sed: -e expression #1, char 0: no previous regular expression Post: 302688727

Sponsored Content

Top Forums UNIX for Advanced & Expert Users sed: -e expression #1, char 0: no previous regular expression Post 302688727 by RudiC on Monday 20th of August 2012 04:53:00 AM

08-20-2012

Registered User

Quote:

Originally Posted by Don Cragun

You haven't said what shell you're using, but at least with bash and ksh, setting an array with:

Code:

array=(a b c)

sets ${array[1]} to a, ${array[2]} to b, and ${array[3]} to c. It doesn't set ${array[0]} so your first call to sed

Code:

sed  -n "/${problem_arr[0]}/,/${problem_arr[1]}/p" problemid.txt

expands to:

Code:

sed  -n "//,/PRS111/p" problemid.txt

and since your first RE is //, it is trying to search for the previously used RE (but there is no previously used RE in this invocation of sed.

Sorry, disagree. From the bash man page:

Quote:

Arrays are assigned to using compound assignments of the form name=(value1 ... valuen), where each value is of the form [sub- script]=string. Indexed array assignments do not require the bracket and subscript. When assigning to indexed arrays, if the optional brackets and subscript are supplied, that index is assigned to; other- wise the index of the element assigned is the last index assigned to by the statement plus one. Indexing starts at zero.

Running InduInduIndu's code snippet - using ${#...} to correctly get the member count - fails in the fourth loop,

Code:

++ k=4
++ sed -n //,//p problemid.txt
sed: -e expression #1, char 0: no previous regular expression

indicating that he should limit his loop count to 0 - 2. The first loop works fine:

Code:

++ sed -n /PRS111/,/PRS213/p problemid.txt

RudiC

View Public Profile for RudiC

Find all posts by RudiC

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Regular expression with sed

Hi, I'm trying following:echo "test line XA24433 test" | sed 's/.*X$.*$/X\1/' XA24433 test While I want the output as: XA24433 I want to grab the words starting with letter X till the next space, this word can be anywhere in the line.

2. Shell Programming and Scripting

Regular expression with SED

Hi! I'm trying to write a regexp but I have no luck... I have a string like this: param1=sometext&param2=hello&param3=bye Also, the string can be simply: param2=hello I want to return the value of param2: "hello". How can I do this? Thanks.

3. Shell Programming and Scripting

Regular expression (sed)

Hi I need to get text that are within "" For example File: asdasd "test test2" sadasds asdda asdasd "demo demo2" Output: test test2 demo demo2 Any help is good Thank you

4. Shell Programming and Scripting

sed regular expression help

please consider this: echo "11111*X*005010X279~ST*270*1111111*005010X279~BHT*0011*11" | sed 's/.*$005010X(\d)(\d)(\d)*$.*$/\1/'i'm searching for first occurrence of 005010X while leaving rest of characters out. :confused: any tips? thnx in advance guys.

5. Shell Programming and Scripting

Integer expression expected: with regular expression

CA_RELEASE has a value of 6. I need to check if that this is a numeric value. if not error. source $CA_VERSION_DATA if * ] then echo "CA_RELESE $CA_RELEASE is invalid" exit -1 fi + source /etc/ncgl/ca_version_data ++ CA_PRODUCT_ID=samxts ++ CA_RELEASE=6 ++ CA_WEEK_NO=7 ++...

6. UNIX for Dummies Questions & Answers

Regular Expression In Sed

Hi , I am learing sed echo abc 123 def 456 | sed 's|$*$ $*$|\1|' is returning abc def 456 i was hoping abc def "\1" should only print the occurence of the first pattern but according to my understanding it is just removing the first occurence of the second pattern...

7. Shell Programming and Scripting

sed: -e expression #1, char 21: unterminated `s' command

I have read many threads, but I still didn't find the right answer. May be i didn't find the right thread, though are so many threads for the same question. Basically the situation is - find date in a file and replace it with another date. (its not homework, its part of lot of a big processing,...

8. Programming

Perl: How to read from a file, do regular expression and then replace the found regular expression

Hi all, How am I read a file, find the match regular expression and overwrite to the same files. open DESTINATION_FILE, "<tmptravl.dat" or die "tmptravl.dat"; open NEW_DESTINATION_FILE, ">new_tmptravl.dat" or die "new_tmptravl.dat"; while (<DESTINATION_FILE>) { # print...

9. Shell Programming and Scripting

sed regular expression

Hi , I need to remove pipe character from a |^ delimeted file. Something like |^tran|sformers||^|revenge |of fallen|^ to |^transformers|^revenge of fallen|^... Cold anybody please help to build the regular expression using sed . many thanks. Please use code tags next time for...

LEARN ABOUT BSD

re_comp

REGEX(3)						     Library Functions Manual							  REGEX(3)

NAME

       re_comp, re_exec - regular expression handler

SYNOPSIS

       char *re_comp(s)
       char *s;

       re_exec(s)
       char *s;

DESCRIPTION

       Re_comp	compiles a string into an internal form suitable for pattern matching.	Re_exec checks the argument string against the last string
       passed to re_comp.

       Re_comp returns 0 if the string s was compiled successfully; otherwise a string containing an error message  is	returned.  If  re_comp	is
       passed 0 or a null string, it returns without changing the currently compiled regular expression.

       Re_exec returns 1 if the string s matches the last compiled regular expression, 0 if the string s failed to match the last compiled regular
       expression, and -1 if the compiled regular expression was invalid (indicating an internal error).

       The strings passed to both re_comp and re_exec may have trailing or embedded newline characters; they are terminated by nulls.  The regular
       expressions recognized are described in the manual entry for ed(1), given the above difference.

SEE ALSO

       ed(1), ex(1), egrep(1), fgrep(1), grep(1)

DIAGNOSTICS

       Re_exec returns -1 for an internal error.

       Re_comp returns one of the following strings if an error occurs:

	    No previous regular expression,
	    Regular expression too long,
	    unmatched (,
	    missing ],
	    too many () pairs,
	    unmatched ).

3rd Berkeley Distribution					   May 15, 1985 							  REGEX(3)

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Regular expression with sed

Discussion started by: nervous

2. Shell Programming and Scripting

Regular expression with SED

Discussion started by: GagleKas

3. Shell Programming and Scripting

Regular expression (sed)

Discussion started by: blito_loco

4. Shell Programming and Scripting

sed regular expression help

Discussion started by: grep01

5. Shell Programming and Scripting

Integer expression expected: with regular expression

Discussion started by: ketkee1985

6. UNIX for Dummies Questions & Answers

Regular Expression In Sed

Discussion started by: max_hammer

7. Shell Programming and Scripting

sed: -e expression #1, char 21: unterminated `s' command

Discussion started by: avinthm

8. Programming

Perl: How to read from a file, do regular expression and then replace the found regular expression

Discussion started by: jessy83

9. Shell Programming and Scripting

sed regular expression

Discussion started by: kokjek

LEARN ABOUT BSD

re_comp