创建带有分隔符的解析器脚本

Question

I am trying to convert this input from file.txt

a,b;c^d"e}
f;g,h!;i8j-

into this output

a,b,c,d,e,f,g,h,i,j

with awk

The best I did so far is

awk '$1=$1' FS="[;,^}8-]" OFS="." file.txt

1. how can I escape interpritating " as a special character? " doesn`t work
2. avoid duplicate ,, in the output and delete the last ,

Answer 1

One in awk (not for all awks, tested successfully in gawk, mawk, busybox awk and Macos awk version 20200816, unsuccessfully in Debian's awk version 20121220 aka original-awk. Limitations in locales as well.)

$ awk -v RS="^$" '{      # read whole file in 
    gsub(/[^a-z]+/,",")  # replace all non lowercase alphabet substrings with a comma
    sub(/,$/,"")         # remove trailing comma
}1' file                 # output

Output:

a,b,c,d,e,f,g,h,i,j

Answer 2

Using any POSIX awk and assuming you want any non-alphabetic character to act as a field separator:

$ awk -F '[^[:alpha:]]+' -v OFS=',' '{printf "%s", p; $1=$1; p=$0} END{sub(OFS"$","",p); print p}' file
a,b,c,d,e,f,g,h,i,j

If you really do just want to use the specific set of characters in your question as the field separators then just change [^[:alpha:]]+ to [;;^}8"-]+

Answer 3

KISS :

$ grep -o '[a-z]' file | paste -sd ',' -
a,b,c,d,e,f,g,h,i,j

Should works on most GNU/Linux , even busybox & freeBSD (the - is then mandatory)

Answer 4

I would harness GNU AWK for this task following way, let file.txt content be

a,b;c^d"e} f;g,h!;i8j-

then

awk 'BEGIN{FPAT="[a-z]";OFS=","}{$1=$1;print}' file.txt

gives output

a,b,c,d,e,f,g,h,i,j

Explanation: I inform GNU AWK that field is single lowercase ASCII letter using FPAT , and output field separator ( OFS ) is , , then for each line I do $1=$1 to trigger line rebuild and print line.

(tested in GNU Awk 5.0.1)

Answer 5

If you only want to replace non-letter characters with commas and squeeze repeated commas, tr is your friend:

tr -sc '[:alpha:]' ','

Answer 6

Using gnu-sed replace 1 or more chars other than az with a comma. Then remove all leading and trailing comma's

sed -Ez 's/[^a-z]+/,/g; s/^,+|,+$//' file

Output

a,b,c,d,e,f,g,h,i,j

Answer 7

If ed is available/acceptable.

The script.ed

%s/[^a-z]/ /g
%s/[[:blank:]]\{1,\}/,/g
g/./;j\
s/,$//
,p
Q

---

Now run

ed -s file.txt < script.ed

Answer 8

 echo "${input_data}" | 

 mawk 'NF-=_==$NF' FS='[^[:alpha:]]*' OFS=, RS=

a,b,c,d,e,f,g,h,i,j

if there's possibility of leading edge seps, use this instead:

echo ']a['

 gawk 'gsub("^,|,$",_,$:(NF=NF))^_' FS='[^[:alpha,]]*' OFS=, RS=

a 

Answer 9

If you are ok with Perl solution, here is an one-liner;

perl -ne '$_ =~ s/[^[:alnum:]]//g; print join(",", split//, $_)'

which outputs:

a,b,c,d,ef,g,h,i,8,j

Simply, you are substituting characters that are not alpha-numeric with nothing.