C: categorize files, update .gitignore

c-programming/experiments/clock-malfunction-imitation.c

@@ -0,0 +1,188 @@
+/*
+ * clock-malfunction-imitation.c
+ *
+ * Author: Intel A80486DX2-66
+ * License: Creative Commons Zero 1.0 Universal
+ */
+
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+
+#define EXIT_IN 2U
+#define SECOND_PRECISION 1L
+#define TIME_BEFORE_ACCIDENT 2UL
+
+#define TEST_LABEL(s) { \
+	printf("Test: %s\n", s); \
+	fflush(stdout); \
+}
+
+#define CLOCK_FUN_BEGIN                                                       \
+	static unsigned ticks_before_accident = TIME_BEFORE_ACCIDENT;             \
+	time_t y;
+
+#define CLOCK_FUN_END                                                         \
+	if (x != NULL) {                                                          \
+		*x = y;                                                               \
+	}                                                                         \
+	return y;
+
+time_t clock_change_time(time_t* x);
+time_t clock_exponential_growth(time_t* x);
+time_t clock_hang(time_t* x);
+time_t clock_overflow(time_t* x);
+time_t clock_reverse(time_t* x);
+void time_flow_test(time_t (*time_function)(time_t*));
+
+time_t clock_change_time(time_t* x) {
+	CLOCK_FUN_BEGIN
+
+	time(&y);
+
+	if (ticks_before_accident == 0) {
+		y = 0;
+
+		size_t max = sizeof(time(NULL)) / sizeof(int);
+		printf("max of clock_change_time = %zu\n", max);
+		size_t intmax_plus_1 = (size_t) INT_MAX + 1;
+
+		for (size_t i = 0; i < max; i++)
+			y |= (rand() & INT_MAX) * intmax_plus_1;
+	} else
+		ticks_before_accident--;
+
+	CLOCK_FUN_END
+}
+
+time_t clock_exponential_growth(time_t* x) {
+	CLOCK_FUN_BEGIN
+
+	static time_t counter = 1;
+
+	time(&y);
+
+	if (ticks_before_accident == 0) {
+		y += counter++;
+		counter *= counter;
+	} else {
+		ticks_before_accident--;
+	}
+
+	CLOCK_FUN_END
+}
+
+time_t clock_hang(time_t* x) {
+	CLOCK_FUN_BEGIN
+
+	static time_t last_time;
+
+	if (ticks_before_accident == 0)
+		y = last_time;
+	else {
+		time(&y);
+		last_time = y;
+		ticks_before_accident--;
+	}
+
+	CLOCK_FUN_END
+}
+
+time_t clock_overflow(time_t* x) {
+	CLOCK_FUN_BEGIN
+
+	time(&y);
+
+	if (ticks_before_accident == 0)
+		y = LONG_MAX - y;
+	else
+		ticks_before_accident--;
+
+	CLOCK_FUN_END
+}
+
+time_t clock_reverse(time_t* x) {
+	CLOCK_FUN_BEGIN
+
+	static time_t counter = 1, old_time;
+
+	if (ticks_before_accident == 0) {
+		y = old_time - counter++;
+	} else {
+		time(&y);
+		old_time = y;
+		ticks_before_accident--;
+	}
+
+	CLOCK_FUN_END
+}
+
+void time_flow_test(time_t (*time_function)(time_t*)) {
+	time_t current_time, previous_time;
+	double time_diff;
+
+	// Get the current time
+	time(&current_time);
+	previous_time = current_time;
+	bool first_time_passed = false;
+	unsigned i = 0;
+
+	for (;;) {
+		// Get the current time
+		time_function(&current_time);
+
+		// Calculate the time difference in seconds
+		time_diff = difftime(current_time, previous_time);
+		if (!first_time_passed) {
+			time_diff = (double) SECOND_PRECISION;
+			first_time_passed = true;
+		}
+		printf("time difference: %f", time_diff);
+		fflush(stdout);
+
+		// Check if the time difference exceeds a threshold (e.g., 1 second)
+		if (time_diff != (double) SECOND_PRECISION) {
+			printf(" -> Abnormal time flow detected!");
+			fflush(stdout);
+			if (++i >= EXIT_IN) {
+				printf("\nAborting\n");
+				fflush(stdout);
+				break;
+			}
+		}
+		printf("\n");
+		fflush(stdout);
+
+		// Update the previous time
+		previous_time = current_time;
+
+		usleep(SECOND_PRECISION * 1000000L);
+
+		first_time_passed = true;
+	}
+
+	printf("\n");
+	fflush(stdout);
+}
+
+int main(void) {
+	TEST_LABEL("clock_change_time")
+	                                        time_flow_test(&clock_change_time);
+
+	TEST_LABEL("clock_exponential_growth")
+	                                 time_flow_test(&clock_exponential_growth);
+
+	TEST_LABEL("clock_hang")
+	                                               time_flow_test(&clock_hang);
+
+	TEST_LABEL("clock_overflow")
+	                                           time_flow_test(&clock_overflow);
+
+	TEST_LABEL("clock_reverse")
+	                                            time_flow_test(&clock_reverse);
+
+	return 0;
+}

c-programming/experiments/floatscan-experiment.c

@@ -0,0 +1,536 @@
+/*
+ * This was an experiment to learn about how libc turn floating point strings
+ * into actual values.
+ *
+ * Expects the floating point string to be in stdin.
+ *
+ * The new added code:
+ *     Author: Intel A80486DX2-66
+ *     License: Creative Commons Zero 1.0 Universal
+ * The original code is from musl libc: version 1.2.4, src/internal/floatscan.c
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <math.h>
+#include <float.h>
+#include <limits.h>
+#include <errno.h>
+#include <ctype.h>
+
+/* wrapping code --- beginning */
+#define shgetc(f) fgetc(f)
+#define shlim(...)
+#define shunget(...)
+
+#define FLOAT_TYPE 0
+#define DOUBLE_TYPE 1
+#define LONG_DOUBLE_TYPE 2
+/* wrapping code --- end */
+
+/* the original musl libc code --- beginning */
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+
+#define LD_B1B_DIG 2
+#define LD_B1B_MAX 9007199, 254740991
+#define KMAX 128
+
+#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
+
+#define LD_B1B_DIG 3
+#define LD_B1B_MAX 18, 446744073, 709551615
+#define KMAX 2048
+
+#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
+
+#define LD_B1B_DIG 4
+#define LD_B1B_MAX 10384593, 717069655, 257060992, 658440191
+#define KMAX 2048
+
+#else
+#error Unsupported long double representation
+#endif
+
+#define MASK (KMAX-1)
+
+static long long scanexp(FILE *f, int pok)
+{
+	int c;
+	int x;
+	long long y;
+	int neg = 0;
+	
+	c = shgetc(f);
+	if (c=='+' || c=='-') {
+		neg = (c=='-');
+		c = shgetc(f);
+		if (c-'0'>=10U && pok) shunget(f);
+	}
+	if (c-'0'>=10U) {
+		shunget(f);
+		return LLONG_MIN;
+	}
+	for (x=0; c-'0'<10U && x<INT_MAX/10; c = shgetc(f))
+		x = 10*x + c-'0';
+	for (y=x; c-'0'<10U && y<LLONG_MAX/100; c = shgetc(f))
+		y = 10*y + c-'0';
+	for (; c-'0'<10U; c = shgetc(f));
+	shunget(f);
+	return neg ? -y : y;
+}
+
+
+static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int pok)
+{
+	uint32_t x[KMAX];
+	static const uint32_t th[] = { LD_B1B_MAX };
+	int i, j, k, a, z;
+	long long lrp=0, dc=0;
+	long long e10=0;
+	int lnz = 0;
+	int gotdig = 0, gotrad = 0;
+	int rp;
+	int e2;
+	int emax = -emin-bits+3;
+	int denormal = 0;
+	long double y;
+	long double frac=0;
+	long double bias=0;
+	static const int p10s[] = { 10, 100, 1000, 10000,
+		100000, 1000000, 10000000, 100000000 };
+
+	j=0;
+	k=0;
+
+	/* Don't let leading zeros consume buffer space */
+	for (; c=='0'; c = shgetc(f)) gotdig=1;
+	if (c=='.') {
+		gotrad = 1;
+		for (c = shgetc(f); c=='0'; c = shgetc(f)) gotdig=1, lrp--;
+	}
+
+	x[0] = 0;
+	for (; c-'0'<10U || c=='.'; c = shgetc(f)) {
+		if (c == '.') {
+			if (gotrad) break;
+			gotrad = 1;
+			lrp = dc;
+		} else if (k < KMAX-3) {
+			dc++;
+			if (c!='0') lnz = dc;
+			if (j) x[k] = x[k]*10 + c-'0';
+			else x[k] = c-'0';
+			if (++j==9) {
+				k++;
+				j=0;
+			}
+			gotdig=1;
+		} else {
+			dc++;
+			if (c!='0') {
+				lnz = (KMAX-4)*9;
+				x[KMAX-4] |= 1;
+			}
+		}
+	}
+	if (!gotrad) lrp=dc;
+
+	if (gotdig && (c|32)=='e') {
+		e10 = scanexp(f, pok);
+		if (e10 == LLONG_MIN) {
+			if (pok) {
+				shunget(f);
+			} else {
+				shlim(f, 0);
+				return 0;
+			}
+			e10 = 0;
+		}
+		lrp += e10;
+	} else if (c>=0) {
+		shunget(f);
+	}
+	if (!gotdig) {
+		errno = EINVAL;
+		shlim(f, 0);
+		return 0;
+	}
+
+	/* Handle zero specially to avoid nasty special cases later */
+	if (!x[0]) return sign * 0.0;
+
+	/* Optimize small integers (w/no exponent) and over/under-flow */
+	if (lrp==dc && dc<10 && (bits>30 || x[0]>>bits==0))
+		return sign * (long double)x[0];
+	if (lrp > -emin/2) {
+		errno = ERANGE;
+		return sign * LDBL_MAX * LDBL_MAX;
+	}
+	if (lrp < emin-2*LDBL_MANT_DIG) {
+		errno = ERANGE;
+		return sign * LDBL_MIN * LDBL_MIN;
+	}
+
+	/* Align incomplete final B1B digit */
+	if (j) {
+		for (; j<9; j++) x[k]*=10;
+		k++;
+		j=0;
+	}
+
+	a = 0;
+	z = k;
+	e2 = 0;
+	rp = lrp;
+
+	/* Optimize small to mid-size integers (even in exp. notation) */
+	if (lnz<9 && lnz<=rp && rp < 18) {
+		if (rp == 9) return sign * (long double)x[0];
+		if (rp < 9) return sign * (long double)x[0] / p10s[8-rp];
+		int bitlim = bits-3*(int)(rp-9);
+		if (bitlim>30 || x[0]>>bitlim==0)
+			return sign * (long double)x[0] * p10s[rp-10];
+	}
+
+	/* Drop trailing zeros */
+	for (; !x[z-1]; z--);
+
+	/* Align radix point to B1B digit boundary */
+	if (rp % 9) {
+		int rpm9 = rp>=0 ? rp%9 : rp%9+9;
+		int p10 = p10s[8-rpm9];
+		uint32_t carry = 0;
+		for (k=a; k!=z; k++) {
+			uint32_t tmp = x[k] % p10;
+			x[k] = x[k]/p10 + carry;
+			carry = 1000000000/p10 * tmp;
+			if (k==a && !x[k]) {
+				a = (a+1 & MASK);
+				rp -= 9;
+			}
+		}
+		if (carry) x[z++] = carry;
+		rp += 9-rpm9;
+	}
+
+	/* Upscale until desired number of bits are left of radix point */
+	while (rp < 9*LD_B1B_DIG || (rp == 9*LD_B1B_DIG && x[a]<th[0])) {
+		uint32_t carry = 0;
+		e2 -= 29;
+		for (k=(z-1 & MASK); ; k=(k-1 & MASK)) {
+			uint64_t tmp = ((uint64_t)x[k] << 29) + carry;
+			if (tmp > 1000000000) {
+				carry = tmp / 1000000000;
+				x[k] = tmp % 1000000000;
+			} else {
+				carry = 0;
+				x[k] = tmp;
+			}
+			if (k==(z-1 & MASK) && k!=a && !x[k]) z = k;
+			if (k==a) break;
+		}
+		if (carry) {
+			rp += 9;
+			a = (a-1 & MASK);
+			if (a == z) {
+				z = (z-1 & MASK);
+				x[z-1 & MASK] |= x[z];
+			}
+			x[a] = carry;
+		}
+	}
+
+	/* Downscale until exactly number of bits are left of radix point */
+	for (;;) {
+		uint32_t carry = 0;
+		int sh = 1;
+		for (i=0; i<LD_B1B_DIG; i++) {
+			k = (a+i & MASK);
+			if (k == z || x[k] < th[i]) {
+				i=LD_B1B_DIG;
+				break;
+			}
+			if (x[a+i & MASK] > th[i]) break;
+		}
+		if (i==LD_B1B_DIG && rp==9*LD_B1B_DIG) break;
+		/* FIXME: find a way to compute optimal sh */
+		if (rp > 9+9*LD_B1B_DIG) sh = 9;
+		e2 += sh;
+		for (k=a; k!=z; k=(k+1 & MASK)) {
+			uint32_t tmp = x[k] & (1<<sh)-1;
+			x[k] = (x[k]>>sh) + carry;
+			carry = (1000000000>>sh) * tmp;
+			if (k==a && !x[k]) {
+				a = (a+1 & MASK);
+				i--;
+				rp -= 9;
+			}
+		}
+		if (carry) {
+			if ((z+1 & MASK) != a) {
+				x[z] = carry;
+				z = (z+1 & MASK);
+			} else x[z-1 & MASK] |= 1;
+		}
+	}
+
+	/* Assemble desired bits into floating point variable */
+	for (y=i=0; i<LD_B1B_DIG; i++) {
+		if ((a+i & MASK)==z) x[(z=(z+1 & MASK))-1] = 0;
+		y = 1000000000.0L * y + x[a+i & MASK];
+	}
+
+	y *= sign;
+
+	/* Limit precision for denormal results */
+	if (bits > LDBL_MANT_DIG+e2-emin) {
+		bits = LDBL_MANT_DIG+e2-emin;
+		if (bits<0) bits=0;
+		denormal = 1;
+	}
+
+	/* Calculate bias term to force rounding, move out lower bits */
+	if (bits < LDBL_MANT_DIG) {
+		bias = copysignl(scalbn(1, 2*LDBL_MANT_DIG-bits-1), y);
+		frac = fmodl(y, scalbn(1, LDBL_MANT_DIG-bits));
+		y -= frac;
+		y += bias;
+	}
+
+	/* Process tail of decimal input so it can affect rounding */
+	if ((a+i & MASK) != z) {
+		uint32_t t = x[a+i & MASK];
+		if (t < 500000000 && (t || (a+i+1 & MASK) != z))
+			frac += 0.25*sign;
+		else if (t > 500000000)
+			frac += 0.75*sign;
+		else if (t == 500000000) {
+			if ((a+i+1 & MASK) == z)
+				frac += 0.5*sign;
+			else
+				frac += 0.75*sign;
+		}
+		if (LDBL_MANT_DIG-bits >= 2 && !fmodl(frac, 1))
+			frac++;
+	}
+
+	y += frac;
+	y -= bias;
+
+	if ((e2+LDBL_MANT_DIG & INT_MAX) > emax-5) {
+		if (fabsl(y) >= 2/LDBL_EPSILON) {
+			if (denormal && bits==LDBL_MANT_DIG+e2-emin)
+				denormal = 0;
+			y *= 0.5;
+			e2++;
+		}
+		if (e2+LDBL_MANT_DIG>emax || (denormal && frac))
+			errno = ERANGE;
+	}
+
+	return scalbnl(y, e2);
+}
+
+static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
+{
+	uint32_t x = 0;
+	long double y = 0;
+	long double scale = 1;
+	long double bias = 0;
+	int gottail = 0, gotrad = 0, gotdig = 0;
+	long long rp = 0;
+	long long dc = 0;
+	long long e2 = 0;
+	int d;
+	int c;
+
+	c = shgetc(f);
+
+	/* Skip leading zeros */
+	for (; c=='0'; c = shgetc(f)) gotdig = 1;
+
+	if (c=='.') {
+		gotrad = 1;
+		c = shgetc(f);
+		/* Count zeros after the radix point before significand */
+		for (rp=0; c=='0'; c = shgetc(f), rp--) gotdig = 1;
+	}
+
+	for (; c-'0'<10U || (c|32)-'a'<6U || c=='.'; c = shgetc(f)) {
+		if (c=='.') {
+			if (gotrad) break;
+			rp = dc;
+			gotrad = 1;
+		} else {
+			gotdig = 1;
+			if (c > '9') d = (c|32)+10-'a';
+			else d = c-'0';
+			if (dc<8) {
+				x = x*16 + d;
+			} else if (dc < LDBL_MANT_DIG/4+1) {
+				y += d*(scale/=16);
+			} else if (d && !gottail) {
+				y += 0.5*scale;
+				gottail = 1;
+			}
+			dc++;
+		}
+	}
+	if (!gotdig) {
+		shunget(f);
+		if (pok) {
+			shunget(f);
+			if (gotrad) shunget(f);
+		} else {
+			shlim(f, 0);
+		}
+		return sign * 0.0;
+	}
+	if (!gotrad) rp = dc;
+	while (dc<8) x *= 16, dc++;
+	if ((c|32)=='p') {
+		e2 = scanexp(f, pok);
+		if (e2 == LLONG_MIN) {
+			if (pok) {
+				shunget(f);
+			} else {
+				shlim(f, 0);
+				return 0;
+			}
+			e2 = 0;
+		}
+	} else {
+		shunget(f);
+	}
+	e2 += 4*rp - 32;
+
+	if (!x) return sign * 0.0;
+	if (e2 > -emin) {
+		errno = ERANGE;
+		return sign * LDBL_MAX * LDBL_MAX;
+	}
+	if (e2 < emin-2*LDBL_MANT_DIG) {
+		errno = ERANGE;
+		return sign * LDBL_MIN * LDBL_MIN;
+	}
+
+	while (x < 0x80000000) {
+		if (y>=0.5) {
+			x += x + 1;
+			y += y - 1;
+		} else {
+			x += x;
+			y += y;
+		}
+		e2--;
+	}
+
+	if (bits > 32+e2-emin) {
+		bits = 32+e2-emin;
+		if (bits<0) bits=0;
+	}
+
+	if (bits < LDBL_MANT_DIG)
+		bias = copysignl(scalbn(1, 32+LDBL_MANT_DIG-bits-1), sign);
+
+	if (bits<32 && y && !(x&1)) x++, y=0;
+
+	y = bias + sign*(long double)x + sign*y;
+	y -= bias;
+
+	if (!y) errno = ERANGE;
+
+	return scalbnl(y, e2);
+}
+
+long double __floatscan(FILE *f, int prec, int pok)
+{
+	int sign = 1;
+	size_t i;
+	int bits;
+	int emin;
+	int c;
+
+	switch (prec) {
+	case 0:
+		bits = FLT_MANT_DIG;
+		emin = FLT_MIN_EXP-bits;
+		break;
+	case 1:
+		bits = DBL_MANT_DIG;
+		emin = DBL_MIN_EXP-bits;
+		break;
+	case 2:
+		bits = LDBL_MANT_DIG;
+		emin = LDBL_MIN_EXP-bits;
+		break;
+	default:
+		return 0;
+	}
+
+	while (isspace((c=shgetc(f))));
+
+	if (c=='+' || c=='-') {
+		sign -= 2*(c=='-');
+		c = shgetc(f);
+	}
+
+	for (i=0; i<8 && (c|32)=="infinity"[i]; i++)
+		if (i<7) c = shgetc(f);
+	if (i==3 || i==8 || (i>3 && pok)) {
+		if (i!=8) {
+			shunget(f);
+			if (pok) for (; i>3; i--) shunget(f);
+		}
+		return sign * INFINITY;
+	}
+	if (!i) for (i=0; i<3 && (c|32)=="nan"[i]; i++)
+		if (i<2) c = shgetc(f);
+	if (i==3) {
+		if (shgetc(f) != '(') {
+			shunget(f);
+			return NAN;
+		}
+		for (i=1; ; i++) {
+			c = shgetc(f);
+			if (c-'0'<10U || c-'A'<26U || c-'a'<26U || c=='_')
+				continue;
+			if (c==')') return NAN;
+			shunget(f);
+			if (!pok) {
+				errno = EINVAL;
+				shlim(f, 0);
+				return 0;
+			}
+			while (i--) shunget(f);
+			return NAN;
+		}
+		return NAN;
+	}
+
+	if (i) {
+		shunget(f);
+		errno = EINVAL;
+		shlim(f, 0);
+		return 0;
+	}
+
+	if (c=='0') {
+		c = shgetc(f);
+		if ((c|32) == 'x')
+			return hexfloat(f, bits, emin, sign, pok);
+		shunget(f);
+		c = '0';
+	}
+
+	return decfloat(f, c, bits, emin, sign, pok);
+}
+/* the original musl libc code --- end */
+
+/* test code --- beginning */
+int main(void) {
+	printf("LD_B1B_DIG = %d\n", LD_B1B_DIG);
+	printf("%La\n", __floatscan(stdin, LONG_DOUBLE_TYPE, 1));
+	return 0;
+}
+/* test code --- end */

c-programming/experiments/reverse-ramdisk.c

@@ -0,0 +1,396 @@
+/*
+ * reverse-ramdisk.c
+ *
+ * C programming idea: Handling temporary files like memory allocations
+ * (allocating -> creating empty file, using -> locking for R/W,
+ * freeing -> deleting).
+ *
+ * 20% AI, 80% human (the code is tested and reviewed)
+ *
+ * Warning: The current result is quick and dirty. Not for educational or
+ * production purposes.
+ *
+ * GCC/Clang/TCC: Compile with -DTEST to set macro TEST as defined, with
+ * -DDEBUG to enable debug mode
+ *
+ * To-Do: Test: Fix the bug with invalid next size to reallocate
+ * To-Do: Test: Automate the test verification
+ *
+ * Author: Intel A80486DX2-66
+ * License: Creative Commons Zero 1.0 Universal
+ */
+
+#include <errno.h>
+#include <inttypes.h>
+#include <math.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if _POSIX_VERSION >= 200112L
+# include <fcntl.h>
+# include <unistd.h>
+# define IS_POSIX 1
+#else
+# define IS_POSIX 0
+#endif
+
+#ifdef DEBUG
+# define LINE_FAIL(x) printf("failed on line %d\n", __LINE__ + x)
+#else
+# define LINE_FAIL(x)
+#endif
+
+#if defined(DEBUG) || defined(TEST)
+# define DBG_PRINT(...) do { \
+	printf(__VA_ARGS__); \
+	fflush(stdout); \
+} while (0)
+#else
+# define DBG_PRINT(...)
+#endif
+
+#define RETREAT(s) do { \
+	perror(s); \
+	exit(EXIT_FAILURE); \
+} while (0)
+
+typedef struct {
+	bool locked;
+	int ID;
+	char* file_path;
+#if IS_POSIX
+	int file;
+#else
+	FILE* file;
+#endif
+} TempFile;
+
+TempFile* temp_files = NULL;
+size_t num_temp_files = 0;
+
+int tf_alloc(size_t n, size_t type_size);
+int tf_free(int ID);
+int tf_write(int ID, size_t offset, void* src, size_t data_size);
+int tf_read(int ID, size_t offset, void* dest, size_t data_size);
+
+int tf_alloc(size_t n, size_t type_size) {
+	DBG_PRINT("tf_alloc(%zu, %zu)\n", n, type_size);
+
+	// Create an empty file
+	size_t len_digit;
+	if (num_temp_files == 0)
+		len_digit = 1;
+	else
+		len_digit = (size_t) floor(log10((double) num_temp_files)) + 1;
+	size_t file_path_len = len_digit + strlen("tf_.tmp");
+	char* file_path = malloc((file_path_len + 1) * sizeof(char));
+	if (file_path == NULL) {
+		LINE_FAIL(-2);
+		return -1;
+	}
+	int res = snprintf(file_path, file_path_len + 1, "tf_%" PRIuMAX ".tmp",
+		(uintmax_t) num_temp_files);
+	if ((size_t) res != file_path_len) {
+		LINE_FAIL(-2);
+		return -1;
+	}
+
+#if IS_POSIX
+	int file = open(file_path, O_RDWR | O_CREAT);
+	if (file == -1) {
+#else
+	FILE* file = fopen(file_path, "w+b");
+	if (file == NULL) {
+#endif
+		LINE_FAIL(-2);
+		return -1;
+	}
+
+	// Allocate memory for the TempFile struct
+	TempFile* temp_file = malloc(sizeof(TempFile));
+	if (temp_file == NULL) {
+		LINE_FAIL(-2);
+		return -1;
+	}
+
+	// Assign the ID, file path, file handler
+	temp_file->locked = false;
+	temp_file->ID = num_temp_files;
+	temp_file->file_path = strdup(file_path);
+	temp_file->file = file;
+
+	// Allocate/reallocate memory for the temp_files structure
+	if (temp_files == NULL)
+		temp_files = malloc(sizeof(TempFile));
+	else
+		temp_files = realloc(temp_files, num_temp_files * sizeof(TempFile));
+	if (temp_files == NULL) {
+		LINE_FAIL(-2);
+		return -1;
+	}
+
+	// Add the temp file to the array
+	temp_files[num_temp_files++] = *temp_file;
+
+	return temp_file->ID;
+}
+
+int tf_free(int ID) {
+	DBG_PRINT("tf_free(%d)\n", ID);
+
+	size_t index = (size_t) ID;
+
+	if (temp_files[index].locked) {
+		errno = EBUSY;
+		return -1;
+	}
+	temp_files[index].locked = true;
+
+#if IS_POSIX
+	close(temp_files[index].file);
+#else
+	fclose(temp_files[index].file);
+#endif
+
+	// Delete the file
+	if (remove(temp_files[index].file_path) != 0) {
+		LINE_FAIL(-1);
+		return -1;
+	}
+
+	free(temp_files[index].file_path);
+
+	// Shift the remaining temp files in the array
+	for (size_t i = index; i < num_temp_files - 1; i++)
+		temp_files[i] = temp_files[i + 1];
+
+	// Reallocate memory for the temp_files array
+	if (--num_temp_files > 0) {
+		DBG_PRINT("num_temp_files = %zu\n", num_temp_files);
+		if ((temp_files = realloc(temp_files, num_temp_files
+			* sizeof(TempFile))) == NULL) {
+			LINE_FAIL(-2);
+			return -1;
+		}
+	}
+
+	temp_files[index].locked = false;
+
+	return 0;
+}
+
+int tf_write(int ID, size_t offset, void* src, size_t data_size) {
+	DBG_PRINT("tf_write(%d, %zu, %p, %zu)\n", ID, offset, src, data_size);
+
+	size_t index = (size_t) ID;
+
+	if (temp_files[index].locked) {
+		errno = EBUSY;
+		return -1;
+	}
+	temp_files[index].locked = true;
+
+#if IS_POSIX
+	// Check file handler for -1
+	int file = temp_files[index].file;
+	if (file == -1)
+#else
+	// Check file handler for NULL
+	FILE* file = temp_files[index].file;
+	if (file == NULL)
+#endif
+		return -1;
+
+	// Set the position
+#if IS_POSIX
+	if (lseek(file, offset, SEEK_SET) == -1) {
+#else
+	if (fseek(file, offset, SEEK_SET) == -1) {
+#endif
+		LINE_FAIL(-1);
+		return -1;
+	}
+
+	// Write the data to the file
+#if IS_POSIX
+	ssize_t
+#else
+	size_t
+#endif
+		bytes_written =
+#if IS_POSIX
+			write(file, src, data_size);
+#else
+			fwrite(src, 1, data_size, file);
+#endif
+
+	if (
+#if IS_POSIX
+		(size_t)
+#endif
+		bytes_written != data_size) {
+		errno = EIO;
+		return -1;
+	}
+
+#if IS_POSIX
+	if (fsync(file) == -1) {
+		LINE_FAIL(-1);
+		return -1;
+	}
+#else
+	fflush(file);
+#endif
+
+	temp_files[index].locked = false;
+
+	return 0;
+}
+
+int tf_read(int ID, size_t offset, void* dest, size_t data_size) {
+	DBG_PRINT("tf_read(%d, %zu, %p, %zu)\n", ID, offset, dest, data_size);
+
+	size_t index = (size_t) ID;
+
+	if (temp_files[index].locked) {
+		errno = EBUSY;
+		return -1;
+	}
+	temp_files[index].locked = true;
+
+#if IS_POSIX
+	int file = temp_files[index].file;
+	if (file == -1)
+#else
+	FILE* file = temp_files[index].file;
+	if (file == NULL)
+#endif
+		return -1;
+
+	// Read the data from the file
+	void* src = malloc(data_size);
+	if (src == NULL) {
+#if IS_POSIX
+		close(file);
+#else
+		fclose(file);
+#endif
+		LINE_FAIL(-7);
+		return -1;
+	}
+
+	memset(src, 0, data_size); // clear destination
+	// Set the position
+#if IS_POSIX
+	if (lseek(file, offset, SEEK_SET) == -1) {
+#else
+	if (fseek(file, offset, SEEK_SET) == -1) {
+#endif
+		LINE_FAIL(-1);
+		return -1;
+	}
+
+	// read bytes
+#if IS_POSIX
+	ssize_t bytes_read = read(file, src, data_size);
+#else
+	size_t bytes_read = fread(src, 1, data_size, file);
+#endif
+	memcpy(dest, src, data_size);
+
+	free(src); // Free the allocated memory
+
+	if (
+#if IS_POSIX
+		(size_t)
+#endif
+		bytes_read != data_size) {
+		errno = EIO;
+		return -1;
+	}
+
+#ifdef DEBUG
+	printf("Read: ID = %d, src = %p, size = %zu -> '",
+		ID, dest, data_size);
+	for (size_t i = 0; i < data_size; i++)
+		printf("0x%02" PRIX8 "%c", *((uint8_t*)((uint8_t*)dest + i)),
+			i == (data_size - 1) ? '\'' : ' ');
+	printf("\n");
+	fflush(stdout);
+#endif
+
+	temp_files[index].locked = false;
+
+	return 0;
+}
+
+#ifdef TEST
+int main(void) {
+	DBG_PRINT("started\n");
+
+#define ARRAY_1_LEN 4
+#define ARRAY_2_LEN 16
+
+	int ID_1 = tf_alloc(ARRAY_1_LEN, sizeof(int));
+	int ID_2 = tf_alloc(ARRAY_2_LEN, sizeof(uint16_t));
+	if (ID_1 == -1 || ID_2 == -1)
+		RETREAT("tf_alloc");
+	DBG_PRINT("allocated memory\n");
+
+	int test_data_1[ARRAY_1_LEN] = {123, 456, 789, -123};
+	DBG_PRINT("initialized array 1\n");
+
+	uint16_t test_data_2[ARRAY_2_LEN];
+	for (size_t i = 0; i < ARRAY_2_LEN; i++)
+		test_data_2[i] = 1 << i;
+	DBG_PRINT("initialized array 2\n");
+
+	for (size_t i = 0; i < ARRAY_1_LEN; i++)
+		if (tf_write(ID_1, i * sizeof(int), &test_data_1[i], sizeof(int)) == -1)
+			RETREAT("tf_write");
+	DBG_PRINT("wrote array 1\n");
+
+	for (size_t i = 0; i < ARRAY_2_LEN; i++)
+		if (tf_write(ID_2, i * sizeof(uint16_t), &test_data_2[i],
+			sizeof(uint16_t)) == -1)
+			RETREAT("tf_write");
+	DBG_PRINT("wrote array 2\n");
+
+	// round-trip
+	test_data_1[0] = 111;
+	test_data_1[1] = 222;
+	test_data_1[2] = 333;
+	test_data_1[3] = 444;
+	DBG_PRINT("filled array 1 with garbage\n");
+
+	for (size_t i = 0; i < 16; i++)
+		test_data_2[i] ^= 1;
+	DBG_PRINT("filled array 2 with garbage\n");
+
+	for (size_t i = 0; i < ARRAY_1_LEN; i++)
+		if (tf_read(ID_1, i * sizeof(int), &test_data_1[i], sizeof(int)) == -1)
+			RETREAT("tf_read");
+	DBG_PRINT("restored array 1\n");
+
+	for (size_t i = 0; i < ARRAY_2_LEN; i++)
+		if (tf_read(ID_2, i * sizeof(uint16_t), &test_data_2[i],
+			sizeof(uint16_t)) == -1)
+			RETREAT("tf_read");
+	DBG_PRINT("restored array 2\n");
+
+	DBG_PRINT("Values (1): ");
+	for (size_t i = 0; i < ARRAY_1_LEN; i++)
+		DBG_PRINT("%d%c", test_data_1[i], i == (ARRAY_1_LEN - 1) ? '\n' : ' ');
+	DBG_PRINT("Values (2): ");
+	for (size_t i = 0; i < ARRAY_2_LEN; i++)
+		DBG_PRINT("%d%c", test_data_2[i], i == (ARRAY_2_LEN - 1) ? '\n' : ' ');
+
+	tf_free(ID_1);
+	tf_free(ID_2);
+	DBG_PRINT("freed both files\n");
+
+	return 0;
+}
+#endif