utils-std

commit: 7a35d61357d0e10ded9ed30db1ab0711d265fca1
parent 7e734462c1628962c49dd20457b5f75473926584
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date:   Wed,  1 Nov 2023 11:45:49 +0100

cmd/base64: Add -w option

Diffstat:
M
cmd/base64.1
8
++++++++
M
cmd/base64.c
56
+++++++++++++++++++++++++++++++++-----------------------

2 files changed, 41 insertions(+), 23 deletions(-)
diff --git a/cmd/base64.1 b/cmd/base64.1
@@ -10,6 +10,7 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl d
+.Op Fl w Ar wrap
 .Op Ar file ...
 .Sh DESCRIPTION
 .Nm
@@ -25,6 +26,13 @@ reads from the standard input.
 .Bl -tag -width Ds
 .It Fl d
 Decode input instead of encoding it.
+.It Fl w Ar wrap
+Write at most
+.Ar wrap
+characters per line.
+If
+.Ar wrap
+is 0, then no newlines are written.
 .El
 .Sh EXIT STATUS
 .Ex -std
diff --git a/cmd/base64.c b/cmd/base64.c
@@ -17,8 +17,20 @@
 // 64(26+26+10+2)
 static char b64_encmap[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 static size_t c_out        = 0;
-// TODO: -w option ; 76 is lowest of all base64 related RFCs
-static size_t wrap_nl = 76;
+// 76 is lowest of all base64 related RFCs
+static long wrap_nl = 76;
+
+static int
+xputc(int c, FILE *stream)
+{
+	if(fputc(c, stream) == EOF)
+	{
+		fprintf(stderr, "base64: Error writing: %s\n", strerror(errno));
+		return 1;
+	}
+
+	return 0;
+}
 
 static inline uint8_t
 b64_get(uint8_t pos)
@@ -78,21 +90,17 @@ encode(FILE *fin, const char *name)
 			obuf[4 - pad] = '=';
 		}
 
-		if(write(1, (char *)obuf, 4) != 4)
+		if(fwrite((char *)obuf, 4, 1, stdout) != 1)
 		{
 			fprintf(stderr, "base64: Error writing: %s\n", strerror(errno));
 			return 1;
 		}
 		c_out += 4;
 
-		if(wrap_nl != 0 && c_out >= wrap_nl)
+		if(wrap_nl != 0 && (c_out + 4) > wrap_nl)
 		{
 			c_out = 0;
-			if(write(1, "\n", 1) != 1)
-			{
-				fprintf(stderr, "base64: Error writing: %s\n", strerror(errno));
-				return 1;
-			}
+			if(xputc('\n', stdout) != 0) return 1;
 		}
 
 		if(feof(fin)) return 0;
@@ -101,18 +109,6 @@ encode(FILE *fin, const char *name)
 	abort(); // unreachable
 }
 
-static int
-xputc(int c, FILE *stream)
-{
-	if(fputc(c, stream) == EOF)
-	{
-		fprintf(stderr, "base64: Error writing: %s\n", strerror(errno));
-		return 1;
-	}
-
-	return 0;
-}
-
 // This function is based on NetBSD's code, which contains the following notices:
 // Copyright (c) 2018 The NetBSD Foundation, Inc.
 //
@@ -216,13 +212,27 @@ main(int argc, char *argv[])
 
 	int c = 0, ret = 0;
 
-	while((c = getopt(argc, argv, ":d")) != -1)
+	while((c = getopt(argc, argv, ":dw:")) != -1)
 	{
 		switch(c)
 		{
 		case 'd':
 			process = &decode;
 			break;
+		case 'w':
+			errno   = 0;
+			char *e = "";
+			wrap_nl = strtol(optarg, &e, 10);
+
+			// extraneous characters is invalid
+			if(*e != 0) errno = EINVAL;
+
+			if(errno != 0)
+			{
+				fprintf(stderr, "base64: Option `-w %s`: %s\n", optarg, strerror(errno));
+				return 1;
+			}
+			break;
 		case ':':
 			fprintf(stderr, "base64: Error: Missing operand for option: ‘-%c’\n", optopt);
 			return 1;
@@ -281,7 +291,7 @@ main(int argc, char *argv[])
 	}
 
 end:
-	if(c_out > 0)
+	if(wrap_nl != 0 && c_out > 0)
 	{
 		printf("\n");
 	}