grep
- Regex Cheat Sheet
- Linux Grep Command Cheat Sheet
- Perl Regular Expression Cheat Sheet
- C# Regular Expressions Cheat Sheet
BBEdit-TextWrangler Regular Expression Cheat-Sheet - BBEdit-TextWranglerRegExCheatSheet.txt. BBEdit-TextWrangler Regular Expression Cheat-Sheet - BBEdit-TextWranglerRegExCheatSheet.txt. Skip to content. With or without Grep; use either when you wish to find or replace with a line break. Note that you should avoid considerations of. General Regular Expression Processor Oper ation Option Exam ple Find a string in 1 or more files grep 'string' filename1 filename2. Filena men Case insens itive search i grep -i 'string' filename Use regular expres sions (regex) grep 'regex' filename Look for words w grep -w 'word' filename. Regular expressions can be made case insensitive using (?i). In backreferences, the strings can be converted to lower or upper case using L or U (e.g. This requires PERL = TRUE. CC BY Ian Kopacka. ian.kopacka@ages.at Regular expressions can conveniently be created using rex::rex.
grep is an acronym that stands for 'Global Regular Expressions Print'. grep is a program which scans a specified file or files line by line, returning lines that contain a pattern. A pattern is an expression that specifies a set of strings by interpreting characters as meta-characters. For example the asterisk meta character (*) is interpreted as meaning 'zero or more of the preceding element'. This enables users to type a short series of characters and meta characters into a grep command to have the computer show us what lines in which files match.
GREP Cheat Sheet GREP in InDesign is a powerful way to find patterns of text, then do something to that found text. To create a GREP expression that forms the basis of that search pattern, you’ll need to master many regular expressions (the RE in GREP). Don’t worry if you can’t remember them all, though.
The standard grep command looks like:
grep ' grep prints the search results to the screen (stdout) and returns the following exit values:
Regex Cheat Sheet
0 A match was found.1 No match was found.
1 A syntax error was found or a file was inaccessible(even if matches were found).Some common flags are: -c for counting the number of successful matches and not printing the actual matches, -i to make the search case insensitive, -n to print the line number before each match printout, -v to take the complement of the regular expression (i.e. return the lines which don't match), and -l to print the file names of files with lines which match the expression.
egrep
egrep is an acronym that stands for 'Extended Global Regular Expressions Print'.
The 'E' in egrep means treat the pattern as a regular expression. 'Extended Regular Expressions' abbreviated 'ERE' is enabled in egrep. egrep (which is the same as grep -E) treats +, ?, |, (, and ) as meta-characters.
In basic regular expressions (with grep), the meta-characters ?, +, {, |, (, and ) lose their special meaning. If you want grep to treat these characters as meta-characters, escape them ?, +, {, |, (, and ).
For example, here grep uses basic regular expressions where the plus is treated literally, any line with a plus in it is returned.
grep '+' myfile.txtegrep on the other hand treats the '+' as a meta character and returns every line because plus is interpreted as 'one or more times'.
egrep '+' myfile.txtHere every line is returned because the + was treated by egrep as a meta character. normal grep would have searched only for lines with a literal +.
fgrep
fgrep is an acronym that stands for 'Fixed-string Global Regular Expressions Print'.
fgrep (which is the same as grep -F) is fixed or fast grep and behaves as grep but does NOT recognize any regular expression meta-characters as being special. The search will complete faster because it only processes a simple string rather than a complex pattern.
Linux Grep Command Cheat Sheet
For example, if I wanted to search my .bash_profile for a literal dot (.) then using grep would be difficult because I would have to escape the dot because dot is a meta character that means 'wild-card, any single character':
grep '.' myfile.txtThe above command returns every line of myfile.txt. Do this instead:
fgrep '.' myfile.txtThen only the lines that have a literal '.' in them are returned. fgrep helps us not bother escaping our meta characters.
pgrep
pgrep is an acronym that stands for 'Process-ID Global Regular Expressions Print'.
pgrep looks through the currently running processes and lists the process IDs which matches the selection criteria to stdout. pgrep is handy when all you want to know is the process id integer of a process. For example, if I wanted to know only the process ID of my mysql process I would use the command pgrep mysql which would return a process ID like 7312.
Cheat sheet based off the Udemy cysa+ course from Jason Dion – video 75 as i’m sure i’ll end up looking for it at some point in the future.
REGEX:
[] – Match a single instance of a chracter from a range such as a-z A-Z 0-9 or for all [a-zA-Z0-9]
[s] – Match whitespace
[d] – Match a digit
+ – Match one or more occurrences e.g. d+-
*- Match zero or more occurrences e.g. d*
? – Match one or none occureences e.g. d?
{} – Match the number of times within the braces e.g. d{3} finds 3 digits in a row or d{7-10} matches 7,8,9 or 10 digits in a row
| – OR
^ – Only search at the start of a line
$ – Only search at the end of a line
GREP:
Perl Regular Expression Cheat Sheet
-F = search for a literal value, can use “” instead of -F
-r = recursive
-i = Ignore case sensitivity
-v = Find things which do not match
-w = Treat search strings as words (instead of parts of words)
C# Regular Expressions Cheat Sheet
-c = Show count of matches
-l = Return names of files containing matches
-L = Return names of files without matches