Give install instructions.

It has been solved!!!

.gitlab-ci.yml

@@ -4,7 +4,7 @@ build:
     stage: build
     # Install dependencies
     before_script:
-        - apt update && apt -y install cmake libgmp-dev
+        - apt update && apt -y install cmake libgmp-dev libgomp1
     # Build the project
     script:
         - cd build/

CHANGELOG

@@ -27,3 +27,12 @@ Change Log
 	- Allow user to choose base in which the prime numbers are printed.
 	- Give option for primes to be saved to a file upon exit.
 	- Free memory and leave instead of emergency exit.
+- v0.7: Data Saving
+	- Allow user to save found primes to be loaded later.
+	- User can save and read primes in raw output.
+- v1.0: Parallelization
+	- Now completely parallelized.
+	- Cleaned up/organized the code-base
+	- Exporting files uses less memory
+	- Allow searching for the nth prime number
+	- Clearing some memory leaks

CMakeLists.txt

@@ -1,3 +1,19 @@
+# Copyright (C) 2017  Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+# Author: Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 cmake_minimum_required(VERSION 2.6)
 project(Indivisible)
 
@@ -6,34 +22,41 @@ cmake_policy(SET CMP0012 OLD)
 set(TARGET_NAME indivisible)
 
 if(NOT CMAKE_BUILD_TYPE)
-	set(CMAKE_BUILD_TYPE Debug)
+	set(CMAKE_BUILD_TYPE "debug")
 endif()
+string(TOLOWER ${CMAKE_BUILD_TYPE} CMAKE_BUILD_TYPE)
+message(STATUS "Build type: ${CMAKE_BUILD_TYPE}")
 
 set(CMAKE_MODULE_PATH
 	${CMAKE_MODULE_PATH}
 	${CMAKE_SOURCE_DIR}/cmake/)
 
 find_package(GMP REQUIRED)
+find_package(OpenMP REQUIRED)
 
 include_directories(
 	${GMP_INCLUDE_DIR})
 
 set(SRCS
 	src/main.c
+	src/files.c
 	src/list.c)
 
 # Define the C flags.
-set(CMAKE_C_FLAGS "-std=gnu99 -Wall -Wextra -Werror -Wfatal-errors -Wmissing-declarations -pedantic-errors")
+set(CMAKE_C_FLAGS "-std=gnu99 ${OpenMP_C_FLAGS} -Wall -Wextra -Werror -Wfatal-errors -Wmissing-declarations -pedantic-errors")
 set(CMAKE_C_FLAGS_DEBUG "-g -O0")
 set(CMAKE_C_FLAGS_RELEASE "-O3")
 set(CMAKE_C_FLAGS_RELWITHDEBINFO "-g -O3")
 set(CMAKE_C_FLAGS_MINSIZEREL "-Os")
 
-if(NOT CMAKE_BUILD_TYPE MATCHES Debug AND NOT CMAKE_BUILD_TYPE MATCHES RelWithDebInfo)
-	add_definitions(-DNDEBUG)
+if(NOT CMAKE_BUILD_TYPE MATCHES "debug" AND NOT CMAKE_BUILD_TYPE MATCHES "relwithdebinfo")
+	add_definitions("-DNDEBUG")
 endif()
 
 add_executable(${TARGET_NAME} ${SRCS})
 
 target_link_libraries(${TARGET_NAME}
 	${GMP_LIBRARY})
+
+install(TARGETS ${TARGET_NAME}
+	RUNTIME DESTINATION "bin")

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 Contributing
 ============
-We gladly accept contributions to Indivisible, however there are a few guidelines that must be followed.
+We gladly accept contributions to Indivisible (send Git patches to <deathsbreed@themusicinnoise.net>), however there are a few guidelines that must be followed.
 
 1) Copyright & Licensing
 ------------------------
@@ -8,7 +8,7 @@ The copyright of this project and all of its code, unless stated otherwise, belo
 
 2) Documentation
 ----------------
-All new features added must be well documented using DOxygen style comments. If your merge request adds a new feature and it is not well documented we will ask you to finish documenting the code before accepting a merge. This is simply so that both the maintainers of this repo and other users can understand the new API that bas been added.
+All new features added must be well documented using DOxygen style comments. If your patch adds a new feature and it is not well documented we will ask you to finish documenting the code before accepting a patch. This is simply so that both the maintainers of this repo and other users can understand the new API that bas been added.
 
 3) Code-Style
 -------------
@@ -16,8 +16,8 @@ The only aspects that will be religiously upheld for all contributions to this r
 
 Things that would be nice is if you could avoid having the lines being too long, and please avoid having more than one empty line in a row.
 
-4) Fractured Merge Requests
----------------------------
-Please make sure your merge requests are fractured into separate parts so that it may be easy for us to deal with them individually. The reason for this is to avoid having merge requests that both fix bugs and add features when in reality they should be separate requests. The only exception to this will be if the changes made to the code depend on one another to function properly.
+4) Fractured Patches
+--------------------
+Please make sure your patches are fractured into separate parts so that it may be easy for us to deal with them individually. The reason for this is to avoid having patches that both fix bugs and add features when in reality they should be separate requests. The only exception to this will be if the changes made to the code depend on one another to function properly.
 
-If your merge request meets all these requirements and is passed by one of the moderators it will be merged into the main repo.
+If your patch meets all these requirements and is passed by one of the moderators it will be merged into the main repo.

README.md

@@ -9,6 +9,7 @@ Building
 There are multiple dependencies to install before compiling the project:
 - CMake
 - GMP
+- OpenMP
 
 Once the dependencies are installed you can compile by running the following from the root directory of the project:
 ```bash
@@ -21,7 +22,7 @@ To build a release build run `cmake -DCMAKE_BUILD_TYPE=Release ..` instead.
 
 Contributing
 ------------
-If you would like to contribute to Uhn then please read the [contributing file](/CONTRIBUTING.md) before creating a merge request.
+If you would like to contribute to Indivisible then please read the [contributing file](/CONTRIBUTING.md) before sending a patch. You may send the patches to <deathsbreed@themusicinnoise.net>.
 
 License
 -------

src/files.c

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2017  Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+ * Author: Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "files.h"
+#include <stdio.h>
+#include <gmp.h>
+#include <assert.h>
+
+int inputPrimes(char *file, List *list) {
+	// Assert safeguards
+	assert(file);
+	assert(list);
+
+	FILE *in = fopen(file, "r");
+	if(!in) return 1;
+	mpz_t n;
+	mpz_init(n);
+	while(mpz_inp_raw(n, in))
+		if(addToList(list, n) == 1) return 3;
+
+	mpz_clear(n);
+
+	if(fclose(in)) return 2;
+	return 0;
+}
+
+int outputPrimes(char *file, List *list, size_t startPos) {
+	// Assert safeguards
+	assert(file);
+	assert(list);
+
+	FILE *out = fopen(file, "a");
+	if(!out) return 1;
+
+	printf("Saving primes to `%s'...\n", file);
+	puts("0%");
+	for(size_t i = startPos; i < list->end; ++i) {
+		if(!mpz_out_raw(out, list->list[i])) return 3;
+		if(i - startPos == (list->end - startPos) / 4) puts("25%");
+		else if(i - startPos == (list->end - startPos) / 2) puts("50%");
+		else if(i - startPos == (list->end - startPos) * 3 / 4) puts("75%");
+	}
+	puts("100%");
+
+	if(fclose(out)) return 2;
+	return 0;
+}
+
+int exportPrimes(char *efile, char *dfile, int base) {
+	// Assert safeguards
+	assert(efile);
+	assert(dfile);
+
+	FILE *in = fopen(dfile, "r");
+	FILE *out = fopen(efile, "w");
+	if(!in || !out) return 1;
+
+	printf("Exporting primes to `%s'...\n", efile);
+	mpz_t n;
+	mpz_init(n);
+	while(mpz_inp_raw(n, in)) {
+		if(!mpz_out_str(out, base, n)) return 3;
+		fprintf(out, "\n");
+	}
+
+	if(fclose(in) || fclose(out)) return 2;
+
+	return 0;
+}

src/files.h

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2017  Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+ * Author: Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @file files.h
+ * @author Deathsbreed <deathsbreed@themusicinnoise.net>
+ * @brief Functions to deal with file I/O of primes.
+ * @details Functions that input, output, and export primes from/to files.
+ */
+#pragma once
+#include "list.h"
+
+/**
+ * @brief Load primes from an Indivisible file into a List.
+ * @param file File to input primes from.
+ * @param list List to load primes into.
+ * @returns If 0 then load was successful, if 1 then failed to open,
+ * if 2 failed to close, if 3 failed to allocate new memory to List
+ * (see `addToList()')
+ */
+int inputPrimes(char *file, List *list);
+
+/**
+ * @brief Output primes from a List into an Indivisible file.
+ * @param file File to output primes to.
+ * @param list List to read primes from.
+ * @param startPos The position in the List of primes at which to append
+ * to the file.
+ * @returns If 0 then load was successful, if 1 then failed to open,
+ * if 2 failed to close, if 3 failed when writing.
+ */
+int outputPrimes(char *file, List *list, size_t startPos);
+
+/**
+ * @brief Export primes from a List to a plain text file.
+ * @param efile File to export primes as plain text to.
+ * @param dfile File to read primes from.
+ * @param base The base in which the primes will be written.
+ * @returns If 0 then load was successful, if 1 then failed to open,
+ * if 2 failed to close, if 3 failed when writing.
+ */
+int exportPrimes(char *efile, char *dfile, int base);

src/list.c

@@ -1,43 +1,52 @@
+/*
+ * Copyright (C) 2017  Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+ * Author: Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include "list.h"
 #include <stdlib.h>
-#include <stdio.h>
 
 /**
  * This is the number of elements by which the list expands.
  */
 #define BLOCK_SIZE 1024
 
-void initList(List *restrict l) {
+int initList(List *restrict l) {
 	l->list = malloc(sizeof(mpz_t) * BLOCK_SIZE);
-	if(!l->list) {
-		fprintf(stderr, "Failed to allocate memory to list!\n");
-		exit(1);
-	}
+	if(!l->list) return 1;
 	l->size = BLOCK_SIZE;
 	l->end = 0;
+	return 0;
 }
 
 void deInitList(List *restrict l) {
-	for(size_t i = 0; i < l->size; ++i) {
+	for(size_t i = 0; i < l->end; ++i) {
 		mpz_clear(l->list[i]);
 	}
 	free(l->list);
 }
 
-void addToList(List *l, mpz_t n) {
+int addToList(List *restrict l, mpz_t n) {
 	if(l->end == l->size) {
 		l->size += BLOCK_SIZE;
-		if(l->size == 0) {
-			fprintf(stderr, "`l->size' has overflowed!\n");
-			exit(1);
-		}
 		void *tmp = realloc(l->list, sizeof(mpz_t) * l->size);
-		if(!tmp) {
-			fprintf(stderr, "Failed to allocate more memory to list!\n");
-			exit(1);
-		}
-		l->list = (mpz_t*)tmp;
+		if(!tmp) return 1;
+		l->list = tmp;
 	}
 	mpz_init(l->list[l->end]);
 	mpz_set(l->list[l->end++], n);
+	return 0;
 }

src/list.h

@@ -1,3 +1,21 @@
+/*
+ * Copyright (C) 2017  Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+ * Author: Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 /**
  * @file list.h
  * @author Deathsbreed <deathsbreed@themusicinnoise.net>
@@ -7,7 +25,6 @@
  */
 #pragma once
 #include <gmp.h>
-#include <stdbool.h>
 
 /**
  * @brief An infinitely expanding list type.
@@ -23,8 +40,9 @@ typedef struct {
  * @details Initialize the list and its variables, allocating memory
  * to the pointer array inside.
  * @param[in] l A pointer to a List type to be initialized.
+ * @returns Returns 0 if successful and 1 if failed.
  */
-void initList(List *restrict l);
+int initList(List *restrict l);
 
 /**
  * @brief Deinitialize a List.
@@ -38,5 +56,6 @@ void deInitList(List *restrict l);
  * @details Add item `n' at the end of a List type.
  * @param[out] l List to which the variable should be appended.
  * @param[in] n variable to be appended to the list.
+ * @returns Returns 0 if successful and 1 if failed.
  */
-void addToList(List *l, mpz_t n);
+int addToList(List *restrict l, mpz_t n);

src/main.c

@@ -1,13 +1,35 @@
+/*
+ * Copyright (C) 2017  Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+ * Author: Ortega Froysa, Nicolás <deathsbreed@themusicinnoise.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
 #include <stdbool.h>
 #include <unistd.h>
 #include <gmp.h>
+#include <omp.h>
+
+#include <sys/stat.h>
 
 #include "list.h"
+#include "files.h"
 
-#define VERSION "v0.6"
+#define VERSION "v1.0"
 
 static bool run;
 
@@ -15,14 +37,18 @@ void printUsage(char *progName);
 void leave();
 
 int main(int argc, char *argv[]) {
+	// Variables for argument parsing
 	bool f_help = false,
 		 f_version = false,
 		 f_quiet = false;
 	int base = 10;
-	char *file = NULL;
+	size_t n_prime = 0;
+	char *dfile = NULL;
+	char *efile = NULL;
 
+	// Parse commandline arguments
 	int c;
-	while((c = getopt(argc, argv, "hvqb:f:")) != -1) {
+	while((c = getopt(argc, argv, "hvqb:f:e:n:")) != -1) {
 		switch(c) {
 			case 'h':
 				f_help = true;
@@ -37,135 +63,244 @@ int main(int argc, char *argv[]) {
 				base = atoi(optarg);
 				if(base < 2 || base > 62) {
 					fprintf(stderr,
-							"Invalid base `%d'. Base must be between 2 and 62\n",
+							"Invalid base `%d'. Base must be between 2 and 62.\n",
 							base);
-					exit(1);
+					return 1;
 				}
 				break;
 			case 'f':
-				file = optarg;
+				dfile = optarg;
+				break;
+			case 'e':
+				efile = optarg;
+				break;
+			case 'n':
+				n_prime = atoi(optarg);
+				if(n_prime <= 2) {
+					fprintf(stderr,
+							"`n' must be larger than 2 (first two primes are 2 and 3).\n");
+					return 1;
+				}
 				break;
 			default:
 				printUsage(argv[0]);
-				exit(1);
+				return 1;
 		}
 	}
 
+	// Act based on which flags were used
 	if(f_help) {
 		printUsage(argv[0]);
+		puts("\nArguments:");
 		puts(" -h         print this help information");
 		puts(" -v         print version number of program");
 		puts(" -q         quiet mode");
-		puts(" -b <base>  base in which to print primes between 2 and 62");
-		puts(" -f <file>  file to save primes to");
+		puts(" -b <base>  base in which to print primes between 2 and 62 (default 10)");
+		puts(" -f <file>  file in/from which primes are stored and read from in raw format");
+		puts(" -e <file>  export input file to plain text format");
+		puts(" -n <n>     run until the 'n'th prime\n");
 		return 0;
 	} else if(f_version) {
 		printf("Indivisible %s\n", VERSION);
 		return 0;
+	} else if(f_quiet && !dfile) {
+		puts("Error: you cannot run in quiet mode without specifying a data file.");
+		printUsage(argv[0]);
+		return 0;
+	}
+
+	if(efile && !dfile) {
+		puts("Error: you must have a file to export to.");
+		printUsage(argv[0]);
+		return 0;
+	} else if(efile && dfile) {
+		int err = exportPrimes(efile, dfile, base);
+		if(err) {
+			if(err == 1) fprintf(stderr, "Error: failed to open files.\n");
+			else if(err == 2) fprintf(stderr, "Error: failed to close files.\n");
+			else if(err == 3) fprintf(stderr, "Error: failed to write to export file.\n");
+			return 1;
+		}
+		return 0;
+	}
+
+	if(!omp_get_cancellation()) {
+		puts("Warning: the OpenMP cancellation environment variable (`OMP_CANCELLATION') is not enabled.");
+		char in;
+		while(true) {
+			printf("[e]nable/[c]ontinue/[q]uit? ");
+			scanf("%c", &in);
+			if(in == 'e' || in == 'E') {
+				putenv("OMP_CANCELLATION=true");
+				execv(argv[0], argv);
+			} else if(in == 'c' || in == 'C') {
+				break;
+			} else if(in == 'q' || in == 'Q') {
+				return 0;
+			}
+		}
 	}
 
 	// Quit on ^C by setting `run = false'
 	run = true;
 	signal(SIGINT, leave);
 
-	if(f_quiet) {
-		puts("Use Ctrl+C (SIGINT) to exit.");
+	puts("Use Ctrl+C to exit.");
+
+	bool newFile = true;
+	if(dfile) {
+		struct stat s;
+		if(stat(dfile, &s) == 0) newFile = false;
 	}
+	// Last position added from file
+	size_t startPos = 0;
+
+	int exitCode = 0;
 
 	// Primes we've found
 	List primes;
-	initList(&primes);
+	if(initList(&primes) == 1) {
+		fprintf(stderr, "Failed to initialize primes list.\n");
+		exit(1);
+	}
 
 	// The number we're going to be testing for
 	mpz_t num;
 	mpz_init(num);
 
-	// Add 2, a known prime to this list
-	mpz_set_ui(num, 2);
-	addToList(&primes, num);
-	if(!f_quiet) {
-		if(mpz_out_str(stdout, base, num) == 0) {
-			fprintf(stderr, "Could not print to `stdout'!\n");
+	// Variable for sqrt of `num'
+	mpz_t numRoot;
+	mpz_init(numRoot);
+	// Index of the prime number above and closest to `numRoot'
+	size_t rootInd = 0;
+
+	if(newFile) {
+		// Add 2, a known prime to this list
+		mpz_set_ui(num, 2);
+		if(addToList(&primes, num) == 1) {
+			fprintf(stderr, "Failed to allocate more memory for list.\n");
+			exitCode = 1;
 			goto releaseMemory;
 		}
-		printf("\n");
-	}
-	mpz_add_ui(num, num, 1);
-
-	// Variable for half `num'
-	mpz_t halfNum;
-	mpz_init(halfNum);
-
-	do {
-		// Calculate half of `num'
-		mpz_fdiv_q_ui(halfNum, num, 2);
-		/**
-		 * Loop through primes we've found until we get to half of the number
-		 * we're analyzing
-		 */
-		for(size_t i = 0; mpz_cmp(primes.list[i], halfNum) < 0; ++i) {
-			// If `num' is divisible by a prime then go to the next number
-			if(mpz_divisible_p(num, primes.list[i]) != 0)
-				goto nextPrime;
+		// Add 3 as well to optimize the algorithm
+		mpz_set_ui(num, 3);
+		if(addToList(&primes, num) == 1) {
+			fprintf(stderr, "Failed to allocate more memory for list.\n");
+			exitCode = 1;
+			goto releaseMemory;
 		}
-
-		// `num' is a prime so we add it to the list and print it
-		addToList(&primes, num);
 		if(!f_quiet) {
-			if(mpz_out_str(stdout, base, num) == 0) {
-				fprintf(stderr, "Could not print to `stdout'!\n");
+			puts("2\n3");
+		}
+	} else {
+		// Load primes from file
+		int err = inputPrimes(dfile, &primes);
+		startPos = primes.end;
+
+		if(err == 0) {
+			printf("Loaded %zu primes.\n", primes.end);
+		} else {
+			if(err == 1)
+				fprintf(stderr, "Failed to open Indivisible file `%s'.\n", dfile);
+			else if(err == 2)
+				fprintf(stderr, "Failed to close Indivisible file `%s'.\n", dfile);
+			else if(err == 3)
+				fprintf(stderr, "Failed to allocate more memory for list.\n");
+			exitCode = 1;
+			goto releaseMemory;
+		}
+		/**
+		 * I set to `primes.end-1' because primes.end indicates the next new
+		 * element in the list that can be used, which is also equal to the total
+		 * number of elements in the list.
+		 */
+		mpz_set(num, primes.list[primes.end-1]);
+	}
+
+	while(run) {
+		mpz_add_ui(num, num, 2);
+
+		// Calculate the sqrt(num)
+		mpz_sqrt(numRoot, num);
+
+		while(mpz_cmp(primes.list[rootInd], numRoot) <= 0) {
+			if(++rootInd > primes.end) {
+				fprintf(stderr, "Error: `rootInd' surpassed `primes.end'.\n");
+				exitCode = 1;
 				goto releaseMemory;
 			}
-			printf("\n");
 		}
 
-nextPrime:
-		// Add 2 (skip even numbers since they're all divisible by 2)
-		mpz_add_ui(num, num, 2);
-	} while(run);
+		bool isPrime = true;
+		/**
+		 * Loop through primes we've found until we get to the sqrt of the
+		 * number we're analyzing. Also, skip `2' since we're not testing even
+		 * numbers.
+		 */
+		#pragma omp parallel
+		{
+			#pragma omp for
+			for(size_t i = 1; i < rootInd; ++i) {
+				if(mpz_divisible_p(num, primes.list[i])) {
+					#pragma omp atomic write
+					isPrime = false;
+					#pragma omp cancel for
+				}
+				#pragma omp cancellation point for
+			}
+		}
+
+		if(isPrime) {
+			// `num' is a prime so we add it to the list and print it
+			if(addToList(&primes, num) == 1) {
+				fprintf(stderr, "Failed to allocate more memory for list.\n");
+				exitCode = 1;
+				goto releaseMemory;
+			}
+			if(!f_quiet) {
+				if(!mpz_out_str(stdout, base, num))
+					fprintf(stderr, "Could not print to `stdout'!\n");
+				printf("\n");
+			}
+		}
+
+		if(primes.end == n_prime) break;
+	}
+
 
 	printf("Found %zu primes.\n", primes.end);
-	// Clear GMP variables
-	mpz_clear(halfNum);
-	mpz_clear(num);
 
-	if(file != NULL) {
-		FILE *outFile = fopen(file, "w+");
-		if(outFile == NULL) {
-			fprintf(stderr, "Failed create file `%s'.\n", file);
+	if(dfile) {
+		int err = outputPrimes(dfile, &primes, startPos);
+		if(err == 0) {
+			puts("Successfully saved primes.");
+		} else {
+			if(err == 1)
+				fprintf(stderr, "Failed to open/create file `%s'.\n", dfile);
+			else if(err == 2)
+				fprintf(stderr, "Failed to close file `%s'.\n", dfile);
+			else if(err == 3)
+				fprintf(stderr, "Failed while writing a prime to `%s'.\n", dfile);
+			exitCode = 1;
 			goto releaseMemory;
 		}
-		printf("Writing primes to `%s'...\n", file);
-		puts("0%");
-		for(size_t i = 0; i < primes.end; ++i) {
-			if(mpz_out_str(outFile, base, primes.list[i]) == 0) {
-				fprintf(stderr, "Error occurred while writing to file `%s'.\n", file);
-				goto releaseMemory;
-			}
-			fprintf(outFile, "\n");
-			if(i == primes.end / 4) puts("25%");
-			else if(i == primes.end / 2) puts("50%");
-			else if(i == primes.end * 3 / 4) puts("75%");
-		}
-		if(fclose(outFile) != 0) {
-			fprintf(stderr, "Failed to close file `%s'.\n", file);
-			goto releaseMemory;
-		}
-		puts("100%");
-		puts("Finished writing primes.");
+
 	}
 
 releaseMemory:
 	puts("Clearing memory...");
+	// Clear GMP variables
+	mpz_clear(numRoot);
+	mpz_clear(num);
 	// Deinitialize the list
 	deInitList(&primes);
 
 	puts("Exit successful.");
-	return 0;
+	return exitCode;
 }
 
 void printUsage(char *progName) {
-	printf("%s [options...]\n", progName);
+	printf("%s [[-f <file> [-e <file> | -q]] [-b <base>] [-n <n>] | [-h] | [-v]]\n", progName);
 }
 
 void leave() { run = false; }