clean up code

1 files changed, 72 insertions, 51 deletions

diff --git a/uuencode.c b/uuencode.c
index 9b1965c..066e992 100644
--- a/uuencode.c
+++ b/uuencode.c
@@ -23,7 +23,10 @@
  */
 
 #define _XOPEN_SOURCE 700
+#include <errno.h>
+#include <locale.h>
 #include <stdio.h>
+#include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -31,83 +34,101 @@
 static const char *b64s =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 
-static int encode(FILE * in, char *out, int mode, int b64)
+static inline int encodechunk(char *in, char *out, int n, int b64)
 {
-	char bin[3], bout[76];
-	int nread = 0, lread = 0, lpos = 0;
-	int linelength = b64 ? 54 : 43;
-	int i;
-
-	printf("begin%s %03o %s\n", b64 ? "-base64" : "", mode, out);
-
-	while (!feof(in)) {
-		nread = fread(bin, sizeof(char), 3, in);
-		if (nread > 0) {
-			bout[lpos++] = (bin[0] >> 2) & 0x3f;
-			bout[lpos++] =
-			    ((bin[0] << 4) | ((bin[1] >> 4) & 0xf)) & 0x3f;
-			bout[lpos++] =
-			    ((bin[1] << 2) | ((bin[2] >> 6) & 0x3)) & 0x3f;
-			bout[lpos++] = (bin[2]) & 0x3f;
-			bin[0] = bin[1] = bin[2] = 0;
-			lread += nread;
+	out[0] = (in[0] >> 2) & 0x3f;
+	out[1] = ((in[0] << 4) | ((in[1] >> 4) & 0xf)) & 0x3f;
+	out[2] = ((in[1] << 2) | ((in[2] >> 6) & 0x3)) & 0x3f;
+	out[3] = (in[2]) & 0x3f;
+
+	for (int i = 0; i < 4; i++) {
+		out[i] = b64 ? b64s[(int)(out[i])] : out[i] + 0x20;
+	}
+
+	if (n < 2) {
+		out[2] = b64 ? '=' : ((in[0] << 4) & 0x3f) + 0x20;
+	}
+
+	if (n < 3) {
+		out[3] = b64 ? '=' : ((in[1] << 2) & 0x3f) + 0x20;
+	}
+
+	return b64 ? 4 : 4 - (3-n);
+}
+
+static int encode(FILE * in, const char *path, mode_t mode, int b64)
+{
+	printf("begin%s %03o %s\n", b64 ? "-base64" : "", mode, path);
+
+	int lpos = 0;
+	int linelength = b64 ? 75 : 43;
+
+	int nread = 0;
+	char ibuf[3] = {0};
+	char obuf[76] = {0};
+
+	while ((nread = fread(ibuf, 1, sizeof(ibuf), in)) != 0) {
+		if (nread < 0) {
+			perror("uuencode");
+			return 1;
 		}
 
-		if (feof(in) || nread == 0 || lread > linelength) {
-			for (i = 0; i < lpos; i++)
-				bout[i] = b64 ? b64s[bout[i]] : bout[i] + 0x20;
+		lpos += encodechunk(ibuf, obuf + lpos, nread, b64);
 
-			if (b64) {
-				if (nread == 1)
-					bout[lpos - 2] = '=';
-				if (nread == 1 || nread == 2)
-					bout[lpos - 1] = '=';
+		if (lpos > linelength || nread < 3) {
+			if (!b64) {
+				fputc(0x20 + lpos, stdout);
 			}
 
-			if (!b64)
-				putchar(0x20 + lread);
-			fwrite(bout, sizeof(char), lpos, stdout);
+			fwrite(obuf, 1, lpos, stdout);
 			fputc('\n', stdout);
-			lread = 0;
 			lpos = 0;
+			memset(obuf, 0, sizeof(obuf));
 		}
+		memset(ibuf, 0, sizeof(ibuf));
 	}
 
-	if (b64)
-		printf("====\n");
-	else
-		printf("%c\nend\n", 0x20);
-
+	printf("%s\n", b64 ? "====" : "end");
 	return 0;
 }
 
 int main(int argc, char *argv[])
 {
-	int b64 = 0, mode = 0644, c;
-	FILE *input;
-	struct stat st;
+	int mime_base64 = 0;
+	mode_t mode = 0644;
+	FILE *input = stdin;
+	int c;
+
+	setlocale(LC_ALL, "");
 
-	while ((c = getopt(argc, argv, ":m")) != -1) {
+	while ((c = getopt(argc, argv, "m")) != -1) {
 		switch (c) {
 		case 'm':
-			b64 = 1;
+			mime_base64 = 1;
 			break;
+
 		default:
 			return 1;
 		}
 	}
 
-	if (argc - optind == 2) {
-		input = fopen(argv[optind++], "r");
-		if (fstat(fileno(input), &st) == 0)
-			mode = st.st_mode & 0777;
-	} else if (argc - optind == 1)
-		input = stdin;
-	else
+	if (optind > argc) {
+		fprintf(stderr, "uuencode: missing operand\n");
 		return 1;
+	}
 
-	if (input == NULL)
-		return 1;	// File I/O error
+	if (argc - optind == 2) {
+		input = fopen(argv[optind], "r");
+		if (input == NULL) {
+			fprintf(stderr, "uuencode: %s: %s\n", argv[optind], strerror(errno));
+			return 1;
+		}
+
+		struct stat st;
+		if (fstat(fileno(input), &st) == 0) {
+			mode = st.st_mode & 0777;
+		}
+	}
 
-	return encode(input, argv[optind], mode, b64);
+	return encode(input, argv[argc - 1], mode, mime_base64);
 }