Repeat: you need to double the backslashes if you use double quotes. This is an artefact of the shell's quoting mechanisms, not of sed syntax as such. If you use the slash as separator, you do need to backslash any slashes which are not separators; but it's better to simply use a different separator character.
With single quotes, that becomes
The variables $name or $answer obviously cannot contain the separator character in their values (or you need to escape the values).
Last edited by era; 10-08-2008 at 03:15 AM..
Reason: Need to escape variables if they contain the separator
is it possible to escape the \ character in sed?
right now I'm trying to replace all occurances of \ with \\
sed \"s|test|test_replacement|g\" file1 > output; #this works fine
sed \"s|\\|\\\|g\" file1 > output; #this generates the following error:
sed: -e expression #1, char 17:... (1 Reply)
I want to replace a string which contains "/" in vi but what is the escape character for forward slash?
e.g. I have a text file with the contents below and I want to replace "/Top/Sub/Sub1" with "ABC".
/Top/Sub/Sub1
The replace command I am using is ... (4 Replies)
Hi ,
I want to change space to ' in my script.
I tried doing this,
sed 's/ /\'/g' filename
but i could not get it.
can some one help me please.
Thanks,
Deepak (4 Replies)
Hello experts
I am trying to write a shell script which will add ' ' to a unix variable and then pass it to oracle for inserting to a table.
I am running the script as root and I have to do a su -c .
The problem is the character ' is not recognised inside sed even after adding escape... (1 Reply)
my @array;
my $sepa = "|";
print $sepa;
open FH, "<100_20091023_2.txt";
while(<FH>){
push @array, split(/\$sepa/, $_);
print "@array\n\n";
}
I am not able split the line which have | separated (1 Reply)
Hi all,
I've got a problem with sed. Want to use it to add escape character \ before $ and ' symbols so
condition='1'$some will become condition=\'1\'\$some
echo "condition='1'$some" | sed 's/\($\)/\\\1/g'
is not working properly. Can somebody help me with this please?
Regards,... (7 Replies)
Good afternoon all,
I'm hoping my newbie question can help bolster someone's street_cred.sh today.
I'm trying to "fingerprint" SQL on its way into the rdbms for a benchmarking process (so I can tie the resource allocation back to the process more precisely).
To do this, I'm essentially... (4 Replies)
i have string as below
str=".<date>"
in which i need to replace < with /< , when i tried with sed , got the output.
--> echo $str | sed 's/</\\</g'
.\<date>
when i tried to assign it to a variable , i am not getting the same
--> a=`echo $str | sed 's/</\\</g'` ; echo $a... (4 Replies)
Hi ,
I am looking for a function which will do the following.
1. I have a variable which will hold few special chracter like
SPECIAL_CHARS="& ;"2. I have an escape character.
ESCAPE_CHAR="\"3. Now when I passed some string in the function it will return the same string but now it will... (8 Replies)
Discussion started by: Anupam_Halder
8 Replies
LEARN ABOUT PHP
regex
regex(1F) FMLI Commands regex(1F)NAME
regex - match patterns against a string
SYNOPSIS
regex [-e] [ -v "string"] [ pattern template] ... pattern [template]
DESCRIPTION
The regex command takes a string from the standard input, and a list of pattern / template pairs, and runs regex() to compare the string
against each pattern until there is a match. When a match occurs, regex writes the corresponding template to the standard output and
returns TRUE. The last (or only) pattern does not need a template. If that is the pattern that matches the string, the function simply
returns TRUE. If no match is found, regex returns FALSE.
The argument pattern is a regular expression of the form described in regex(). In most cases, pattern should be enclosed in single quotes
to turn off special meanings of characters. Note that only the final pattern in the list may lack a template.
The argument template may contain the strings $m0 through $m9, which will be expanded to the part of pattern enclosed in ( ... )$0 through
( ... )$9 constructs (see examples below). Note that if you use this feature, you must be sure to enclose template in single quotes so
that FMLI does not expand $m0 through $m9 at parse time. This feature gives regex much of the power of cut(1), paste(1), and grep(1), and
some of the capabilities of sed(1). If there is no template, the default is $m0$m1$m2$m3$m4$m5$m6$m7$m8$m9.
OPTIONS
The following options are supported:
-e Evaluates the corresponding template and writes the result to the standard output.
-v "string" Uses string instead of the standard input to match against patterns.
EXAMPLES
Example 1: Cutting letters out of a string
To cut the 4th through 8th letters out of a string (this example will output strin and return TRUE):
`regex -v "my string is nice" '^.{3}(.{5})$0' '$m0'`
Example 2: Validating input in a form
In a form, to validate input to field 5 as an integer:
valid=`regex -v "$F5" '^[0-9]+$'`
Example 3: Translating an environment variable in a form
In a form, to translate an environment variable which contains one of the numbers 1, 2, 3, 4, 5 to the letters a, b, c, d, e:
value=`regex -v "$VAR1" 1 a 2 b 3 c 4 d 5 e '.*' 'Error'`
Note the use of the pattern '.*' to mean "anything else".
Example 4: Using backquoted expressions
In the example below, all three lines constitute a single backquoted expression. This expression, by itself, could be put in a menu defini-
tion file. Since backquoted expressions are expanded as they are parsed, and output from a backquoted expression (the cat command, in this
example) becomes part of the definition file being parsed, this expression would read /etc/passwd and make a dynamic menu of all the login
ids on the system.
`cat /etc/passwd | regex '^([^:]*)$0.*$' '
name=$m0
action=`message "$m0 is a user"`'`
DIAGNOSTICS
If none of the patterns match, regex returns FALSE, otherwise TRUE.
NOTES
Patterns and templates must often be enclosed in single quotes to turn off the special meanings of characters. Especially if you use the
$m0 through $m9 variables in the template, since FMLI will expand the variables (usually to "") before regex even sees them.
Single characters in character classes (inside []) must be listed before character ranges, otherwise they will not be recognized. For exam-
ple, [a-zA-Z_/] will not find underscores (_) or slashes (/), but [_/a-zA-Z] will.
The regular expressions accepted by regcmp differ slightly from other utilities (that is, sed, grep, awk, ed, and so forth).
regex with the -e option forces subsequent commands to be ignored. In other words, if a backquoted statement appears as follows:
`regex -e ...; command1; command2`
command1 and command2 would never be executed. However, dividing the expression into two:
`regex -e ...``command1; command2`
would yield the desired result.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO awk(1), cut(1), grep(1), paste(1), sed(1), regcmp(3C), attributes(5)SunOS 5.10 12 Jul 1999 regex(1F)