Added isascii.

1 files changed, 141 insertions, 0 deletions

diff --git a/isascii.c b/isascii.c
new file mode 100644
index 0000000..6294c01
--- /dev/null
+++ b/isascii.c
@@ -0,0 +1,141 @@
+/*
+ * isascii - verify that input files consist of ASCII characters only
+ * Copyright (C) 2007  Lars Wirzenius <liw@iki.fi>
+ * 
+ * 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/>.
+ */
+
+
+#define _BSD_SOURCE /* For isascii(3).  */
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <getopt.h>
+
+#include <ctype.h>
+
+
+#define VERSION "1.0"
+
+
+/*
+ * Code to indicate an invalid UTF8 character.
+ */
+enum { INVALID_CHAR = 0xffffffff };
+
+
+/*
+ * Determine if the contents of an open file form a valid ASCII byte stream.
+ */
+static int is_ascii_byte_stream(FILE *file, char *filename, int quiet) {
+        int c;
+	unsigned long line, col;
+
+        line = 1;
+        col = 1;
+                
+        for (;;) {
+                c = getc(file);
+    
+                if (c == EOF)
+                        break;
+                else if (c == '\n') {
+                        ++line;
+                        col = 1;
+                } else if (isascii(c)) {
+                        ++col;
+                } else
+                        goto error;
+        }
+
+	return 1;
+	
+error:
+	if (!quiet) {
+		printf("%s: line %lu, char %lu: invalid ASCII code: 0x%02x\n", 
+		       filename, line, col, c);
+	}
+	return 0;
+}
+
+
+static void usage(const char *program_name) {
+	printf("Usage: %s [-hq] [--help] [--quiet] [file ...]\n", 
+	       program_name);
+	printf("Check whether input files are valid ASCII.\n");
+	printf("This is version %s.\n", VERSION);
+}
+
+
+int main(int argc, char **argv) {
+	int i, ok;
+	FILE *file;
+
+	int quiet;
+	struct option options[] = {
+		{ "help", no_argument, NULL, 'h' },
+		{ "quiet", no_argument, &quiet, 1 },
+	};
+	int opt;
+	
+	quiet = 0;
+	
+	while ((opt = getopt_long(argc, argv, "hq", options, NULL)) != -1) {
+		switch (opt) {
+		case 0:
+			break;
+			
+		case 'h':
+			usage(argv[0]);
+			exit(0);
+			break;
+			
+		case 'q':
+			quiet = 1;
+			break;
+
+		case '?':
+			exit(EXIT_FAILURE);
+
+		default:
+			abort();
+		}
+	}
+
+	if (optind == argc)
+		ok = is_ascii_byte_stream(stdin, "stdin", quiet);
+	else {
+		ok = 1;
+		for (i = optind; i < argc; ++i) {
+			file = fopen(argv[i], "r");
+			if (file == NULL) {
+				fprintf(stderr, "isascii: %s: error %d: %s\n",
+				                argv[i], errno, 
+				                strerror(errno));
+				ok = 0;
+			} else {
+			        if (!is_ascii_byte_stream(file, argv[i], quiet))
+    			                ok = 0;
+				(void) fclose(file);
+			}
+		}
+	}
+	
+	if (ok)
+		exit(0);
+	exit(EXIT_FAILURE);
+}