Is it possible to combine a regular expression with a aritmetical expression? For example, taking a 8-numbers caracter sequece and casting each output of a grep, comparing to a constant.
THX! (2 Replies)
What does the regular expression +~).*'] mean while using it with regexec.When the string "RCHNUSNT35C~rs07/ASM-RS07" is used with the regular expression +~).*'] regexec gives an error. I know what regexec does,but i do not understand what this expression means wrt to this string...
any help... (2 Replies)
I currently list and sort all the files in a directory which begin with an Upper Case C and end with the extension '#finished#'.
Here is the command I use:
ls -tr $currentDir/*.#finished#
what i need to do now is list all the files in a directory that begin with upper case C and end... (3 Replies)
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
++... (3 Replies)
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... (1 Reply)
Hello All,
I'm trying to extract the lines between two consecutive elements of an array from a file.
My array looks like:
problem_arr=(PRS111 PRS213 PRS234)
j=0
while } ]
do
k=`expr $j + 1`
sed -n "/${problem_arr}/,/${problem_arr}/p" problemid.txt
---some operation goes... (11 Replies)
Hi,
I am quite knew to scripting and I am trying to get a regular expression to work to check that a user enters a valid version number such as 1 or 1.1 or 12.3 etc. I dont seem to be able to get it to work as it picks up versions such as 1.......2. I only want it to work with a single dot.... (12 Replies)
I would like to extract "JDBC Thin Client" from (PROGRAM=JDBC Thin Client); and "C:\Python26\python.exe" from (PROGRAM=C:\Python26\python.exe); "txm_v_awsrf_db.pr" from (PROGRAM=txm_v_awsrf_db.pr).
if input line like "(PROGRAM=)", it return unknown.
Would you help suggest a regular... (4 Replies)
Discussion started by: cstsang
4 Replies
LEARN ABOUT V7
grep
GREP(1) General Commands Manual GREP(1)NAME
grep, egrep, fgrep - search a file for a pattern
SYNOPSIS
grep [ option ] ... expression [ file ] ...
egrep [ option ] ... [ expression ] [ file ] ...
fgrep [ option ] ... [ strings ] [ file ]
DESCRIPTION
Commands of the grep family search the input files (standard input default) for lines matching a pattern. Normally, each line found is
copied to the standard output; unless the -h flag is used, the file name is shown if there is more than one input file.
Grep patterns are limited regular expressions in the style of ed(1); it uses a compact nondeterministic algorithm. Egrep patterns are full
regular expressions; it uses a fast deterministic algorithm that sometimes needs exponential space. Fgrep patterns are fixed strings; it
is fast and compact.
The following options are recognized.
-v All lines but those matching are printed.
-c Only a count of matching lines is printed.
-l The names of files with matching lines are listed (once) separated by newlines.
-n Each line is preceded by its line number in the file.
-b Each line is preceded by the block number on which it was found. This is sometimes useful in locating disk block numbers by con-
text.
-s No output is produced, only status.
-h Do not print filename headers with output lines.
-y Lower case letters in the pattern will also match upper case letters in the input (grep only).
-e expression
Same as a simple expression argument, but useful when the expression begins with a -.
-f file
The regular expression (egrep) or string list (fgrep) is taken from the file.
-x (Exact) only lines matched in their entirety are printed (fgrep only).
Care should be taken when using the characters $ * [ ^ | ? ' " ( ) and in the expression as they are also meaningful to the Shell. It is
safest to enclose the entire expression argument in single quotes ' '.
Fgrep searches for lines that contain one of the (newline-separated) strings.
Egrep accepts extended regular expressions. In the following description `character' excludes newline:
A followed by a single character matches that character.
The character ^ ($) matches the beginning (end) of a line.
A . matches any character.
A single character not otherwise endowed with special meaning matches that character.
A string enclosed in brackets [] matches any single character from the string. Ranges of ASCII character codes may be abbreviated
as in `a-z0-9'. A ] may occur only as the first character of the string. A literal - must be placed where it can't be mistaken as
a range indicator.
A regular expression followed by * (+, ?) matches a sequence of 0 or more (1 or more, 0 or 1) matches of the regular expression.
Two regular expressions concatenated match a match of the first followed by a match of the second.
Two regular expressions separated by | or newline match either a match for the first or a match for the second.
A regular expression enclosed in parentheses matches a match for the regular expression.
The order of precedence of operators at the same parenthesis level is [] then *+? then concatenation then | and newline.
SEE ALSO ed(1), sed(1), sh(1)DIAGNOSTICS
Exit status is 0 if any matches are found, 1 if none, 2 for syntax errors or inaccessible files.
BUGS
Ideally there should be only one grep, but we don't know a single algorithm that spans a wide enough range of space-time tradeoffs.
Lines are limited to 256 characters; longer lines are truncated.
GREP(1)