Difference between revisions of "Linux"

Revision as of 22:27, 14 November 2016

Favorite Commands:

Some Notation:
FILE: a filename
DIRECTORY:
PATH: a directory/file location
LINE: a line's contents
COMMAND: a command like awk, cat, echo, grep, etc. 
LITERAL: a literal/static variable no REGEX
REGEX: "REGular EXpression"...a pattern matching expression
DATE: a date...format my vary
TIME: a time...format my vary
NUMBER: a numeric value
SEPARATOR: a field separator
VARIABLE: a variable
/dev/null: a device file representing nothing

find . -type f -exec grep -n "LITERAL/REGEX" {} /dev/null \; # search regular files for "LITERAL/REGEX" inside...printing "path/filename:line:content"
find . -type f -exec ls -hlatr {} \; | sort -hk5,5 # long list all files under a directory, sort smallest to largest (human size)
rm -rf PATH # remove a "PATH" and all content
awk -F'SEPARATOR' '{print $NUMBER}' # print the column "NUMBER" delimited by "SEPARATOR"
locate LITERAL # print the PATH of file name matching "LITERAL"
less -S FILE # page "FILE" with no line wrap
du -hd1 | sort -h # disk usage (human size),one level deep and sum by directory...pipe to sort smallest to largest
wget PATH # get "PATH" from http/ftp
scp PATH1 username@hostname:PATH2 # put "PATH1" to "PATH2"
scp -r PATH1 username@hostname:PATH2 # same as above, but recursively gets directory and all files under it
scp username@hostname:PATH1 PATH2 # get "PATH1" to "PATH2"
scp username@hostname:PATH1 PATH2 # same as above, but recursively gets directory and all files under it
cat FILE # display contents of "FILE"
vi FILE # edit/view "FILE"
echo $VARIABLE # display contents of variable "VARIABLE"
>FILE # zeros out "FILE"
cp /dev/null FILE # zeros out "FILE"
\COMMAND # unalias "COMMAND"
"COMMAND" # unalias "COMMAND"
while [ 1 ]; do COMMANDS; sleep NUMBER; done # repeat COMMAND with NUMBER seconds between
cat FILE | while read LINE; do COMMAND; done # read a file line by line doing a COMMAND until file's end

@@ Line 2: / Line 2: @@
 <pre>
-Some variables:
+Some Notation:
 FILE: a filename
-PATH: a directory/file path
+DIRECTORY:
+PATH: a directory/file location
 LINE: a line's contents
-COMMANDS: a/many commands like awk, cat, echo, grep, etc.
+COMMAND: a command like awk, cat, echo, grep, etc.
 LITERAL: a literal/static variable no REGEX
 REGEX: "REGular EXpression"...a pattern matching expression
@@ Line 12: / Line 13: @@
 TIME: a time...format my vary
 NUMBER: a numeric value
+SEPARATOR: a field separator
+VARIABLE: a variable
+/dev/null: a device file representing nothing
 </pre>
-* find . -type f -exec grep -n "foo" {} /dev/null \;  # search regular files for "foo" inside...printing "path/filename:line:content"
+* find . -type f -exec grep -n "LITERAL/REGEX" {} /dev/null \;  # search regular files for "LITERAL/REGEX" inside...printing "path/filename:line:content"
 * find . -type f -exec ls -hlatr {} \; | sort -hk5,5  # long list all files under a directory, sort smallest to largest (human size)
-* rm -rf foo  # remove a directory "foo" and all content
+* rm -rf PATH  # remove a "PATH" and all content
-* awk -F'foo' '{print $number}'  # print the column (number) delimited by "foo"
+* awk -F'SEPARATOR' '{print $NUMBER}'  # print the column "NUMBER" delimited by "SEPARATOR"
-* locate foo  # print the path/filename of file name matching "foo"
+* locate LITERAL  # print the PATH of file name matching "LITERAL"
-* less -S foo # pager with no line wrap
+* less -S FILE # page "FILE" with no line wrap
 * du -hd1 | sort -h # disk usage (human size),one level deep and sum by directory...pipe to sort smallest to largest
-* wget foo  # get a file from http/ftp
+* wget PATH  # get "PATH" from http/ftp
-* scp foo username@hostname:/tmp  # put "foo" to location
+* scp PATH1 username@hostname:PATH2  # put "PATH1" to "PATH2"
-* scp username@hostname:/tmp/foo .  # get "foo" from location
+* scp -r PATH1 username@hostname:PATH2  # same as above, but recursively gets directory and all files under it
-* cat foo  # display contents of file "foo"
+* scp username@hostname:PATH1 PATH2  # get "PATH1" to "PATH2"
-* vi foo  # edit/view file "foo"
+* scp username@hostname:PATH1 PATH2  # same as above, but recursively gets directory and all files under it
-* echo $foo  # display contents of variable "foo"
+* cat FILE  # display contents of "FILE"
-* >foo || cp /dev/null foo  # zeros out file "foo"
+* vi FILE  # edit/view "FILE"
-* \foo || "foo"  # unalias command "foo"
+* echo $VARIABLE  # display contents of variable "VARIABLE"
-* while [ 1 ]; do foo; sleep foo; done
+* >FILE  # zeros out "FILE"
+* cp /dev/null FILE  # zeros out "FILE"
+* \COMMAND  # unalias "COMMAND"
+* "COMMAND"  # unalias "COMMAND"
+* while [ 1 ]; do COMMANDS; sleep NUMBER; done  # repeat COMMAND with NUMBER seconds between
+* cat FILE | while read LINE; do COMMAND; done  # read a file line by line doing a COMMAND until file's end

Difference between revisions of "Linux"

From kemiko

Revision as of 22:27, 14 November 2016