Refactor code into a library and implement basic file management methods

1 files changed, 145 insertions, 0 deletions

diff --git a/examples/c4cat_dyn.c b/examples/c4cat_dyn.c
new file mode 100644
index 0000000..92da979
--- /dev/null
+++ b/examples/c4cat_dyn.c
@@ -0,0 +1,145 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <dlfcn.h>
+#include <assert.h>
+
+#define CC4GROUP_DYNAMIC_LOAD
+#include "cc4group.h"
+#undef CC4GROUP_DYNAMIC_LOAD
+
+CC4Group_API* cc4group_dyn;
+#define cc4group (*cc4group_dyn)
+
+bool catNormalFile(const char* const path, const off_t size)
+{
+	int file = open(path, O_RDONLY);
+	if(file == -1)
+	{
+		fprintf(stderr, "ERROR: Reading \"%s\": %s\n", path, strerror(errno));
+		return false;
+	}
+
+	void* mappedFile = mmap(NULL, size, PROT_READ, MAP_PRIVATE, file, 0);
+
+	if(close(file) == -1)
+	{
+		fprintf(stderr, "ERROR: Closing \"%s\": %s\n", path, strerror(errno));
+	}
+
+	if(mappedFile == MAP_FAILED)
+	{
+		fprintf(stderr, "ERROR: Mapping \"%s\" for reading: %s\n", path, strerror(errno));
+		return false;
+	}
+
+	if(write(STDOUT_FILENO, mappedFile, size) != size)
+	{
+		fprintf(stderr, "ERROR: Writing file contents of \"%s\" to stdout: %s\n", path, strerror(errno));
+	}
+
+	if(munmap(mappedFile, size) == -1)
+	{
+		fprintf(stderr, "ERROR: Unmapping \"%s\": %s\n", path, strerror(errno));
+	}
+
+	return true;
+}
+
+bool catFileWithPathsAndSize(const char* const completePath, const char* const groupPath, off_t fileSize)
+{
+	if(strcmp(groupPath, completePath) == 0)
+	{
+		return catNormalFile(completePath, fileSize);
+	}
+
+	const char* pathInGroup = completePath + strlen(groupPath) + 1;
+	CC4Group* group = cc4group.new();
+	if(!cc4group.openExisting(group, groupPath))
+	{
+		fprintf(stderr, "ERROR: Can not open group file \"%s\": %s\n", groupPath, cc4group.getErrorMessage(group));
+		return false;
+	}
+
+	const void* data;
+	size_t size;
+	bool success = cc4group.getEntryData(group, pathInGroup, &data, &size);
+
+	if(success)
+	{
+		if(write(STDOUT_FILENO, data, size) != (ssize_t)size)
+		{
+			fprintf(stderr, "ERROR: Writing file contents of \"%s\" to stdout: %s\n", completePath, strerror(errno));
+		}
+	}
+	else
+	{
+		fprintf(stderr, "ERROR: Reading \"%s\" from \"%s\": %s\n", pathInGroup, groupPath, strerror(ENOENT));
+	}
+
+	cc4group.delete(group);
+
+	return success;
+}
+
+bool catFile(const char* const completePath)
+{
+	struct stat st;
+
+	char* groupPath = strdup(completePath);
+	char* slash;
+	for(slash = groupPath + strlen(groupPath); slash != NULL; slash = strrchr(groupPath, '/'))
+	{
+		*slash = '\0';
+		if(stat(groupPath, &st) == 0 && !S_ISDIR(st.st_mode))
+		{
+			break;
+		}
+	}
+
+	bool success;
+	if(slash == NULL)
+	{
+		fprintf(stderr, "ERROR: Reading \"%s\": %s\n", completePath, strerror(ENOENT));
+		success = false;
+	}
+	else
+	{
+		success = catFileWithPathsAndSize(completePath, groupPath, st.st_size);
+	}
+
+	free(groupPath);
+	return success;
+}
+
+int main(int argc, char* argv[])
+{
+	void* dl = dlopen("./libcc4group_dyn.so", RTLD_LAZY);
+	assert(dl);
+
+	dlerror();
+	cc4group_dyn = dlsym(dl, "cc4group");
+	assert(!dlerror());
+
+	if(argc < 2)
+	{
+		fprintf(stderr, "USAGE: %s <entry path>...\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	bool success = true;
+	for(int i = 1; i < argc; ++i)
+	{
+		success &= catFile(argv[i]);
+	}
+
+	dlclose(dl);
+
+	return success ? EXIT_SUCCESS : EXIT_FAILURE;
+}