Added uniq (most options not handled)

1 files changed, 135 insertions, 0 deletions

diff --git a/src/uniq.c b/src/uniq.c
new file mode 100644
index 0000000..a769b99
--- /dev/null
+++ b/src/uniq.c
@@ -0,0 +1,135 @@
+#define _POSIX_C_SOURCE 200809L
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <string.h>
+#include <strings.h>
+#include <errno.h>
+
+static char *g_name = "uniq";
+
+void fatal(const char *format, ...)
+{
+	va_list	ap;
+
+	va_start(ap, format);
+	fprintf(stderr, "%s: ", g_name);
+	vfprintf(stderr, format, ap);
+	fputc('\n', stderr);
+	va_end(ap);
+	exit(EXIT_FAILURE);
+}
+
+char *xstrdup(const char *s)
+{
+	char *ret = strdup(s);
+	if (ret == NULL)
+		fatal("%s", strerror(errno));
+	return ret;
+}
+
+long parse_ulong(char *str, char *error_msg)
+{
+	char *end;
+	long ret;
+
+	errno = 0;
+	ret = strtol(str, &end, 10);
+	if (errno != 0 || ret < 0 || *end != '\0')
+		fatal("%s: %s", optarg, error_msg);
+	return ret;
+}
+
+enum flags
+{
+	FLAG_COUNT        = 1 << 0,
+	FLAG_REPEATED     = 1 << 1,
+	FLAG_REPEATED_ALL = 1 << 2,
+	FLAG_IGNORE_CASE  = 1 << 3,
+	FLAG_UNIQUE_ONLY  = 1 << 4,
+};
+
+bool line_equal(char *line1, char *line2, enum flags flags)
+{
+	if (flags & FLAG_IGNORE_CASE)
+		return (strcasecmp(line1, line2) == 0);
+	return (strcmp(line1, line2) == 0);
+}
+
+void line_print(char *line, enum flags flags, FILE *output, int counter)
+{
+	if (flags & FLAG_COUNT)
+		fprintf(output, "%7u ", counter);
+	fputs(line, output);
+}
+
+int main(int argc, char **argv)
+{
+	int        option;
+	enum flags flags       = 0;
+	long       skip_fields = -1;
+	long       skip_chars  = -1;
+	long       width       = -1;
+	char       delimiter   = '\n';
+
+	while ((option = getopt(argc, argv, "cdDf:is:uzw:")) != -1)
+	{
+		switch (option)
+		{
+			case 'c': flags |= FLAG_COUNT;        break;
+			case 'd': flags |= FLAG_REPEATED;     break;
+			case 'D': flags |= FLAG_REPEATED_ALL; break;
+			case 'i': flags |= FLAG_IGNORE_CASE;  break;
+			case 'u': flags |= FLAG_UNIQUE_ONLY;  break;
+			case 'z': delimiter = '\0';           break;
+
+			case 'f': skip_fields = parse_ulong(optarg, "invalid number of fields to skip");    break;
+			case 's': skip_chars  = parse_ulong(optarg, "invalid number of bytes to skip");     break;
+			case 'w': width       = parse_ulong(optarg, "invalid number of bytes to compare");  break;
+		}
+	}
+
+	FILE *input  = stdin;
+	FILE *output = stdout;
+
+	if (argc - optind > 2)
+		fatal("extra operand '%s'", argv[optind + 2]);
+	if (optind < argc)
+	{
+		input = fopen(argv[optind], "r");
+		if (input == NULL)
+			fatal("%s: %s", argv[optind], strerror(errno));
+		if (optind + 1 < argc)
+		{
+			output = fopen(argv[optind + 1], "w");
+			if (output == NULL)
+				fatal("%s: %s", argv[optind + 1], strerror(errno));
+		}
+	}
+
+	char   *line_prev = NULL;
+	char   *line      = NULL;
+	size_t line_size  = 0;
+	size_t counter    = 1;
+
+	if (getdelim(&line_prev, &line_size, delimiter, input) == -1)
+		return EXIT_SUCCESS;
+	while (getdelim(&line, &line_size, delimiter, input) != -1)
+	{
+		if (line_equal(line, line_prev, flags))
+		{
+			counter++;
+		}
+		else
+		{
+			line_print(line_prev, flags, output, counter);
+			counter = 1;
+			free(line_prev);
+			line_prev = xstrdup(line);
+		}
+	}
+	line_print(line_prev, flags, output, counter);
+	return EXIT_SUCCESS;
+}