diff --git a/ansicodes/Makefile b/ansicodes/Makefile new file mode 100644 index 0000000..d246f81 --- /dev/null +++ b/ansicodes/Makefile @@ -0,0 +1,14 @@ +CC = gcc +CFLAGS = -Wall -O2 + +TARGET = main.elf +SRC = main.c + +#LDFLAGS = + +$(TARGET): $(SRC) + @echo CC $@ + @$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) + +clean: + rm -f $(TARGET) diff --git a/ansicodes/ansi.h b/ansicodes/ansi.h new file mode 100644 index 0000000..627fa51 --- /dev/null +++ b/ansicodes/ansi.h @@ -0,0 +1,64 @@ +#ifndef ANSI_H +#define ANSI_H + +/* Set this to make all the codes no-ops */ +//#define ANSI_DISABLE + +#ifndef ANSI_DISABLE +#define ESC(x) x +#else +#define ESC(x) +#endif + +/* Reset */ +#define ANSI_RESET ESC("\033[0m") + +/* Styles */ +#define ANSI_BOLD ESC("\033[1m") +#define ANSI_DIM ESC("\033[2m") +#define ANSI_UNDER ESC("\033[4m") +#define ANSI_BLINK ESC("\033[5m") +#define ANSI_REV ESC("\033[7m") +#define ANSI_HIDDEN ESC("\033[8m") + +/* Foreground colors */ +#define ANSI_FG_BLACK ESC("\033[30m") +#define ANSI_FG_RED ESC("\033[31m") +#define ANSI_FG_GREEN ESC("\033[32m") +#define ANSI_FG_YELLOW ESC("\033[33m") +#define ANSI_FG_BLUE ESC("\033[34m") +#define ANSI_FG_MAGENTA ESC("\033[35m") +#define ANSI_FG_CYAN ESC("\033[36m") +#define ANSI_FG_WHITE ESC("\033[37m") + +/* Bright foreground colors */ +#define ANSI_FG_BBLACK ESC("\033[90m") +#define ANSI_FG_BRED ESC("\033[91m") +#define ANSI_FG_BGREEN ESC("\033[92m") +#define ANSI_FG_BYELLOW ESC("\033[93m") +#define ANSI_FG_BBLUE ESC("\033[94m") +#define ANSI_FG_BMAGENTA ESC("\033[95m") +#define ANSI_FG_BCYAN ESC("\033[96m") +#define ANSI_FG_BWHITE ESC("\033[97m") + +/* Background colors */ +#define ANSI_BG_BLACK ESC("\033[40m") +#define ANSI_BG_RED ESC("\033[41m") +#define ANSI_BG_GREEN ESC("\033[42m") +#define ANSI_BG_YELLOW ESC("\033[43m") +#define ANSI_BG_BLUE ESC("\033[44m") +#define ANSI_BG_MAGENTA ESC("\033[45m") +#define ANSI_BG_CYAN ESC("\033[46m") +#define ANSI_BG_WHITE ESC("\033[47m") + +/* Bright background colors */ +#define ANSI_BG_BBLACK ESC("\033[100m") +#define ANSI_BG_BRED ESC("\033[101m") +#define ANSI_BG_BGREEN ESC("\033[102m") +#define ANSI_BG_BYELLOW ESC("\033[103m") +#define ANSI_BG_BBLUE ESC("\033[104m") +#define ANSI_BG_BMAGENTA ESC("\033[105m") +#define ANSI_BG_BCYAN ESC("\033[106m") +#define ANSI_BG_BWHITE ESC("\033[107m") + +#endif // ANSI_H diff --git a/ansicodes/main.c b/ansicodes/main.c new file mode 100644 index 0000000..bf9773f --- /dev/null +++ b/ansicodes/main.c @@ -0,0 +1,58 @@ +#include "ansi.h" +#include +#include +#include +#include + +int main(int argc, char *argv[]) { + + if (!isatty(STDOUT_FILENO) || !(getenv("TERM") && strcmp(getenv("TERM"), "dumb") != 0)) { + printf("This terminal does not seem to support ANSI\n"); + exit(EXIT_FAILURE); + } + + printf(ANSI_BOLD "ABCDE" ANSI_RESET "\n"); + printf(ANSI_DIM "ABCDE" ANSI_RESET "\n"); + printf(ANSI_UNDER "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BLINK "ABCDE" ANSI_RESET "\n"); + printf(ANSI_REV "ABCDE" ANSI_RESET "\n"); + printf(ANSI_HIDDEN "ABCDE" ANSI_RESET "\n"); + + printf(ANSI_FG_BLACK "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_RED "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_GREEN "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_YELLOW "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_BLUE "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_MAGENTA "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_CYAN "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_WHITE "ABCDE" ANSI_RESET "\n"); + + printf(ANSI_FG_BBLACK "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_BRED "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_BGREEN "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_BYELLOW "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_BBLUE "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_BMAGENTA "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_BCYAN "ABCDE" ANSI_RESET "\n"); + printf(ANSI_FG_BWHITE "ABCDE" ANSI_RESET "\n"); + + printf(ANSI_BG_BLACK "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_RED "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_GREEN "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_YELLOW "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_BLUE "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_MAGENTA "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_CYAN "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_WHITE "ABCDE" ANSI_RESET "\n"); + + printf(ANSI_BG_BBLACK "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_BRED "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_BGREEN "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_BYELLOW "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_BBLUE "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_BMAGENTA "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_BCYAN "ABCDE" ANSI_RESET "\n"); + printf(ANSI_BG_BWHITE "ABCDE" ANSI_RESET "\n"); + + exit(EXIT_SUCCESS); +} diff --git a/config_ini/conf.c b/config_ini/conf.c index 48b5b8f..1ed15e7 100644 --- a/config_ini/conf.c +++ b/config_ini/conf.c @@ -57,6 +57,13 @@ Config *config_load(const char *filename) { return cfg; } +ConfigEntry *config_get_next(ConfigEntry *entry, int *index) { + if (!entry) + return NULL; + + return (0 == (*index)++) ? entry : entry->next; +} + /* Get value for a key */ const char *config_get(Config *cfg, const char *key) { for (ConfigEntry *e = cfg->head; e; e = e->next) { diff --git a/config_ini/conf.h b/config_ini/conf.h index 415a7e0..e25470c 100644 --- a/config_ini/conf.h +++ b/config_ini/conf.h @@ -11,8 +11,9 @@ typedef struct { ConfigEntry *head; } Config; -Config *config_load(const char *filename); -const char *config_get(Config *cfg, const char *key); -void config_free(Config *cfg); +Config *config_load(const char *filename); +const char *config_get(Config *cfg, const char *key); +ConfigEntry *config_get_next(ConfigEntry *entry, int *index); +void config_free(Config *cfg); #endif // CONF_H diff --git a/config_ini/main.c b/config_ini/main.c index b21a06f..32b0a55 100644 --- a/config_ini/main.c +++ b/config_ini/main.c @@ -1,8 +1,53 @@ #include "conf.h" +#include #include +#include +#include +#include -// Example usage int main(void) { + const char *home = getenv("HOME"); + if (!home) { + perror("home"); + exit(EXIT_FAILURE); + } + + /* Potentially scope this to preserve stack if thats an issue */ + char config_dir[256]; + char config_file[512]; + + { + snprintf(config_dir, sizeof(config_dir), "%s/.config", home); + snprintf(config_file, sizeof(config_file), "%s/mytool.ini", config_dir); + + /* Ensure ~/.config exists */ + struct stat st; + if (stat(config_dir, &st) == 0) { + if (!S_ISDIR(st.st_mode)) { + printf("Creating config directory\n"); + mkdir(config_dir, 0700); + perror("mkdir ~/.config"); + } + } + + /* Create config file */ + int fd = open(config_file, O_RDWR | O_CREAT, 0600); + if (fd < 0) { + perror("open mytool.ini"); + return 1; + } + close(fd); + } + + FILE *f = fopen(config_file, "r"); + if (!f) { + perror("fopen"); + return 1; + } + /* Parsing here ... */ + fclose(f); + unlink(config_file); + Config *cfg = config_load("config.ini"); if (!cfg) { fprintf(stderr, "Failed to load config.ini\n"); @@ -15,6 +60,15 @@ int main(void) { printf("Username: %s\n", user ? user : "(not set)"); printf("Password: %s\n", pass ? pass : "(not set)"); + printf("-----\n"); + + /* Iterate over config values */ + ConfigEntry *c = cfg->head; + int idx = 0; + while ((c = config_get_next(c, &idx)) != NULL) { + printf("%s = %s\n", c->key, c->value); + } + config_free(cfg); return 0; } diff --git a/crc32/Makefile b/crc32/Makefile new file mode 100644 index 0000000..7cf024d --- /dev/null +++ b/crc32/Makefile @@ -0,0 +1,12 @@ +CC ?= gcc +CFLAGS ?= -Wall -O2 + +TARGET = test.elf +SRC = test.c + +$(TARGET): $(SRC) + @echo CC $@ + @$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) + +clean: + rm -f $(TARGET) diff --git a/crc32/crc32.h b/crc32/crc32.h new file mode 100644 index 0000000..29552eb --- /dev/null +++ b/crc32/crc32.h @@ -0,0 +1,78 @@ +#ifndef CRC32_H +#define CRC32_H + +#include +#include + +/* + * CRC-32 (IEEE 802.3, gzip, zip, etc.) + * Polynomial: 0xEDB88320 (reflected) + * Init value: 0xFFFFFFFF + * Final XOR: 0xFFFFFFFF + */ + +#define CRC32_INIT ((uint32_t)0xFFFFFFFFU) +#define CRC32_XOR ((uint32_t)0xFFFFFFFFU) + +static const uint32_t crc32_table[256] = { + 0x00000000U, 0x77073096U, 0xEE0E612CU, 0x990951BAU, 0x076DC419U, 0x706AF48FU, 0xE963A535U, 0x9E6495A3U, 0x0EDB8832U, + 0x79DCB8A4U, 0xE0D5E91EU, 0x97D2D988U, 0x09B64C2BU, 0x7EB17CBDU, 0xE7B82D07U, 0x90BF1D91U, 0x1DB71064U, 0x6AB020F2U, + 0xF3B97148U, 0x84BE41DEU, 0x1ADAD47DU, 0x6DDDE4EBU, 0xF4D4B551U, 0x83D385C7U, 0x136C9856U, 0x646BA8C0U, 0xFD62F97AU, + 0x8A65C9ECU, 0x14015C4FU, 0x63066CD9U, 0xFA0F3D63U, 0x8D080DF5U, 0x3B6E20C8U, 0x4C69105EU, 0xD56041E4U, 0xA2677172U, + 0x3C03E4D1U, 0x4B04D447U, 0xD20D85FDU, 0xA50AB56BU, 0x35B5A8FAU, 0x42B2986CU, 0xDBBBC9D6U, 0xACBCF940U, 0x32D86CE3U, + 0x45DF5C75U, 0xDCD60DCFU, 0xABD13D59U, 0x26D930ACU, 0x51DE003AU, 0xC8D75180U, 0xBFD06116U, 0x21B4F4B5U, 0x56B3C423U, + 0xCFBA9599U, 0xB8BDA50FU, 0x2802B89EU, 0x5F058808U, 0xC60CD9B2U, 0xB10BE924U, 0x2F6F7C87U, 0x58684C11U, 0xC1611DABU, + 0xB6662D3DU, 0x76DC4190U, 0x01DB7106U, 0x98D220BCU, 0xEFD5102AU, 0x71B18589U, 0x06B6B51FU, 0x9FBFE4A5U, 0xE8B8D433U, + 0x7807C9A2U, 0x0F00F934U, 0x9609A88EU, 0xE10E9818U, 0x7F6A0DBBU, 0x086D3D2DU, 0x91646C97U, 0xE6635C01U, 0x6B6B51F4U, + 0x1C6C6162U, 0x856530D8U, 0xF262004EU, 0x6C0695EDU, 0x1B01A57BU, 0x8208F4C1U, 0xF50FC457U, 0x65B0D9C6U, 0x12B7E950U, + 0x8BBEB8EAU, 0xFCB9887CU, 0x62DD1DDFU, 0x15DA2D49U, 0x8CD37CF3U, 0xFBD44C65U, 0x4DB26158U, 0x3AB551CEU, 0xA3BC0074U, + 0xD4BB30E2U, 0x4ADFA541U, 0x3DD895D7U, 0xA4D1C46DU, 0xD3D6F4FBU, 0x4369E96AU, 0x346ED9FCU, 0xAD678846U, 0xDA60B8D0U, + 0x44042D73U, 0x33031DE5U, 0xAA0A4C5FU, 0xDD0D7CC9U, 0x5005713CU, 0x270241AAU, 0xBE0B1010U, 0xC90C2086U, 0x5768B525U, + 0x206F85B3U, 0xB966D409U, 0xCE61E49FU, 0x5EDEF90EU, 0x29D9C998U, 0xB0D09822U, 0xC7D7A8B4U, 0x59B33D17U, 0x2EB40D81U, + 0xB7BD5C3BU, 0xC0BA6CADU, 0xEDB88320U, 0x9ABFB3B6U, 0x03B6E20CU, 0x74B1D29AU, 0xEAD54739U, 0x9DD277AFU, 0x04DB2615U, + 0x73DC1683U, 0xE3630B12U, 0x94643B84U, 0x0D6D6A3EU, 0x7A6A5AA8U, 0xE40ECF0BU, 0x9309FF9DU, 0x0A00AE27U, 0x7D079EB1U, + 0xF00F9344U, 0x8708A3D2U, 0x1E01F268U, 0x6906C2FEU, 0xF762575DU, 0x806567CBU, 0x196C3671U, 0x6E6B06E7U, 0xFED41B76U, + 0x89D32BE0U, 0x10DA7A5AU, 0x67DD4ACCU, 0xF9B9DF6FU, 0x8EBEEFF9U, 0x17B7BE43U, 0x60B08ED5U, 0xD6D6A3E8U, 0xA1D1937EU, + 0x38D8C2C4U, 0x4FDFF252U, 0xD1BB67F1U, 0xA6BC5767U, 0x3FB506DDU, 0x48B2364BU, 0xD80D2BDAU, 0xAF0A1B4CU, 0x36034AF6U, + 0x41047A60U, 0xDF60EFC3U, 0xA867DF55U, 0x316E8EEFU, 0x4669BE79U, 0xCB61B38CU, 0xBC66831AU, 0x256FD2A0U, 0x5268E236U, + 0xCC0C7795U, 0xBB0B4703U, 0x220216B9U, 0x5505262FU, 0xC5BA3BBEU, 0xB2BD0B28U, 0x2BB45A92U, 0x5CB36A04U, 0xC2D7FFA7U, + 0xB5D0CF31U, 0x2CD99E8BU, 0x5BDEAE1DU, 0x9B64C2B0U, 0xEC63F226U, 0x756AA39CU, 0x026D930AU, 0x9C0906A9U, 0xEB0E363FU, + 0x72076785U, 0x05005713U, 0x95BF4A82U, 0xE2B87A14U, 0x7BB12BAEU, 0x0CB61B38U, 0x92D28E9BU, 0xE5D5BE0DU, 0x7CDCEFB7U, + 0x0BDBDF21U, 0x86D3D2D4U, 0xF1D4E242U, 0x68DDB3F8U, 0x1FDA836EU, 0x81BE16CDU, 0xF6B9265BU, 0x6FB077E1U, 0x18B74777U, + 0x88085AE6U, 0xFF0F6A70U, 0x66063BCAU, 0x11010B5CU, 0x8F659EFFU, 0xF862AE69U, 0x616BFFD3U, 0x166CCF45U, 0xA00AE278U, + 0xD70DD2EEU, 0x4E048354U, 0x3903B3C2U, 0xA7672661U, 0xD06016F7U, 0x4969474DU, 0x3E6E77DBU, 0xAED16A4AU, 0xD9D65ADCU, + 0x40DF0B66U, 0x37D83BF0U, 0xA9BCAE53U, 0xDEBB9EC5U, 0x47B2CF7FU, 0x30B5FFE9U, 0xBDBDF21CU, 0xCABAC28AU, 0x53B39330U, + 0x24B4A3A6U, 0xBAD03605U, 0xCDD70693U, 0x54DE5729U, 0x23D967BFU, 0xB3667A2EU, 0xC4614AB8U, 0x5D681B02U, 0x2A6F2B94U, + 0xB40BBE37U, 0xC30C8EA1U, 0x5A05DF1BU, 0x2D02EF8DU, +}; + +static inline uint32_t crc32_update_raw(uint32_t crc, const void *data, unsigned int length) { + const uint8_t *p = (const uint8_t *)data; + while (length--) { + crc = (crc >> 8) ^ crc32_table[(crc ^ *p++) & 0xFFU]; + } + return crc; +} + +static inline uint32_t crc32(const void *data, unsigned int length) { + uint32_t crc = CRC32_INIT; + crc = crc32_update_raw(crc, data, length); + return crc ^ CRC32_XOR; +} + +static inline uint32_t crc32_init(void) { + return CRC32_INIT; +} + +static inline uint32_t crc32_update(uint32_t crc, const void *data, unsigned int length) { + return crc32_update_raw(crc, data, length); +} + +static inline uint32_t crc32_finalize(uint32_t crc) { + return crc ^ CRC32_XOR; +} + +#undef CRC32_XOR +#undef CRC32_INIT + +#endif // CRC32_H diff --git a/crc32/crc32_nolookup.h b/crc32/crc32_nolookup.h new file mode 100644 index 0000000..c351fad --- /dev/null +++ b/crc32/crc32_nolookup.h @@ -0,0 +1,33 @@ +#ifndef CRC32_NOLOOKUP_H +#define CRC32_NOLOOKUP_H + +#include +#include + +/* + * CRC-32 (IEEE 802.3) implementation + * Polynomial: 0xEDB88320 (reflected) + * Initial value: 0xFFFFFFFF + * Final XOR: 0xFFFFFFFF + * Input reflected: Yes + * Output reflected: Yes + */ + +static inline uint32_t crc32_ieee(const void *data, size_t len) { + const uint8_t *p = (const uint8_t *)data; + uint32_t crc = 0xFFFFFFFF; + + while (len--) { + crc ^= *p++; + for (int i = 0; i < 8; i++) { + if (crc & 1) + crc = (crc >> 1) ^ 0xEDB88320; + else + crc >>= 1; + } + } + + return crc ^ 0xFFFFFFFF; +} + +#endif // CRC32_H diff --git a/crc32/test.c b/crc32/test.c new file mode 100644 index 0000000..6d11be8 --- /dev/null +++ b/crc32/test.c @@ -0,0 +1,33 @@ +#include "crc32.h" +#include "crc32_nolookup.h" +#include +#include + +int main(void) { + assert(crc32("123456789", 9) == 0xCBF43926); + assert(crc32("", 0) == 0x00000000); + assert(crc32("a", 1) == 0xE8B7BE43); + assert(crc32("A", 1) == 0xD3D99E8B); + assert(crc32("hello", 5) == 0x3610A686); + assert(crc32("The quick brown fox jumps over the lazy dog", 43) == 0x414FA339); + assert(crc32("The quick brown fox jumps over the lazy dog.", 44) == 0x519025E9); + + /* Keep in mind the update api requires initialization and finalization */ + uint32_t crc = crc32_init(); + crc = crc32_update_raw(crc, "a", 1); + crc = crc32_finalize(crc); + + assert(crc == crc32("a", 1)); + assert(crc == 0xE8B7BE43); + + assert(crc32_ieee("123456789", 9) == 0xCBF43926); + assert(crc32_ieee("", 0) == 0x00000000); + assert(crc32_ieee("a", 1) == 0xE8B7BE43); + assert(crc32_ieee("A", 1) == 0xD3D99E8B); + assert(crc32_ieee("hello", 5) == 0x3610A686); + assert(crc32_ieee("The quick brown fox jumps over the lazy dog", 43) == 0x414FA339); + assert(crc32_ieee("The quick brown fox jumps over the lazy dog.", 44) == 0x519025E9); + + printf("All good!\n"); + return 0; +} diff --git a/freelist/hexdump.c b/freelist/hexdump.c index cdf2121..3cfba4b 100644 --- a/freelist/hexdump.c +++ b/freelist/hexdump.c @@ -2,30 +2,31 @@ #include #include #include +#include +#include +#include -void hexdump(const void *data, size_t size) { +void hexdump(const void *data, const size_t size, const size_t width) { const unsigned char *p = (const unsigned char *)data; size_t i, j; - for (i = 0; i < size; i += 16) { - // Print offset + for (i = 0; i < size; i += width) { printf("%08zx ", i); - // Print hex bytes - for (j = 0; j < 16; j++) { + for (j = 0; j < width; j++) { if (i + j < size) { printf("%02X ", p[i + j]); } else { - printf(" "); // padding for incomplete lines + printf(" "); } - if (j == 7) - printf(" "); // extra space in middle + + if ((j + 1) % 8 == 0) + printf(" "); } printf(" |"); - // Print ASCII characters - for (j = 0; j < 16 && i + j < size; j++) { + for (j = 0; j < width && i + j < size; j++) { unsigned char c = p[i + j]; printf("%c", isprint(c) ? c : '.'); } diff --git a/freelist/hexdump.h b/freelist/hexdump.h index d01a907..c057eac 100644 --- a/freelist/hexdump.h +++ b/freelist/hexdump.h @@ -3,6 +3,6 @@ #include -void hexdump(const void *data, size_t size); +void hexdump(const void *data, const size_t size, const size_t width); #endif // HEXDUMP_H diff --git a/freelist/main.c b/freelist/main.c index ffb2068..5e3f2d6 100644 --- a/freelist/main.c +++ b/freelist/main.c @@ -47,7 +47,7 @@ int main() { const uint32_t head_crc = crc32(headblock, BUFFER_SIZE / 2); /* Display a nice hexdump so you can see the layout */ - hexdump(headblock, BUFFER_SIZE * 2); + hexdump(headblock, BUFFER_SIZE * 2, 32); if (!fl_init(&fl, (uintptr_t)mem, BUFFER_SIZE, sizeof(Vec3))) { printf("Freelist failed to initialize!\n"); @@ -130,7 +130,7 @@ int main() { assert(crc32(tailblock, BUFFER_SIZE / 2) == tail_crc); /* Hexdump the heap, free the block and declare victory */ - hexdump(headblock, BUFFER_SIZE * 2); + hexdump(headblock, BUFFER_SIZE * 2, 32); free(headblock); printf("All tests passed!\n"); return 0; diff --git a/getopt/Makefile b/getopt/Makefile new file mode 100644 index 0000000..10168b0 --- /dev/null +++ b/getopt/Makefile @@ -0,0 +1,15 @@ +CC = gcc +CFLAGS = -Wall -O2 + +all: getopt.elf getopt_long.elf + +getopt.elf: getopt.c + @echo CC $@ + @$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) + +getopt_long.elf: getopt_long.c + @echo CC $@ + @$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) + +clean: + rm -f *.elf diff --git a/getopt/getopt.c b/getopt/getopt.c new file mode 100644 index 0000000..2e5c8b4 --- /dev/null +++ b/getopt/getopt.c @@ -0,0 +1,15 @@ +#include +#include + +int main(int argc, char *argv[]) { + int opt; + while ((opt = getopt(argc, argv, "hf:o:")) != -1) { + switch (opt) { + case 'h': puts("Help"); break; + case 'f': printf("File: %s\n", optarg); break; + case 'o': printf("Output: %s\n", optarg); break; + default: fprintf(stderr, "Usage: %s [-h] [-f file] [-o output]\n", argv[0]); return 1; + } + } + return 0; +} diff --git a/getopt/getopt_long.c b/getopt/getopt_long.c new file mode 100644 index 0000000..a888e6e --- /dev/null +++ b/getopt/getopt_long.c @@ -0,0 +1,38 @@ +#include +#include +#include + +#define VERSION "0.0.1" + +int main(int argc, char *argv[]) { + int opt; + int option_index = 0; + static struct option long_opts[] = { + {"help", no_argument, 0, 'h'}, + {"file", required_argument, 0, 'f'}, + {"output", required_argument, 0, 'o'}, + {"version", no_argument, 0, 'v'}, + {0, 0, 0, 0}, + }; + + int has_file = 0; + char a[128]; + + while ((opt = getopt_long(argc, argv, "hvf:o:", long_opts, &option_index)) != -1) { + switch (opt) { + case 'h': puts("Help"); break; + case 'f': + printf("File: %s\n", optarg); + strncpy(a, optarg, 127); + has_file = 1; + break; + case 'o': printf("Output: %s\n", optarg); break; + case 'v': printf("Version: v%s\n", VERSION); break; + default: return 1; + } + } + + if (has_file) + printf("Using file: %s\n", a); + return 0; +} diff --git a/mmap_file/.gitignore b/mmap_file/.gitignore new file mode 100644 index 0000000..f0014c4 --- /dev/null +++ b/mmap_file/.gitignore @@ -0,0 +1 @@ +mapped.txt diff --git a/mmap_file/Makefile b/mmap_file/Makefile new file mode 100644 index 0000000..70f6219 --- /dev/null +++ b/mmap_file/Makefile @@ -0,0 +1,12 @@ +CC ?= gcc +CFLAGS ?= -Wall -O2 + +TARGET = main.elf +SRC = mmap_file.c + +$(TARGET): $(SRC) + @echo CC $@ + @$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) + +clean: + rm -f $(TARGET) diff --git a/mmap_file/mmap_file.c b/mmap_file/mmap_file.c new file mode 100644 index 0000000..781f05f --- /dev/null +++ b/mmap_file/mmap_file.c @@ -0,0 +1,56 @@ +#include +#include +#include +#include +#include +#include + +#define FILE_PATH "mapped.txt" +#define FILE_SIZE 4096 + +int main() { + int fd = open(FILE_PATH, O_RDWR | O_CREAT, 0644); + if (fd == -1) { + perror("open"); + return 1; + } + + /* We want some space to write */ + if (ftruncate(fd, FILE_SIZE) == -1) { + perror("ftruncate"); + close(fd); + return 1; + } + + /* NULL means we do not care where the mapping goes, anywhere in canonical memory will do + * PROT_READ/WRITE are just protection flags that allows our process rw rights + * MAP_SHARED means our (real time, or close to) changes are visible to other processes mmping the same file */ + void *file_memory = mmap(NULL, FILE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + if (file_memory == MAP_FAILED) { + perror("mmap"); + close(fd); + return 1; + } + + const char *message = "This is written to file!"; + strncpy(file_memory, message, strlen(message) + 1); + + /* Re-truncate the file to known length, otherwise the entire buffer + * (4k, with garbage from whatever the kernel gave us) will be in the file*/ + if (ftruncate(fd, strnlen(message, FILE_SIZE + 1)) == -1) { + perror("ftruncate"); + close(fd); + return 1; + } + + printf("Mapped region content: %s\n", (char *)file_memory); + + munmap(file_memory, FILE_SIZE); + + close(fd); + + /* Optional finishing step, but i assume you want to inspect the file */ + // remove(file_path); + + return 0; +} diff --git a/syslog/Makefile b/syslog/Makefile new file mode 100644 index 0000000..c301572 --- /dev/null +++ b/syslog/Makefile @@ -0,0 +1,14 @@ +CC = gcc +CFLAGS = -Wall -Wextra -O2 + +TARGET = main.elf +SRC = main.c + +#LDFLAGS = + +$(TARGET): $(SRC) + @echo CC $@ + @$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) + +clean: + rm -f $(TARGET) diff --git a/syslog/main.c b/syslog/main.c new file mode 100644 index 0000000..187d7be --- /dev/null +++ b/syslog/main.c @@ -0,0 +1,24 @@ +#include +#include + +/* + * For unix systems: + * tail /var/log/messages + * + * For systems using systemd: + * journalctl -t my_daemon + */ + +#define NAME "my_program" + +int main(void) { + /* LOG_PID ,LOG_CONS ,LOG_ODELAY ,LOG_NDELAY ,LOG_NOWAIT ,LOG_PERROR */ + openlog(NAME, LOG_PID | LOG_CONS, LOG_USER); + + /* LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO, LOG_DEBUG */ + syslog(LOG_INFO, "Hello, log!"); + syslog(LOG_INFO, "Formatting works %s!", "as well"); + + closelog(); + return EXIT_SUCCESS; +} diff --git a/walk.c b/walk.c new file mode 100644 index 0000000..6b20fd1 --- /dev/null +++ b/walk.c @@ -0,0 +1,70 @@ +#include +#include +#include +#include +#include + +void walk_dir(const char *path, int follow_symlinks, int ignore_hidden) { + DIR *dir = opendir(path); + if (!dir) { + perror(path); + return; + } + + struct dirent *entry; + while ((entry = readdir(dir)) != NULL) { + if (strncmp(entry->d_name, ".", 1) == 0) + continue; + + if (strncmp(entry->d_name, "..", 2) == 0) + continue; + + // Skip hidden files if requested + if (ignore_hidden && entry->d_name[0] == '.') + continue; + + char fullpath[4096]; + snprintf(fullpath, sizeof(fullpath), "%s/%s", path, entry->d_name); + + struct stat st; + int ret; + if (follow_symlinks) + ret = stat(fullpath, &st); + else + ret = lstat(fullpath, &st); + + if (ret != 0) { + /* Permission denied ends up here */ + perror(fullpath); + continue; + } + + /* There are a bunch of macros in like S_ISDIR for checking */ + printf("FILE: %s\n", fullpath); + if (S_ISDIR(st.st_mode)) { + walk_dir(fullpath, follow_symlinks, ignore_hidden); + } + } + + closedir(dir); +} + +int main(int argc, char *argv[]) { + if (argc < 2) { + fprintf(stderr, "Usage: %s [--follow-symlinks] [--ignore-hidden]\n", argv[0]); + return 1; + } + + int follow_symlinks = 0; + int ignore_hidden = 0; + + for (int i = 2; i < argc; i++) { + if (strcmp(argv[i], "--follow-symlinks") == 0) + follow_symlinks = 1; + if (strcmp(argv[i], "--ignore-hidden") == 0) + ignore_hidden = 1; + } + + walk_dir(argv[1], follow_symlinks, ignore_hidden); + return 0; +}