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.

2019年5月16日 · Here's an example of grep -q: scanning the output of a command for a particular value, then performing an action if the value is found: if docker context ls | grep -q dm-manager; then docker context rm dm-manager fi If the list of docker contexts contains dm-manager then remove docker context dm-manager.

2010年1月1日 · Recursive grep is, of course, still preferable if available, but there's little reason to avoid the xargs recipe (do use -H for the grep to avoid the final invocation of grep getting passed only a single filename, though).

2010年11月8日 · grep -nr 'yourString*' . The dot at the end searches the current directory. Meaning for each parameter:-n Show relative line number in the file 'yourString*' String for search, followed by a wildcard character -r Recursively search subdirectories listed .

@Chris it's possible you don't have *.scss files in current directory but somewhere deeper in subdirs so grep does not look in all the files you wanted. You should use --include option to tell grep to look recursively for files that matches specific patterns: grep -r x --include '*.scss' .

2017年1月8日 · From "man grep": three variant programs egrep, fgrep and rgrep are available. egrep is the same as grep -E. fgrep is the same as grep -F. rgrep is the same as grep -r. Direct invocation as either egrep or fgrep is deprecated, but is provided to allow historical applications that rely on them to run unmodified.

In GNU grep, there is no difference in available functionality between basic and extended syntaxes. In other implementations, basic regular expressions are less powerful. The following description applies to extended regular expressions; differences for basic regular expressions are summarized afterwards.

2013年6月16日 · The ERE option means the same regular expressions, more or less, as used to be recognized by the egrep command, which is no longer a part of POSIX (having been replaced by grep -E, and fgrep by grep -F).

2011年12月1日 · The grep utility looks for patterns inside files; it's irrelevant if what you care about is the file's name. Shell wildcard patterns are the way to match files by their names. In modern shells, wildcard patterns have the same expressive power as regular expressions (i.e. what you can do with one, you can do with the other), but they have a ...

2008年9月18日 · Another grep tool I now use all the time on Windows is AstroGrep: Its ability to show me more than just the line search (i.e. the --context=NUM of a command-line grep) is invaluable. And it is fast. Very fast, even on an old computer with non-SSD drive (I know, they used to do this hard drive with spinning disks, called platters, crazy right?)