1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
|
# Date: Sun, 28 May 2006 11:20:58 +0200
# From: Frantisek Hanzlik <franta@hanzlici.cz>
# Subject: sub() function do'nt alter string length in awk 3.1.5
# To: bug-gawk@gnu.org
# Message-id: <44796B7A.3050908@hanzlici.cz>
#
# Hello,
# I not know when it is my mistake or gawk bug - in simple example below
# I delete some chars from string variable, and after this string is
# modified, but its length is unchanged.
#
# awk 'BEGIN{A="1234567890abcdef";
# for (i=1;i<6;i++){print length(A),"A=" A ".";sub("....","",A)}
# }'
# 16 A=1234567890abcdef.
# 16 A=567890abcdef.
# 16 A=90abcdef.
# 16 A=cdef.
# 16 A=.
#
# When I use gensub() instead of sub(), result is as I expected:
#
# awk 'BEGIN{A="1234567890abcdef";
# for (i=1;i<6;i++){print length(A),"A=" A ".";A=gensub("....","",1,A)}
# }'
# 16 A=1234567890abcdef.
# 12 A=567890abcdef.
# 8 A=90abcdef.
# 4 A=cdef.
# 0 A=.
#
# OS/GAWK versions:
# - GNU/Linux kernel 2.6.16-1.2122_FC5 #1 i686, Fedora Core 5 distro
# - glibc-2.4-8
# - GNU Awk 3.1.5
#
# Yours sincerely
# Frantisek Hanzlík
#
# == Lucní 502 Linux/Unix, Novell, Internet Tel: +420-373729699 ==
# == 33209 Stenovice e-mail:franta@hanzlici.cz Fax: +420-373729699 ==
# == Czech Republic http://hanzlici.cz/ GSM: +420-604117319 ==
#
#
#
# #####################################################################################
# This Mail Was Scanned by 012.net AntiVirus Service3- Powered by TrendMicro Interscan
#
BEGIN{A="1234567890abcdef";
for (i=1;i<6;i++){print length(A),"A=" A ".";sub("....","",A)}
}
BEGIN{A="1234567890abcdef";
for (i=1;i<6;i++){print length(A),"A=" A ".";A=gensub("....","",1,A)}
}
|
