diff options
Diffstat (limited to 'cut')
| -rw-r--r-- | cut/cut.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/cut/cut.c b/cut/cut.c new file mode 100644 index 0000000..2a7990d --- /dev/null +++ b/cut/cut.c @@ -0,0 +1,225 @@ +#define _POSIX_C_SOURCE 200809L +#define _DEFAULT_SOURCE 1 + +#include <unistd.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <ctype.h> +#include <stdbool.h> +#include <errno.h> + +#define LIST_VALUE_INFINITY -1 +#define LIST_VALUE_SINGLETON -2 + +#define LINE_BUFFER_SIZE 2024 + +typedef enum +{ + LIST_BYTE, + LIST_CHAR, + LIST_FIELD, + LIST_UNDEFINED, +} t_list_type; + +char *g_name = "cut"; + +void fatal_msg(char *message) +{ + fprintf(stderr, "%s: %s\n", g_name, message); + exit(EXIT_FAILURE); +} + +void fatal_errno(void) +{ + perror(g_name); + exit(EXIT_FAILURE); +} + +int parse_uint(char *s, char **endptr) +{ + if (!isdigit(*s)) + return -1; + unsigned long x = strtoul(s, endptr, 10); + return (int)x; +} + +int main(int argc, char **argv) +{ + int option; + int list_start = LIST_VALUE_INFINITY; + int list_end = LIST_VALUE_INFINITY; + t_list_type list_type = LIST_UNDEFINED; + wchar_t delimiter = '\t'; + bool print_only_delimiter = false; + char line_delimiter = '\n'; + + g_name = argv[0]; + while ((option = getopt(argc, argv, "b:c:d:f:sz")) > 0) + { + + switch (option) + { + case 'b': + case 'c': + case 'f': + if (list_type != LIST_UNDEFINED) + fatal_msg("only one type of list may be specified"); + + switch (option) + { + case 'b': list_type = LIST_BYTE; break; + case 'c': list_type = LIST_CHAR; break; + case 'f': list_type = LIST_FIELD; break; + } + + char *ptr = optarg; + + char *hyphen = strchr(ptr, '-'); + if (hyphen == NULL) // N + { + list_start = parse_uint(ptr, &ptr); + if (*ptr != '\0') + fatal_msg(""); + list_end = LIST_VALUE_SINGLETON; + } + else + { + if (ptr == hyphen) // -M + { + list_end = parse_uint(ptr + 1, &ptr); + printf(">> %d %d |%s|\n", list_start, list_end, ptr); + if (*ptr != '\0') + fatal_msg(""); + } + else + { + list_start = parse_uint(ptr, &ptr); + if (*ptr != '-') + fatal_msg(""); + ptr++; + if (*ptr != '\0') // N-M + { + list_end = parse_uint(ptr, &ptr); + } + if (*ptr != '\0') + fatal_msg(""); + } + } + break; + + case 'd': + delimiter = optarg[0]; + if (delimiter != '\0' && optarg[1] != '\0') + fatal_msg("the delimiter must be a single character"); + break; + + case 's': + print_only_delimiter = true; + break; + case 'z': + line_delimiter = '\0'; + break; + } + } + if (list_type == LIST_UNDEFINED) + fatal_msg("you must specify a list of bytes, characters, or fields"); + if (list_type != LIST_FIELD && delimiter != '\t') + fatal_msg("an input delimiter may be specified only when operating on fields"); + if (list_type != LIST_FIELD && print_only_delimiter) + fatal_msg("suppressing non-delimited lines makes sense only when operating on fields"); + + if (list_start == 0) + fatal_msg("list are numbered from 1"); + if (list_end > 0 && list_start > list_end) + fatal_msg("invalid decreasing range"); + + char *line = NULL; + size_t line_buffer_size = LINE_BUFFER_SIZE; + ssize_t read_size = -1; + + if ((line = malloc(LINE_BUFFER_SIZE)) == NULL) + exit(1); + + char *field; + int counter = 1; + char delimiter_buf[2] = {delimiter, '\0'}; + + if (optarg == NULL) + { + errno = 0; + while ((read_size = getdelim(&line, &line_buffer_size, line_delimiter, stdin)) > 0) + { + switch (list_type) + { + case LIST_BYTE: + case LIST_CHAR: // TODO unicode + if (list_end == LIST_VALUE_SINGLETON) + { + if (read_size - 1 >= list_start) + fputc(line[list_start - 1], stdout); + } + else if (list_start == LIST_VALUE_INFINITY) + { + line[list_end] = '\0'; + fputs(line, stdout); + } + else if (list_end == LIST_VALUE_INFINITY) + { + fputs(&line[list_start - 1], stdout); + } + else + { + line[list_end] = '\0'; + fputs(&line[list_start - 1], stdout); + } + break; + case LIST_FIELD: + while ((field = strsep(&line, delimiter_buf)) != NULL) + { + if (list_end == LIST_VALUE_SINGLETON && counter == list_start) + fputs(field, stdout); + else if (list_start == LIST_VALUE_INFINITY && counter <= list_end) + fputs(field, stdout); + else if (list_end == LIST_VALUE_INFINITY && counter >= list_start) + fputs(field, stdout); + else if (counter >= list_start && counter <= list_end) + fputs(field, stdout); + counter++; + } + break; + } + putchar('\n'); + } + free(line); + if (errno != 0) + fatal_errno(); + return EXIT_SUCCESS; + } + + + /* while (optarg != NULL) */ + /* { */ + /* if (strcmp(optarg, "-") == 0) */ + /* { */ + /* // read stdin */ + /* } */ + /* else */ + /* { */ + /* FILE *file; */ + /* */ + /* if ((file = fopen(optarg, "r")) == NULL) */ + /* fatal_errno(); */ + /* */ + /* while (getdelim(&line, 0, line_delimiter, file)) */ + /* { */ + /* if (field) */ + /* strsep(line, delimiter); */ + /* } */ + /* } */ + /* } */ + + + + return EXIT_SUCCESS; +} |