encoder < file1 | decoder > file2 ; cmp file1 file2sometimes I get a match and sometimes no match. Anyone see what is going wrong?
RS: Could it be that base64 puts 6 bits into one byte, so for some files the length is not divisible both by 6 and 8? (I mean, some bits are finally left over, and are maybe padded into a blank or so?)AK: The encode command auto-pads its output with '=' for input lengths not 0 modulo 3, and the decode command recognizes such padding and strips it properly. IMHO an example of input exhibiting the problem should be provided, without debugging is like walking through fog.
APN Note that 8.6 has a binary encode/decode base64 built-in commands [1].
#! /usr/tcl84/bin/tclsh
package require base64
# Purpose: read stdin or a file on the argument line and output to stdout
# a base64 encoding of the file.
# Version 1.0 by [Larry W. Virden]
# Version 1.1 by [Larry W. Virden] and [Andreas Kupries]
if { $argc > 0 } {
set fin [open [lindex $argv 0] "r"]
} else {
set fin stdin
}
fconfigure $fin -encoding binary
while { ! [eof $fin] } {
set input [read $fin 72]
puts [::base64::encode $input]
}
close $finLGT: I added "-maxlen 96" to produce a cleaner output (96 = 72 * 4 / 3)
puts [::base64::encode -maxlen 96 $input] #! /usr/tcl84/bin/tclsh
package require base64
# Purpose: read stdin or a file on the argument line and output to stdout
# a base64 decoding of the file.
# Version 1.0 by [Larry W. Virden]
# Version 1.1 by [Larry W. Virden] and [Andreas Kupries]
if { $argc > 0 } {
set fin [open [lindex $argv 0] "r"]
} else {
set fin stdin
}
fconfigure stdout -encoding binary
while { ! [eof $fin] } {
set input [gets $fin]
puts -nonewline stdout [::base64::decode $input]
}
close $fin
----
# CL wonders why they're decoding an extra null string (eof ...).
----RS agrees - using the canonical line reader code is simpler anyway: while {[gets $fin input] >= 0} {
puts -nonewline stdout [::base64::decode $input]
}