, "%s: %lu, %s", s, errorCode, errorString)
+
+// function implementations
+void WinAPI_perror(const char* s) {
+	DWORD errorCode = GetLastError();
+	LPSTR errorString = NULL;
+	FormatMessage(
+		FORMAT_MESSAGE_ALLOCATE_BUFFER |
+		FORMAT_MESSAGE_FROM_SYSTEM |
+		FORMAT_MESSAGE_IGNORE_INSERTS,
+		NULL,
+		errorCode,
+		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+		(LPSTR)&errorString,
+		0,
+		NULL
+	);
+
+	if (errorString == NULL) {
+		errorString = "???\n";
+		WinAPI_perror_COMMON_MACRO;
+	} else {
+		WinAPI_perror_COMMON_MACRO;
+		LocalFree(errorString);
+	}
+}
+# endif
+
+// macros
+# if defined(SYS_NT)
+LONGLONG QPF_frequency;
+#  define CLOCK_HR_DIFFTIME_MS(t2, t1)                                        \
+       ((long double) ((t2) - (t1))) / ((long double) QPF_frequency)
+# elif defined(SYS_UNIX)
+#  define CLOCK_HR_DIFFTIME_MS(t2, t1)                                        \
+       ((t2) - (t1))
+# else
+#  define CLOCK_HR_DIFFTIME_MS(t2, t1)                                        \
+       ((long double) ((t2) - (t1)) * 1000000.L) /                            \
+       ((long double) CLOCKS_PER_SEC)
+# endif
+
+// global variables
+uintmax_t tests_failed = 0;
+
+// function implementations
+static void func_expect(const char* path, const char* expected_output,
+                        bool expect_to_succeed) {
+	long double t1 = 0, t2 = 0;
+
+	t1 = clock_hr_microsec();
+	char* output = portable_basename(path);
+	t2 = clock_hr_microsec();
+	if (output == NULL) {
+		perror("portable_basename");
+		exit(EXIT_FAILURE);
+	}
+
+	const char* caption = expect_to_succeed ? "Expected output  "
+	                                        : "Unexpected output";
+	long double t = CLOCK_HR_DIFFTIME_MS(t2, t1);
+	printf("Input path       : '%s'\n"
+	       "%s: '%s'\n"
+	       "Actual output    : '%s'\n"
+	       "Time, clock_t    : %.3Lf microsec\n"
+	       "Test result      : ", path, caption, expected_output, output, t);
+	if ((bool) (strcmp(output, expected_output)) == expect_to_succeed) {
+		tests_failed++;
+		free(output);
+
+		puts("Failed!\n");
+		return;
+	}
+	puts("Passed\n");
+
+	free(output);
+	fflush(stdout);
+}
+
+// macros
+#define STRINGIZE(x) #x
+#define INT2STR(x) STRINGIZE(x)
+
+#define TIMES_TO_CALL 65535
+#include<unistd.h>
+int main(void) {
+# ifdef SYS_NT
+	// set console output code page to the native one
+	SetConsoleOutputCP(GetACP());
+
+	// get CPU frequency
+	LARGE_INTEGER freq;
+	if (!QueryPerformanceFrequency(&freq)) {
+		WinAPI_perror("QueryPerformanceFrequency");
+		return EXIT_FAILURE;
+	}
+
+	QPF_frequency = freq.QuadPart;
+# endif
+
+	// positive tests
+	func_expect("/", "", true);
+	func_expect("/usr/include/stdlib.h", "stdlib.h", true);
+	func_expect("C:\\Windows\\Fonts\\consola.ttf", "consola.ttf", true);
+	func_expect("\\..\\..\\directory\\.e.x.e.c.u.t.a.b.l.e.",
+	            ".e.x.e.c.u.t.a.b.l.e.", true);
+
+	// negative tests
+	func_expect("/a/.b.c.", "b.c", false);
+	func_expect("/a/.b.c.", ".b.c", false);
+	func_expect("/a/.b.c.", "b.c.", false);
+	func_expect("/a/.b.c.\\", ".b.c.", false);
+
+	printf("Failed tests: %" PRIuMAX "\n", tests_failed);
+
+	// timing test
+	puts("\nBenchmarking (" INT2STR(TIMES_TO_CALL) " calls):");
+	fflush(stdout);
+
+#define BENCHMARKING_STRING_SET \
+	"a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r\\s\\t\\u\\v\\w\\x\\y\\z\\.\\file", \
+	"/mnt/cdrom/usr/bin/include/library/test_files/test.h"
+
+	const char* string_set[] = {
+		BENCHMARKING_STRING_SET,
+		// HACK: try to prevent caching by using different pointers
+		BENCHMARKING_STRING_SET,
+		BENCHMARKING_STRING_SET,
+		BENCHMARKING_STRING_SET
+	};
+
+	const size_t string_set_len = sizeof(string_set) / sizeof(char*);
+
+	long double t_beginning = 0, t_end = 0;
+	long double t_total = 0.l;
+
+	for (uint_fast16_t i = 0; i < TIMES_TO_CALL; i++) {
+		const char* selected_string = string_set[i % string_set_len];
+
+		t_beginning = clock_hr_microsec();
+		char* output = portable_basename(selected_string);
+		t_end = clock_hr_microsec();
+
+		if (output == NULL) {
+			perror("portable_basename");
+			return EXIT_FAILURE;
+		}
+
+		free(output);
+
+		t_total += CLOCK_HR_DIFFTIME_MS(t_end, t_beginning);
+	}
+
+	printf("Total time: %.3Lf microsec, avg. %.3Lf microsec\n", t_total,
+	       t_total / ((long double) TIMES_TO_CALL));
+
+	return (tests_failed > 0 ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+#endif /* TEST */

c-programming/strings/portable_basename.h

@@ -0,0 +1,18 @@
+/*
+ * portable_basename.h
+ *
+ * Author: Intel A80486DX2-66
+ * License: Unlicense
+ */
+
+#ifndef _PORTABLE_BASENAME_H
+#define _PORTABLE_BASENAME_H
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static char* correct_slashes(const char* path);
+char* portable_basename(const char* raw_path);
+
+#endif /* _PORTABLE_BASENAME_H */