Script Course - Revision history

Bacchas: /* AWK Command */

2019-11-14T17:12:17Z

AWK Command

← Older revision		Revision as of 17:12, 14 November 2019
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	'''Like sed, the awk command searches for patterns of text and performs some action on the text found. However, the awk command treats each line of text as a record in a database, and each word in a line as a database field. For example, the line “Hello, how are you?” has four fields: “Hello,” “how,” “are,” and “you?”. These fields can be referenced in the awk command using $1, $2, $3, and $4. For example, to display only the first and fourth words only on lines of the prologue file that contains the word “the,” you can use the fol- lowing command:		'''Like sed, the awk command searches for patterns of text and performs some action on the text found. However, the awk command treats each line of text as a record in a database, and each word in a line as a database field. For example, the line “Hello, how are you?” has four fields: “Hello,” “how,” “are,” and “you?”. These fields can be referenced in the awk command using $1, $2, $3, and $4. For example, to display only the first and fourth words only on lines of the prologue file that contains the word “the,” you can use the fol- lowing command:
	'''		'''
	cat prologue \| awk ’/the/ {print $1, $4}’		cat prologue \| awk ’/the/ {print $1, $4}’

			find . -type f $ -name ".nef" -o -name ".tif" $ \| awk '/cable/ {print $1}'

	[[File:Bashenvvariables.png\|thumb\|Bash Environment Variables]]		[[File:Bashenvvariables.png\|thumb\|Bash Environment Variables]]
	'''By default, the awk command uses space or tab characters as delimiters for each field in a line. Most configuration files on Linux systems, however, are delimited using colon ( : ) char- acters. To change the delimiter that awk uses, you can specify the –F option to the com- mand. For example, the following example lists the last 10 lines of the colon-delimited file / etc/passwd and views only the 6th and 7th fields for lines that contain the word “bob” in the last 10 lines of the file'''		'''By default, the awk command uses space or tab characters as delimiters for each field in a line. Most configuration files on Linux systems, however, are delimited using colon ( : ) char- acters. To change the delimiter that awk uses, you can specify the –F option to the com- mand. For example, the following example lists the last 10 lines of the colon-delimited file / etc/passwd and views only the 6th and 7th fields for lines that contain the word “bob” in the last 10 lines of the file'''

Bacchas at 14:26, 28 August 2019

2019-08-28T14:26:53Z

← Older revision		Revision as of 14:26, 28 August 2019
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	=[[Bash\| Bash menu]]-[[Main_Page\| Home]]=		=[[Bash\| Bash menu]]-[[Main_Page\| Home]]=
			[[Category:Bash]]

Bacchas: /* AWK Command */

2019-04-25T21:19:50Z

AWK Command

← Older revision		Revision as of 21:19, 25 April 2019
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	# prints lines 1 and 7 with search term 'system' \t adds the tab between fields		# prints lines 1 and 7 with search term 'system' \t adds the tab between fields
	cat /etc/passwd \| awk -F : '/system/ {print $1, "\t"$7'		cat /etc/passwd \| awk -F : '/system/ {print $1, "\t"$7'
			# prints dir contents with links and p tags
			ls \| awk -F: '{print "<p> <a href=\""$1 "\">"$1 "</a></p>"}' > index.html

	~~ls -l \| grep file\w* \| awk -F: ' {print "<p>" $2"</p>"}'~~
	===List Environment Variables===		===List Environment Variables===

Bacchas at 20:39, 25 April 2019

2019-04-25T20:39:20Z

← Older revision		Revision as of 20:39, 25 April 2019
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	'''By default, the awk command uses space or tab characters as delimiters for each field in a line. Most configuration files on Linux systems, however, are delimited using colon ( : ) char- acters. To change the delimiter that awk uses, you can specify the –F option to the com- mand. For example, the following example lists the last 10 lines of the colon-delimited file / etc/passwd and views only the 6th and 7th fields for lines that contain the word “bob” in the last 10 lines of the file'''		'''By default, the awk command uses space or tab characters as delimiters for each field in a line. Most configuration files on Linux systems, however, are delimited using colon ( : ) char- acters. To change the delimiter that awk uses, you can specify the –F option to the com- mand. For example, the following example lists the last 10 lines of the colon-delimited file / etc/passwd and views only the 6th and 7th fields for lines that contain the word “bob” in the last 10 lines of the file'''
	tail /etc/passwd \| awk –F : ’/bob/ {print $6, $7}’		tail /etc/passwd \| awk –F : ’/bob/ {print $6, $7}’
			# prints lines 1 and 7 with search term 'system' \t adds the tab between fields
			cat /etc/passwd \| awk -F : '/system/ {print $1, "\t"$7'

			ls -l \| grep file\w* \| awk -F: ' {print "<p>" $2"</p>"}'
	===List Environment Variables===		===List Environment Variables===

Bacchas: /* Select Case */

2019-04-08T20:22:36Z

Select Case

@@ Line 126: / Line 126: @@
 </pre>
 ==Select Case==
 =[[Bash| Bash menu]]-[[Main_Page| Home]]=

Bacchas at 19:53, 8 April 2019

2019-04-08T19:53:42Z

@@ Line 93: / Line 93: @@
 '''Many environment variables are set by default in the BASH shell. To see a list of these vari- ables and their current values, you can use the set command, '''
   set | less
-=[[Bash| Bash menu]]-[[Main_Page| Home]]=
 ===Setting User Variables===
 *They can contain alphanumeric characters (0–9, A–Z, a–z), the dash (-) character, or the underscore (_) character.
@@ Line 113: / Line 113: @@
 *~/.bash_login
 *~/.profile

Bacchas at 18:26, 7 April 2019

2019-04-07T18:26:57Z

← Older revision		Revision as of 18:26, 7 April 2019
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	set \| less		set \| less
	=[[Bash\| Bash menu]]-[[Main_Page\| Home]]=		=[[Bash\| Bash menu]]-[[Main_Page\| Home]]=
			===Setting User Variables===
			*They can contain alphanumeric characters (0–9, A–Z, a–z), the dash (-) character, or the underscore (_) character.
			*They must not start with a number.
			*They are typically capitalized to follow convention (e.g., HOME, PATH
			MYVAR = "hello"
			echo $MYVAR
			Use the '''export''' command to make a variable available to all sub-shells
			export MYVAR
			#env command is used to view user variables
			env \|grep MYVAR

			===Environment Files===
			Recall that variables are stored in memory. When a user exits the BASH shell, all variables stored in memory are destroyed along with the shell itself. To ensure that variables are acces- sible to a shell at all times, you must place variables in a file that is executed each time a user logs in and starts a BASH shell. These files are called environment files. Common BASH shell environment files and the order in which they are typically executed are as follows:
			*/etc/profile
			*/etc/bashrc
			*~/.bashrc
			*~/.bash_profile
			*~/.bash_login
			*~/.profile

Bacchas at 17:43, 7 April 2019

2019-04-07T17:43:10Z

← Older revision		Revision as of 17:43, 7 April 2019
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	the word “the,” you can use the following command:'''		the word “the,” you can use the following command:'''
	cat prologue \| sed /the/d		cat prologue \| sed /the/d
	~~[[File:Bashenvvariables.png\|thumb\|Bash Environment Variables]]~~
	===AWK Command===		===AWK Command===
	'''Like sed, the awk command searches for patterns of text and performs some action on the text found. However, the awk command treats each line of text as a record in a database, and each word in a line as a database field. For example, the line “Hello, how are you?” has four fields: “Hello,” “how,” “are,” and “you?”. These fields can be referenced in the awk command using $1, $2, $3, and $4. For example, to display only the first and fourth words only on lines of the prologue file that contains the word “the,” you can use the fol- lowing command:		'''Like sed, the awk command searches for patterns of text and performs some action on the text found. However, the awk command treats each line of text as a record in a database, and each word in a line as a database field. For example, the line “Hello, how are you?” has four fields: “Hello,” “how,” “are,” and “you?”. These fields can be referenced in the awk command using $1, $2, $3, and $4. For example, to display only the first and fourth words only on lines of the prologue file that contains the word “the,” you can use the fol- lowing command:
	'''		'''
	cat prologue \| awk ’/the/ {print $1, $4}’		cat prologue \| awk ’/the/ {print $1, $4}’
			[[File:Bashenvvariables.png\|thumb\|Bash Environment Variables]]
	'''By default, the awk command uses space or tab characters as delimiters for each field in a line. Most configuration files on Linux systems, however, are delimited using colon ( : ) char- acters. To change the delimiter that awk uses, you can specify the –F option to the com- mand. For example, the following example lists the last 10 lines of the colon-delimited file / etc/passwd and views only the 6th and 7th fields for lines that contain the word “bob” in the last 10 lines of the file'''		'''By default, the awk command uses space or tab characters as delimiters for each field in a line. Most configuration files on Linux systems, however, are delimited using colon ( : ) char- acters. To change the delimiter that awk uses, you can specify the –F option to the com- mand. For example, the following example lists the last 10 lines of the colon-delimited file / etc/passwd and views only the 6th and 7th fields for lines that contain the word “bob” in the last 10 lines of the file'''
	tail /etc/passwd \| awk –F : ’/bob/ {print $6, $7}’		tail /etc/passwd \| awk –F : ’/bob/ {print $6, $7}’

Bacchas at 17:42, 7 April 2019

2019-04-07T17:42:33Z

← Older revision		Revision as of 17:42, 7 April 2019
Line 81:		Line 81:
	the word “the,” you can use the following command:'''		the word “the,” you can use the following command:'''
	cat prologue \| sed /the/d		cat prologue \| sed /the/d
			[[File:Bashenvvariables.png\|thumb\|Bash Environment Variables]]
	===AWK Command===		===AWK Command===
	'''Like sed, the awk command searches for patterns of text and performs some action on the text found. However, the awk command treats each line of text as a record in a database, and each word in a line as a database field. For example, the line “Hello, how are you?” has four fields: “Hello,” “how,” “are,” and “you?”. These fields can be referenced in the awk command using $1, $2, $3, and $4. For example, to display only the first and fourth words only on lines of the prologue file that contains the word “the,” you can use the fol- lowing command:		'''Like sed, the awk command searches for patterns of text and performs some action on the text found. However, the awk command treats each line of text as a record in a database, and each word in a line as a database field. For example, the line “Hello, how are you?” has four fields: “Hello,” “how,” “are,” and “you?”. These fields can be referenced in the awk command using $1, $2, $3, and $4. For example, to display only the first and fourth words only on lines of the prologue file that contains the word “the,” you can use the fol- lowing command:
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	tail /etc/passwd \| awk –F : ’/bob/ {print $6, $7}’		tail /etc/passwd \| awk –F : ’/bob/ {print $6, $7}’
	===List Environment Variables===		===List Environment Variables===
	~~[[File:Bashenvvariables.png\|thumb\|Bash Environment Variables]]~~
	'''Many environment variables are set by default in the BASH shell. To see a list of these vari- ables and their current values, you can use the set command, '''		'''Many environment variables are set by default in the BASH shell. To see a list of these vari- ables and their current values, you can use the set command, '''
	set \| less		set \| less
	=[[Bash\| Bash menu]]-[[Main_Page\| Home]]=		=[[Bash\| Bash menu]]-[[Main_Page\| Home]]=

Bacchas at 17:42, 7 April 2019

2019-04-07T17:42:05Z

← Older revision		Revision as of 17:42, 7 April 2019
Line 81:		Line 81:
	the word “the,” you can use the following command:'''		the word “the,” you can use the following command:'''
	cat prologue \| sed /the/d		cat prologue \| sed /the/d
	~~[[File:Bashenvvariables.png\|thumb\|Bash Environment Variables]]~~
	===AWK Command===		===AWK Command===
	'''Like sed, the awk command searches for patterns of text and performs some action on the text found. However, the awk command treats each line of text as a record in a database, and each word in a line as a database field. For example, the line “Hello, how are you?” has four fields: “Hello,” “how,” “are,” and “you?”. These fields can be referenced in the awk command using $1, $2, $3, and $4. For example, to display only the first and fourth words only on lines of the prologue file that contains the word “the,” you can use the fol- lowing command:		'''Like sed, the awk command searches for patterns of text and performs some action on the text found. However, the awk command treats each line of text as a record in a database, and each word in a line as a database field. For example, the line “Hello, how are you?” has four fields: “Hello,” “how,” “are,” and “you?”. These fields can be referenced in the awk command using $1, $2, $3, and $4. For example, to display only the first and fourth words only on lines of the prologue file that contains the word “the,” you can use the fol- lowing command:
Line 89:		Line 89:
	tail /etc/passwd \| awk –F : ’/bob/ {print $6, $7}’		tail /etc/passwd \| awk –F : ’/bob/ {print $6, $7}’
	===List Environment Variables===		===List Environment Variables===
			[[File:Bashenvvariables.png\|thumb\|Bash Environment Variables]]
	'''Many environment variables are set by default in the BASH shell. To see a list of these vari- ables and their current values, you can use the set command, '''		'''Many environment variables are set by default in the BASH shell. To see a list of these vari- ables and their current values, you can use the set command, '''
	set \| less		set \| less
	=[[Bash\| Bash menu]]-[[Main_Page\| Home]]=		=[[Bash\| Bash menu]]-[[Main_Page\| Home]]=