What expressions would match the pattern (^[0-9]..[a-zA-Z ]+$) in …
2021年11月3日 · Let's break it down. First of all, note that this RegExp uses the "Extended regular expression" syntax (ERE) - the + is a metacharacter that doesn't work in the "Basic regular expression" syntax that grep uses by default (meaning it would match itself and require a literal + at that position), so if you want to use that RegEx with grep, you will need to pass the -E option.
Grep: how to add an "OR" condition? - Unix & Linux Stack Exchange
2011年12月1日 · First we start by defining what we know about our pattern: We know that we are looking for the end of the name. Ergo we use the "$" operand to define that each line has to end with the defined pattern. We know that the pattern needs to be either JPEG or JPG. To this we use the pipeline "|" as an or operand. Our pattern is now: ((JPEG)|(JPG))$
What is the difference between grep -e and grep -E option?
I am trying to understand the difference between grep -e and grep -E. Now from grep manpage I got:-E, --extended-regexp. Interpret PATTERN as an extended regular expression (see below).-e PATTERN, --regexp=PATTERN. Use PATTERN as the pattern; useful to protect patterns beginning with - The above explanation does not make sense for me.
How to run grep with multiple AND patterns?
2016年3月25日 · For potentially gzip-compressed files, you can use zgrep which is generally a shell script wrapper around grep, and use one of the grep solutions above (not the ast-open one as that grep implementation cannot be use by zgrep) or you could use the PerlIO::gzip module of perl which can transparently uncompress files upon input:
shell - How do I grep for multiple patterns with pattern having a …
GNU grep isn't faster with -F, for example (it also has a bug that makes grep -F slower in multibyte locales — the same constant pattern with grep is actually significantly faster!). On the other hand BusyBox grep does benefit a lot from -F on large files.
Reading grep patterns from a file - Unix & Linux Stack Exchange
The argument -E or -F or -P, if any, tells grep which syntax the patterns are written in. With no argument, grep expects basic regular expressions; with -E, grep expects extended regular expressions; with -P (if supported), grep expects Perl regular expressions; and with -F, grep expects literal strings. Whether the patterns come from the ...
special characters - Match with grep when pattern contains …
2017年8月29日 · Another alternative that you shouldn't use that nobody listed : it's possible to escape the dash inside a quoted string so it is understood by grep as a literal character rather than the start of an option, i.e. echo test-test | grep "\-test" will match rather than complain about an unknown -t flag.
grep - Filtered List of Files Containing String - Unix & Linux Stack ...
2017年4月25日 · This will search under /path for file names matching 1 shell pattern *path_string* and run grep only on those files, printing their names if successful. 1: the pattern match is applied to the whole file name starting from /path/
Match exact string using grep - Unix & Linux Stack Exchange
2015年6月2日 · $ grep -inx -d skip 'favicon.ico' * test.txt:1:favicon.ico Grep Manual -x, --line-regexp Select only those matches that exactly match the whole line. For a regular expression pattern, this is like parenthesizing the pattern and then surrounding it with ^ and $.
How to grep lines between start and end pattern? [duplicate]
2015年10月17日 · Here is grep command: grep -o "aaa.*cdn" <(paste -sd_ file) | tr '_' '\n' You can achieve multiline match in grep, but you need to use perl-regexp for grep (-P - which is not supported on every platform, like OS X), so as workaround we're replacing new lines with _ character and after grep, we're changing them back.