From 19f6739cbaa06b6b40b835115a0361f5e77bd0e0 Mon Sep 17 00:00:00 2001
From: Sriram Sundarraj <sriram.s.1994@gmail.com>
Date: Fri, 24 Apr 2015 02:36:54 +0530
Subject: [bash/en] Fixed overflowing line.

---
 bash.html.markdown | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 3b163638..35bed9a2 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -235,11 +235,13 @@ uniq -d file.txt
 cut -d ',' -f 1 file.txt
 # replaces every occurrence of 'okay' with 'great' in file.txt, (regex compatible)
 sed -i 's/okay/great/g' file.txt
-# print to stdout all lines of file.txt which match some regex, the example prints lines which begin with "foo" and end in "bar"
+# print to stdout all lines of file.txt which match some regex
+# The example prints lines which begin with "foo" and end in "bar"
 grep "^foo.*bar$" file.txt
 # pass the option "-c" to instead print the number of lines matching the regex
 grep -c "^foo.*bar$" file.txt
-# if you literally want to search for the string, and not the regex, use fgrep (or grep -F)
+# if you literally want to search for the string,
+# and not the regex, use fgrep (or grep -F)
 fgrep "^foo.*bar$" file.txt 
 
 
-- 
cgit v1.2.3


From 9d3462953604d0d331191bb1fca82295e1ece6ed Mon Sep 17 00:00:00 2001
From: Etan Reisner <deryni@unreliablesource.net>
Date: Sun, 26 Apr 2015 13:22:48 -0400
Subject: Add myself as a contributor.

---
 bash.html.markdown | 1 +
 1 file changed, 1 insertion(+)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 35bed9a2..b9cd53ff 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -10,6 +10,7 @@ contributors:
     - ["Anton Strömkvist", "http://lutic.org/"]
     - ["Rahil Momin", "https://github.com/iamrahil"]
     - ["Gregrory Kielian", "https://github.com/gskielian"]
+    - ["Etan Reisner", "https://github.com/deryni"]
 filename: LearnBash.sh
 ---
 
-- 
cgit v1.2.3


From e2ca2c9550474ca3dad0f7ef8735e614da081258 Mon Sep 17 00:00:00 2001
From: Etan Reisner <deryni@unreliablesource.net>
Date: Sun, 26 Apr 2015 13:32:41 -0400
Subject: Add another very common shell variable assignment mistake.

---
 bash.html.markdown | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index b9cd53ff..77ee37f6 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -37,7 +37,14 @@ VARIABLE="Some string"
 # But not like this:
 VARIABLE = "Some string"
 # Bash will decide that VARIABLE is a command it must execute and give an error
-# because it couldn't be found.
+# because it can't be found.
+
+# Or like this:
+Variable= 'Some string'
+# Bash will decide that 'Some string' is a command it must execute and give an
+# error because it can't be found. (In this case the 'Variable=' part is seen
+# as a variable assignment valid only for the scope of the 'Some string'
+# command.)
 
 # Using the variable:
 echo $VARIABLE
-- 
cgit v1.2.3


From aa11cc659de990a6c4d4104bcc733f373b079ae7 Mon Sep 17 00:00:00 2001
From: Etan Reisner <deryni@unreliablesource.net>
Date: Mon, 27 Apr 2015 07:30:17 -0400
Subject: Follow variable capitalization on this branch.

---
 bash.html.markdown | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 77ee37f6..e0c12f97 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -40,9 +40,9 @@ VARIABLE = "Some string"
 # because it can't be found.
 
 # Or like this:
-Variable= 'Some string'
+VARIABLE= 'Some string'
 # Bash will decide that 'Some string' is a command it must execute and give an
-# error because it can't be found. (In this case the 'Variable=' part is seen
+# error because it can't be found. (In this case the 'VARIABLE=' part is seen
 # as a variable assignment valid only for the scope of the 'Some string'
 # command.)
 
-- 
cgit v1.2.3


From 8758bb845b063b76b55d2c178d0dc393b2a39c5c Mon Sep 17 00:00:00 2001
From: Andrey Samsonov <andrey.samsonov@gmail.com>
Date: Sat, 2 May 2015 15:34:56 +0400
Subject: Clear that length and position can be set by variable in substring
 extraction

---
 bash.html.markdown | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index e0c12f97..81f85d28 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -59,7 +59,8 @@ echo ${VARIABLE/Some/A}
 # This will substitute the first occurance of "Some" with "A"
 
 # Substring from a variable
-echo ${VARIABLE:0:7}
+LENGTH=7
+echo ${VARIABLE:0:LENGTH}
 # This will return only the first 7 characters of the value
 
 # Default value for variable
-- 
cgit v1.2.3


From 6848f45ebeee759afdaa34e6cdf367fe31bf1bab Mon Sep 17 00:00:00 2001
From: Andrey Samsonov <andrey.samsonov@gmail.com>
Date: Sat, 2 May 2015 16:21:03 +0400
Subject: Clear explanation of default value expression

---
 bash.html.markdown | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index e0c12f97..58dc3003 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -64,7 +64,8 @@ echo ${VARIABLE:0:7}
 
 # Default value for variable
 echo ${FOO:-"DefaultValueIfFOOIsMissingOrEmpty"}
-# This works for null (FOO=), empty string (FOO=""), zero (FOO=0) returns 0
+# This works for null (FOO=) and empty string (FOO=""); zero (FOO=0) returns 0.
+# Note that it only returns default value and doesn't change variable value.
 
 # Builtin variables:
 # There are some useful builtin variables, like
-- 
cgit v1.2.3


From 8b7a2fff9a71b8fa8754947434b8b1f184ed2de1 Mon Sep 17 00:00:00 2001
From: Etan Reisner <deryni@unreliablesource.net>
Date: Wed, 29 Apr 2015 22:11:20 -0400
Subject: Don't use ALL_CAPS variable names.

ALL_CAPS variable names are traditionally "reserved" for use by the
shell/system.

(People often try to use PATH for things locally and then wonder why their
commands all stop working for example.
---
 bash.html.markdown | 58 +++++++++++++++++++++++++++---------------------------
 1 file changed, 29 insertions(+), 29 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 4c50c653..937d2c96 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -32,40 +32,40 @@ echo Hello world!
 echo 'This is the first line'; echo 'This is the second line'
 
 # Declaring a variable looks like this:
-VARIABLE="Some string"
+Variable="Some string"
 
 # But not like this:
-VARIABLE = "Some string"
-# Bash will decide that VARIABLE is a command it must execute and give an error
+Variable = "Some string"
+# Bash will decide that Variable is a command it must execute and give an error
 # because it can't be found.
 
 # Or like this:
-VARIABLE= 'Some string'
+Variable= 'Some string'
 # Bash will decide that 'Some string' is a command it must execute and give an
-# error because it can't be found. (In this case the 'VARIABLE=' part is seen
+# error because it can't be found. (In this case the 'Variable=' part is seen
 # as a variable assignment valid only for the scope of the 'Some string'
 # command.)
 
 # Using the variable:
-echo $VARIABLE
-echo "$VARIABLE"
-echo '$VARIABLE'
+echo $Variable
+echo "$Variable"
+echo '$Variable'
 # When you use the variable itself — assign it, export it, or else — you write
 # its name without $. If you want to use variable's value, you should use $.
 # Note that ' (single quote) won't expand the variables!
 
 # String substitution in variables
-echo ${VARIABLE/Some/A}
+echo ${Variable/Some/A}
 # This will substitute the first occurance of "Some" with "A"
 
 # Substring from a variable
-LENGTH=7
-echo ${VARIABLE:0:LENGTH}
+Length=7
+echo ${Variable:0:Length}
 # This will return only the first 7 characters of the value
 
 # Default value for variable
-echo ${FOO:-"DefaultValueIfFOOIsMissingOrEmpty"}
-# This works for null (FOO=) and empty string (FOO=""); zero (FOO=0) returns 0.
+echo ${Foo:-"DefaultValueIfFooIsMissingOrEmpty"}
+# This works for null (Foo=) and empty string (Foo=""); zero (Foo=0) returns 0.
 # Note that it only returns default value and doesn't change variable value.
 
 # Builtin variables:
@@ -78,12 +78,12 @@ echo "Scripts arguments seperated in different variables: $1 $2..."
 
 # Reading a value from input:
 echo "What's your name?"
-read NAME # Note that we didn't need to declare a new variable
-echo Hello, $NAME!
+read Name # Note that we didn't need to declare a new variable
+echo Hello, $Name!
 
 # We have the usual if structure:
 # use 'man test' for more info about conditionals
-if [ $NAME -ne $USER ]
+if [ $Name -ne $USER ]
 then
     echo "Your name isn't your username"
 else
@@ -95,14 +95,14 @@ echo "Always executed" || echo "Only executed if first command fails"
 echo "Always executed" && echo "Only executed if first command does NOT fail"
 
 # To use && and || with if statements, you need multiple pairs of square brackets:
-if [ $NAME == "Steve" ] && [ $AGE -eq 15 ]
+if [ $Name == "Steve" ] && [ $Age -eq 15 ]
 then
-    echo "This will run if $NAME is Steve AND $AGE is 15."
+    echo "This will run if $Name is Steve AND $Age is 15."
 fi
 
-if [ $NAME == "Daniya" ] || [ $NAME == "Zach" ]
+if [ $Name == "Daniya" ] || [ $Name == "Zach" ]
 then
-    echo "This will run if $NAME is Daniya OR Zach."
+    echo "This will run if $Name is Daniya OR Zach."
 fi
 
 # Expressions are denoted with the following format:
@@ -171,7 +171,7 @@ echo "There are $(ls | wc -l) items here."
 echo "There are `ls | wc -l` items here."
 
 # Bash uses a case statement that works similarly to switch in Java and C++:
-case "$VARIABLE" in 
+case "$Variable" in
     #List patterns for the conditions you want to meet
     0) echo "There is a zero.";;
     1) echo "There is a one.";;
@@ -179,10 +179,10 @@ case "$VARIABLE" in
 esac
 
 # for loops iterate for as many arguments given:
-# The contents of $VARIABLE is printed three times.
-for VARIABLE in {1..3}
+# The contents of $Variable is printed three times.
+for Variable in {1..3}
 do
-    echo "$VARIABLE"
+    echo "$Variable"
 done
 
 # Or write it the "traditional for loop" way:
@@ -193,16 +193,16 @@ done
 
 # They can also be used to act on files..
 # This will run the command 'cat' on file1 and file2
-for VARIABLE in file1 file2
+for Variable in file1 file2
 do
-    cat "$VARIABLE"
+    cat "$Variable"
 done
 
 # ..or the output from a command
 # This will cat the output from ls.
-for OUTPUT in $(ls)
+for Output in $(ls)
 do
-    cat "$OUTPUT"
+    cat "$Output"
 done
 
 # while loop:
@@ -230,7 +230,7 @@ bar ()
 }
 
 # Calling your function
-foo "My name is" $NAME
+foo "My name is" $Name
 
 # There are a lot of useful commands you should learn:
 # prints last 10 lines of file.txt
-- 
cgit v1.2.3


From e4c261567533921f35ce4e65ebfe6621a128992b Mon Sep 17 00:00:00 2001
From: Levi Bostian <levi.bostian@gmail.com>
Date: Mon, 11 May 2015 21:20:02 -0500
Subject: Fix issue with referring to "output.txt" but examples use
 "output.out"

Fixes https://github.com/adambard/learnxinyminutes-docs/issues/1095
---
 bash.html.markdown | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 937d2c96..ee783c14 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -144,7 +144,7 @@ python hello.py > /dev/null 2>&1
 # if you want to append instead, use ">>":
 python hello.py >> "output.out" 2>> "error.err"
 
-# Overwrite output.txt, append to error.err, and count lines:
+# Overwrite output.out, append to error.err, and count lines:
 info bash 'Basic Shell Features' 'Redirections' > output.out 2>> error.err
 wc -l output.out error.err
 
@@ -152,7 +152,7 @@ wc -l output.out error.err
 # see: man fd
 echo <(echo "#helloworld")
 
-# Overwrite output.txt with "#helloworld":
+# Overwrite output.out with "#helloworld":
 cat > output.out <(echo "#helloworld")
 echo "#helloworld" > output.out
 echo "#helloworld" | cat > output.out
-- 
cgit v1.2.3


From 8909457ae46dc8fb151ef146acb3f6b8402f3407 Mon Sep 17 00:00:00 2001
From: Liam Edwards-Playne <liamzebedee@yahoo.com.au>
Date: Wed, 20 May 2015 11:23:55 +1000
Subject: fix spelling errors

---
 bash.html.markdown | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index ee783c14..c2312d7d 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -56,7 +56,7 @@ echo '$Variable'
 
 # String substitution in variables
 echo ${Variable/Some/A}
-# This will substitute the first occurance of "Some" with "A"
+# This will substitute the first occurence of "Some" with "A"
 
 # Substring from a variable
 Length=7
@@ -74,7 +74,7 @@ echo "Last program return value: $?"
 echo "Script's PID: $$"
 echo "Number of arguments: $#"
 echo "Scripts arguments: $@"
-echo "Scripts arguments seperated in different variables: $1 $2..."
+echo "Scripts arguments separated in different variables: $1 $2..."
 
 # Reading a value from input:
 echo "What's your name?"
-- 
cgit v1.2.3


From de676b62b83fcaaa9977cca9adb9c38383b64f35 Mon Sep 17 00:00:00 2001
From: Liam Edwards-Playne <liamzebedee@yahoo.com.au>
Date: Tue, 26 May 2015 11:25:07 +1000
Subject: fixed spelling error

---
 bash.html.markdown | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index c2312d7d..08182c2c 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -56,7 +56,7 @@ echo '$Variable'
 
 # String substitution in variables
 echo ${Variable/Some/A}
-# This will substitute the first occurence of "Some" with "A"
+# This will substitute the first occurrence of "Some" with "A"
 
 # Substring from a variable
 Length=7
-- 
cgit v1.2.3


From acc9a73c018a28a9c8ead7b108dd1fdfee7a797b Mon Sep 17 00:00:00 2001
From: ksami <ksami.ihide@gmail.com>
Date: Fri, 2 Oct 2015 22:08:27 +0800
Subject: [bash/en] Improved descriptions

---
 bash.html.markdown | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 08182c2c..d4f3d424 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -51,7 +51,7 @@ echo $Variable
 echo "$Variable"
 echo '$Variable'
 # When you use the variable itself — assign it, export it, or else — you write
-# its name without $. If you want to use variable's value, you should use $.
+# its name without $. If you want to use the variable's value, you should use $.
 # Note that ' (single quote) won't expand the variables!
 
 # String substitution in variables
@@ -70,11 +70,11 @@ echo ${Foo:-"DefaultValueIfFooIsMissingOrEmpty"}
 
 # Builtin variables:
 # There are some useful builtin variables, like
-echo "Last program return value: $?"
+echo "Last program's return value: $?"
 echo "Script's PID: $$"
-echo "Number of arguments: $#"
-echo "Scripts arguments: $@"
-echo "Scripts arguments separated in different variables: $1 $2..."
+echo "Number of arguments passed to script: $#"
+echo "All arguments passed to script: $@"
+echo "Script's arguments separated into different variables: $1 $2..."
 
 # Reading a value from input:
 echo "What's your name?"
@@ -108,8 +108,8 @@ fi
 # Expressions are denoted with the following format:
 echo $(( 10 + 5 ))
 
-# Unlike other programming languages, bash is a shell — so it works in a context
-# of current directory. You can list files and directories in the current
+# Unlike other programming languages, bash is a shell so it works in the context
+# of a current directory. You can list files and directories in the current
 # directory with the ls command:
 ls
 
-- 
cgit v1.2.3


From 960ee4a1856db8eadb96277bb2422edfa8f2a81c Mon Sep 17 00:00:00 2001
From: Gabriel Halley <gabhalley@gmail.com>
Date: Wed, 7 Oct 2015 23:11:24 -0400
Subject: removing whitespace all over

---
 bash.html.markdown | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index d4f3d424..191f916a 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -252,7 +252,7 @@ grep "^foo.*bar$" file.txt
 grep -c "^foo.*bar$" file.txt
 # if you literally want to search for the string,
 # and not the regex, use fgrep (or grep -F)
-fgrep "^foo.*bar$" file.txt 
+fgrep "^foo.*bar$" file.txt
 
 
 # Read Bash shell builtins documentation with the bash 'help' builtin:
-- 
cgit v1.2.3


From f4022052471d6dc0a9c2fb8794e1352253b4c5ad Mon Sep 17 00:00:00 2001
From: Awal Garg <awalGarg@users.noreply.github.com>
Date: Wed, 14 Oct 2015 21:10:28 +0530
Subject: [bash/en] use $var with quotes in conditions

---
 bash.html.markdown | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 191f916a..211d2944 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -90,17 +90,26 @@ else
     echo "Your name is your username"
 fi
 
+# NOTE: if $Name is empty, bash sees the above condition as:
+if [ -ne $USER ]
+# which is invalid syntax
+# so the "safe" way to use potentially empty variables in bash is:
+if [ "$Name" -ne $USER ] ...
+# which, when $Name is empty, is seen by bash as:
+if [ "" -ne $USER ] ...
+# which works as expected
+
 # There is also conditional execution
 echo "Always executed" || echo "Only executed if first command fails"
 echo "Always executed" && echo "Only executed if first command does NOT fail"
 
 # To use && and || with if statements, you need multiple pairs of square brackets:
-if [ $Name == "Steve" ] && [ $Age -eq 15 ]
+if [ "$Name" == "Steve" ] && [ "$Age" -eq 15 ]
 then
     echo "This will run if $Name is Steve AND $Age is 15."
 fi
 
-if [ $Name == "Daniya" ] || [ $Name == "Zach" ]
+if [ "$Name" == "Daniya" ] || [ "$Name" == "Zach" ]
 then
     echo "This will run if $Name is Daniya OR Zach."
 fi
-- 
cgit v1.2.3


From 5c8942f7bcb02a59d1e0acefb0069e80de57e01e Mon Sep 17 00:00:00 2001
From: viv1 <f2012058@pilani.bits-pilani.ac.in>
Date: Mon, 19 Oct 2015 02:50:55 +0530
Subject: [bash/en]...Added info on changing directories

---
 bash.html.markdown | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 211d2944..dfbf9a89 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -130,6 +130,15 @@ ls -l # Lists every file and directory on a separate line
 # .txt files in the current directory:
 ls -l | grep "\.txt"
 
+# Since bash works in the context of a current directory, you might want to 
+# run your command in some other directory. We have cd for changing location:
+cd ~    # change to home directory
+cd ..   # go up one directory
+        # (^^say, from /home/username/Downloads to /home/username)
+cd /home/username/Documents   # change to specified directory
+cd ~/Documents/..    # still in home directory..isn't it??
+
+
 # You can redirect command input and output (stdin, stdout, and stderr).
 # Read from stdin until ^EOF$ and overwrite hello.py with the lines
 # between "EOF":
-- 
cgit v1.2.3


From f94dea8379b5e7a28990eac371f9c9cca19ab472 Mon Sep 17 00:00:00 2001
From: Matteo Baglini <matteo.baglini@gmail.com>
Date: Tue, 12 Jan 2016 00:32:03 +0100
Subject: Use proper string comparison syntax

---
 bash.html.markdown | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 211d2944..bd2d5984 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -83,7 +83,7 @@ echo Hello, $Name!
 
 # We have the usual if structure:
 # use 'man test' for more info about conditionals
-if [ $Name -ne $USER ]
+if [ $Name != $USER ]
 then
     echo "Your name isn't your username"
 else
@@ -91,12 +91,12 @@ else
 fi
 
 # NOTE: if $Name is empty, bash sees the above condition as:
-if [ -ne $USER ]
+if [ != $USER ]
 # which is invalid syntax
 # so the "safe" way to use potentially empty variables in bash is:
-if [ "$Name" -ne $USER ] ...
+if [ "$Name" != $USER ] ...
 # which, when $Name is empty, is seen by bash as:
-if [ "" -ne $USER ] ...
+if [ "" != $USER ] ...
 # which works as expected
 
 # There is also conditional execution
-- 
cgit v1.2.3


From 4e5439c21f5ab5ba33e46926b2fc5e44e25362ae Mon Sep 17 00:00:00 2001
From: Viren Nadkarni <viren-nadkarni@users.noreply.github.com>
Date: Thu, 12 May 2016 16:37:50 +0530
Subject: Fix a mistake in fgrep example (#2254)

---
 bash.html.markdown | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index f3c9cccc..02d7f31e 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -270,7 +270,7 @@ grep "^foo.*bar$" file.txt
 grep -c "^foo.*bar$" file.txt
 # if you literally want to search for the string,
 # and not the regex, use fgrep (or grep -F)
-fgrep "^foo.*bar$" file.txt
+fgrep "foobar" file.txt
 
 
 # Read Bash shell builtins documentation with the bash 'help' builtin:
-- 
cgit v1.2.3


From d1216a4253c1b03641c10b171030d04227ad8408 Mon Sep 17 00:00:00 2001
From: Sachin Divekar <ssd532@gmail.com>
Date: Sun, 26 Jun 2016 18:08:05 +0530
Subject: Add an example of trap command  (#1826)

* Begin writing document for PCRE

Started writing learnxinyminutes document for PCRE to cover general purpose regular expressions.
Added introduction and a couple of details.

* Change introductory example for regex

The old example was incorrect. It's replaced with a simple one.

* Add some more introductory text

* Add first example

* Added more example and a table for proper formatting

* Add few more examples

* Formatting

* Improve example

* Edit description of character classes

* Add a way to test regex

Add https://regex101.com/ web application to test the regex provided in example.

* Add example of trap command

trap is a very important command to intercept a fatal signal, perform cleanup, and then exit gracefully. It needs an entry in this document.

Here a simple and most common example of using trap command i.e. cleanup upon receiving signal is added.

* Revert "Add example of trap command"

* Add an example of trap command

`trap` is a very important command to intercept a fatal signal, perform cleanup, and then exit gracefully. It needs an entry in this document.

Here a simple and most common example of using `trap` command i.e. cleanup upon receiving signal is added.
---
 bash.html.markdown | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 02d7f31e..c2c3e3f1 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -272,6 +272,9 @@ grep -c "^foo.*bar$" file.txt
 # and not the regex, use fgrep (or grep -F)
 fgrep "foobar" file.txt
 
+# trap command allows you to execute a command when a signal is received by your script.
+# Here trap command will execute rm if any one of the three listed signals is received.
+trap "rm $TEMP_FILE; exit" SIGHUP SIGINT SIGTERM
 
 # Read Bash shell builtins documentation with the bash 'help' builtin:
 help
-- 
cgit v1.2.3


From 8cd7c230aaa708dffb544887baa85de8f3377251 Mon Sep 17 00:00:00 2001
From: Jonathan Wang <jonathansw@outlook.com>
Date: Sun, 26 Jun 2016 09:04:11 -0400
Subject: [bash/en] basic parameter expansion, and brace expansion (#1533)

* Added brace expansion as well as basic parameter expansion

* frogot my name

* Update bash.html.markdown

 Added to parameter expansion
---
 bash.html.markdown | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index c2c3e3f1..a62bd167 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -11,6 +11,7 @@ contributors:
     - ["Rahil Momin", "https://github.com/iamrahil"]
     - ["Gregrory Kielian", "https://github.com/gskielian"]
     - ["Etan Reisner", "https://github.com/deryni"]
+    - ["Jonathan Wang", "https://github.com/Jonathansw"                       ]
 filename: LearnBash.sh
 ---
 
@@ -54,6 +55,13 @@ echo '$Variable'
 # its name without $. If you want to use the variable's value, you should use $.
 # Note that ' (single quote) won't expand the variables!
 
+# Parameter expansion ${ }:
+echo ${Variable}
+# This is a simple usage of parameter expansion
+# Parameter Expansion gets a value from a variable.  It "expands" or prints the value
+# During the expansion time the value or parameter are able to be modified
+# Below are other modifications that add onto this expansion
+
 # String substitution in variables
 echo ${Variable/Some/A}
 # This will substitute the first occurrence of "Some" with "A"
@@ -68,6 +76,12 @@ echo ${Foo:-"DefaultValueIfFooIsMissingOrEmpty"}
 # This works for null (Foo=) and empty string (Foo=""); zero (Foo=0) returns 0.
 # Note that it only returns default value and doesn't change variable value.
 
+# Brace Expansion { }
+# Used to generate arbitrary strings
+echo {1..10}
+echo {a..z}
+# This will output the range from the start value to the end value
+
 # Builtin variables:
 # There are some useful builtin variables, like
 echo "Last program's return value: $?"
-- 
cgit v1.2.3


From b16c7ee2d8b41b5db4f713360280c284ca9b1a80 Mon Sep 17 00:00:00 2001
From: Leo Rudberg <ljrudberg@gmail.com>
Date: Sun, 10 Jul 2016 02:04:08 -0500
Subject: [bash/en] Addition to bash (#2302)

* Added bash intro edits

* Fixed page header

* Finalizing updates

Implemented my changes in the main bash code chunk instead of as an out-of-code prologue

* Final touches

* Added citation for John and mkdir content

* Added removed original intro back in

* Update bash.html.markdown

Moved "hard way" link to top of article

Fixed spacing

Grouped `rm` commands

* Fixed typos
---
 bash.html.markdown | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 68 insertions(+), 1 deletion(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index a62bd167..b1a14bdb 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -11,7 +11,10 @@ contributors:
     - ["Rahil Momin", "https://github.com/iamrahil"]
     - ["Gregrory Kielian", "https://github.com/gskielian"]
     - ["Etan Reisner", "https://github.com/deryni"]
-    - ["Jonathan Wang", "https://github.com/Jonathansw"                       ]
+    - ["Jonathan Wang", "https://github.com/Jonathansw"]   
+    - ["Leo Rudberg", "https://github.com/LOZORD"]
+    - ["Betsy Lorton", "https://github.com/schbetsy"]
+    - ["John Detter", "https://github.com/jdetter"]
 filename: LearnBash.sh
 ---
 
@@ -20,6 +23,8 @@ Nearly all examples below can be a part of a shell script or executed directly i
 
 [Read more here.](http://www.gnu.org/software/bash/manual/bashref.html)
 
+Another recommened link: [The Command Line Crash Course](http://cli.learncodethehardway.org/book/)
+
 ```bash
 #!/bin/bash
 # First line of the script is shebang which tells the system how to execute
@@ -90,6 +95,21 @@ echo "Number of arguments passed to script: $#"
 echo "All arguments passed to script: $@"
 echo "Script's arguments separated into different variables: $1 $2..."
 
+# Now that we know how to echo and use variables,
+# let's learn some of the other basics of bash!
+
+# Getting our current directory is available through the command `pwd`.
+# `pwd` stands for "print working directory".
+# We can also use the builtin variable `$PWD`.
+# Observer that the following are equivalent:
+echo "I'm in $(pwd)" # execs `pwd` and interpolates output
+echo "I'm in $PWD" # interpolates the variable
+
+# If you get too much output in your terminal, or from a script, the command
+# `clear` clears your screen
+clear
+# Ctrl-L also works for clearing output
+
 # Reading a value from input:
 echo "What's your name?"
 read Name # Note that we didn't need to declare a new variable
@@ -138,12 +158,37 @@ ls
 
 # These commands have options that control their execution:
 ls -l # Lists every file and directory on a separate line
+ls -t # Sort the directory contents by last-modified date (descending)
+ls -R # Recursively `ls` this directory and all of its subdirectories
 
 # Results of the previous command can be passed to the next command as input.
 # grep command filters the input with provided patterns. That's how we can list
 # .txt files in the current directory:
 ls -l | grep "\.txt"
 
+# Use `cat` to print files to stdout:
+cat file.txt
+
+# We can also read the file using `cat`:
+Contents=$(cat file.txt)
+echo "START OF FILE\n$Contents\nEND OF FILE"
+
+# Use `cp` to copy files or directories from one place to another.
+# `cp` creates NEW versions of the sources,
+# so editing the copy won't affect the original (and vice versa).
+# Note that it will overwrite the destination if it already exists.
+cp srcFile.txt clone.txt
+cp -r srcDirectory/ dst/ # recursively copy
+
+# Look into `scp` or `sftp` if you plan on exchanging files between computers.
+# `scp` behaves very similarly to `cp`.
+# `sftp` is more interactive.
+
+# Use `mv` to move files or directories from one place to another.
+# `mv` is similar to `cp`, but it deletes the source.
+# `mv` is also useful for renaming files!
+mv s0urc3.txt dst.txt # sorry, l33t hackers...
+
 # Since bash works in the context of a current directory, you might want to 
 # run your command in some other directory. We have cd for changing location:
 cd ~    # change to home directory
@@ -152,6 +197,14 @@ cd ..   # go up one directory
 cd /home/username/Documents   # change to specified directory
 cd ~/Documents/..    # still in home directory..isn't it??
 
+# Use subshells to work across directories
+(echo "First, I'm here: $PWD") && (cd someDir; echo "Then, I'm here: $PWD")
+pwd # still in first directory
+
+# Use `mkdir` to create new directories.
+mkdir myNewDir
+# The `-p` flag causes new intermediate directories to be created as necessary.
+mkdir -p myNewDir/with/intermediate/directories
 
 # You can redirect command input and output (stdin, stdout, and stderr).
 # Read from stdin until ^EOF$ and overwrite hello.py with the lines
@@ -191,7 +244,9 @@ echo "#helloworld" | cat > output.out
 echo "#helloworld" | tee output.out >/dev/null
 
 # Cleanup temporary files verbosely (add '-i' for interactive)
+# WARNING: `rm` commands cannot be undone
 rm -v output.out error.err output-and-error.log
+rm -r tempDir/ # recursively delete
 
 # Commands can be substituted within other commands using $( ):
 # The following command displays the number of files and directories in the
@@ -282,6 +337,13 @@ sed -i 's/okay/great/g' file.txt
 grep "^foo.*bar$" file.txt
 # pass the option "-c" to instead print the number of lines matching the regex
 grep -c "^foo.*bar$" file.txt
+# Other useful options are:
+grep -r "^foo.*bar$" someDir/ # recursively `grep`
+grep -n "^foo.*bar$" file.txt # give line numbers
+grep -rI "^foo.*bar$" someDir/ # recursively `grep`, but ignore binary files
+# perform the same initial search, but filter out the lines containing "baz"
+grep "^foo.*bar$" file.txt | grep -v "baz"
+
 # if you literally want to search for the string,
 # and not the regex, use fgrep (or grep -F)
 fgrep "foobar" file.txt
@@ -290,6 +352,11 @@ fgrep "foobar" file.txt
 # Here trap command will execute rm if any one of the three listed signals is received.
 trap "rm $TEMP_FILE; exit" SIGHUP SIGINT SIGTERM
 
+# `sudo` is used to perform commands as the superuser
+$NAME1=$(whoami)
+$NAME2=$(sudo whoami)
+echo "Was $NAME1, then became more powerful $NAME2"
+
 # Read Bash shell builtins documentation with the bash 'help' builtin:
 help
 help help
-- 
cgit v1.2.3


From 527eab7108f4b5587f4a4afd9dad53ef0de2c565 Mon Sep 17 00:00:00 2001
From: Isaac Virshup <ivirshup@gmail.com>
Date: Fri, 16 Sep 2016 17:53:18 +1000
Subject: [bash/en] Remove link unavailable resource (#2372) (#2373)

Link pointed to a book which was not released. Fixes #2372.
---
 bash.html.markdown | 2 --
 1 file changed, 2 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index b1a14bdb..c5260915 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -23,8 +23,6 @@ Nearly all examples below can be a part of a shell script or executed directly i
 
 [Read more here.](http://www.gnu.org/software/bash/manual/bashref.html)
 
-Another recommened link: [The Command Line Crash Course](http://cli.learncodethehardway.org/book/)
-
 ```bash
 #!/bin/bash
 # First line of the script is shebang which tells the system how to execute
-- 
cgit v1.2.3


From 81975893a7c1ac2dbc4d0db0c16864d751f6c845 Mon Sep 17 00:00:00 2001
From: Tim Heaney <oylenshpeegul@gmail.com>
Date: Sun, 2 Oct 2016 13:16:12 -0400
Subject: Reword pwd comments (#2402)

Getting is redundant.
Observe, not observer.
---
 bash.html.markdown | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index c5260915..7b7a3eef 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -96,10 +96,10 @@ echo "Script's arguments separated into different variables: $1 $2..."
 # Now that we know how to echo and use variables,
 # let's learn some of the other basics of bash!
 
-# Getting our current directory is available through the command `pwd`.
+# Our current directory is available through the command `pwd`.
 # `pwd` stands for "print working directory".
 # We can also use the builtin variable `$PWD`.
-# Observer that the following are equivalent:
+# Observe that the following are equivalent:
 echo "I'm in $(pwd)" # execs `pwd` and interpolates output
 echo "I'm in $PWD" # interpolates the variable
 
-- 
cgit v1.2.3


From 9b2da0936507da307d2535f65a79a1161d4c2c11 Mon Sep 17 00:00:00 2001
From: Remigiusz Suwalski <remigiusz.suwalski@gmail.com>
Date: Thu, 13 Oct 2016 08:25:44 +0200
Subject: Removed excessive dollar signs (#2447)

There is no $ when one referencec the name of a variable as Bash is not PHP.
---
 bash.html.markdown | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 7b7a3eef..271ef62c 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -351,8 +351,8 @@ fgrep "foobar" file.txt
 trap "rm $TEMP_FILE; exit" SIGHUP SIGINT SIGTERM
 
 # `sudo` is used to perform commands as the superuser
-$NAME1=$(whoami)
-$NAME2=$(sudo whoami)
+NAME1=$(whoami)
+NAME2=$(sudo whoami)
 echo "Was $NAME1, then became more powerful $NAME2"
 
 # Read Bash shell builtins documentation with the bash 'help' builtin:
-- 
cgit v1.2.3


From 303de42a2c62193de9418ed5060ed5e99f26ba3a Mon Sep 17 00:00:00 2001
From: Rholais Lii <rholais@gmail.com>
Date: Sun, 12 Feb 2017 23:06:21 +0800
Subject: [bash/en-us]Fix spelling (#2654)

* Fix spelling

* Remove the contributor tag
---
 bash.html.markdown | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 271ef62c..14366e4c 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -156,7 +156,7 @@ ls
 
 # These commands have options that control their execution:
 ls -l # Lists every file and directory on a separate line
-ls -t # Sort the directory contents by last-modified date (descending)
+ls -t # Sorts the directory contents by last-modified date (descending)
 ls -R # Recursively `ls` this directory and all of its subdirectories
 
 # Results of the previous command can be passed to the next command as input.
-- 
cgit v1.2.3


From 96f62560ba5a7be6f2571656fa16f99446da87a0 Mon Sep 17 00:00:00 2001
From: Keith Miyake <keith.miyake@gmail.com>
Date: Fri, 29 Sep 2017 09:09:39 -0700
Subject: [bash/en] Provide example outputs for #549

---
 bash.html.markdown | 90 +++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 66 insertions(+), 24 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 14366e4c..76710aa8 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -30,59 +30,62 @@ Nearly all examples below can be a part of a shell script or executed directly i
 # As you already figured, comments start with #. Shebang is also a comment.
 
 # Simple hello world example:
-echo Hello world!
+echo Hello world! # => Hello world!
 
 # Each command starts on a new line, or after semicolon:
 echo 'This is the first line'; echo 'This is the second line'
+# => This is the first line
+# => This is the second line
 
 # Declaring a variable looks like this:
 Variable="Some string"
 
 # But not like this:
-Variable = "Some string"
+Variable = "Some string" # => returns error "Variable: command not found"
 # Bash will decide that Variable is a command it must execute and give an error
 # because it can't be found.
 
 # Or like this:
-Variable= 'Some string'
+Variable= 'Some string' # => returns error: "Some string: command not found"
 # Bash will decide that 'Some string' is a command it must execute and give an
 # error because it can't be found. (In this case the 'Variable=' part is seen
 # as a variable assignment valid only for the scope of the 'Some string'
 # command.)
 
 # Using the variable:
-echo $Variable
-echo "$Variable"
-echo '$Variable'
+echo $Variable # => Some string
+echo "$Variable" # => Some string
+echo '$Variable' # => Some string
 # When you use the variable itself — assign it, export it, or else — you write
 # its name without $. If you want to use the variable's value, you should use $.
 # Note that ' (single quote) won't expand the variables!
 
 # Parameter expansion ${ }:
-echo ${Variable}
+echo ${Variable} # => Some string
 # This is a simple usage of parameter expansion
 # Parameter Expansion gets a value from a variable.  It "expands" or prints the value
 # During the expansion time the value or parameter are able to be modified
 # Below are other modifications that add onto this expansion
 
 # String substitution in variables
-echo ${Variable/Some/A}
+echo ${Variable/Some/A} # => A string
 # This will substitute the first occurrence of "Some" with "A"
 
 # Substring from a variable
 Length=7
-echo ${Variable:0:Length}
+echo ${Variable:0:Length} # => Some st
 # This will return only the first 7 characters of the value
 
 # Default value for variable
-echo ${Foo:-"DefaultValueIfFooIsMissingOrEmpty"}
+echo ${Foo:-"DefaultValueIfFooIsMissingOrEmpty"} 
+# => DefaultValueIfFooIsMissingOrEmpty
 # This works for null (Foo=) and empty string (Foo=""); zero (Foo=0) returns 0.
 # Note that it only returns default value and doesn't change variable value.
 
 # Brace Expansion { }
 # Used to generate arbitrary strings
-echo {1..10}
-echo {a..z}
+echo {1..10} # => 1 2 3 4 5 6 7 8 9 10
+echo {a..z} # => a b c d e f g h i j k l m n o p q r s t u v w x y z
 # This will output the range from the start value to the end value
 
 # Builtin variables:
@@ -121,6 +124,7 @@ then
 else
     echo "Your name is your username"
 fi
+# True if the value of $Name is not equal to the current user's login username
 
 # NOTE: if $Name is empty, bash sees the above condition as:
 if [ != $USER ]
@@ -133,7 +137,11 @@ if [ "" != $USER ] ...
 
 # There is also conditional execution
 echo "Always executed" || echo "Only executed if first command fails"
+# => Always executed
 echo "Always executed" && echo "Only executed if first command does NOT fail"
+# => Always executed
+# => Only executed if first command does NOT fail
+
 
 # To use && and || with if statements, you need multiple pairs of square brackets:
 if [ "$Name" == "Steve" ] && [ "$Age" -eq 15 ]
@@ -147,12 +155,12 @@ then
 fi
 
 # Expressions are denoted with the following format:
-echo $(( 10 + 5 ))
+echo $(( 10 + 5 )) # => 15
 
 # Unlike other programming languages, bash is a shell so it works in the context
 # of a current directory. You can list files and directories in the current
 # directory with the ls command:
-ls
+ls # Lists the files and subdirectories contained in the current directory
 
 # These commands have options that control their execution:
 ls -l # Lists every file and directory on a separate line
@@ -169,7 +177,10 @@ cat file.txt
 
 # We can also read the file using `cat`:
 Contents=$(cat file.txt)
-echo "START OF FILE\n$Contents\nEND OF FILE"
+echo "START OF FILE\n$Contents\nEND OF FILE" # "\n" prints a new line character
+# => START OF FILE
+# => [contents of file.txt]
+# => END OF FILE
 
 # Use `cp` to copy files or directories from one place to another.
 # `cp` creates NEW versions of the sources,
@@ -203,6 +214,8 @@ pwd # still in first directory
 mkdir myNewDir
 # The `-p` flag causes new intermediate directories to be created as necessary.
 mkdir -p myNewDir/with/intermediate/directories
+# if the intermediate directories didn't already exist, running the above
+# command without the `-p` flag would return an error
 
 # You can redirect command input and output (stdin, stdout, and stderr).
 # Read from stdin until ^EOF$ and overwrite hello.py with the lines
@@ -217,12 +230,15 @@ for line in sys.stdin:
     print(line, file=sys.stdout)
 EOF
 
-# Run hello.py with various stdin, stdout, and stderr redirections:
-python hello.py < "input.in"
-python hello.py > "output.out"
-python hello.py 2> "error.err"
-python hello.py > "output-and-error.log" 2>&1
-python hello.py > /dev/null 2>&1
+# Run the hello.py Python script with various stdin, stdout, and 
+# stderr redirections:
+python hello.py < "input.in" # pass input.in as input to the script
+python hello.py > "output.out" # redirect output from the script to output.out
+python hello.py 2> "error.err" # redirect error output to error.err
+python hello.py > "output-and-error.log" 2>&1 # redirect both output and
+																						  # errors to output-and-error.log
+python hello.py > /dev/null 2>&1 # redirect all output and errors to 
+																 # the black hole, /dev/null, i.e., no output
 # The output error will overwrite the file if it exists,
 # if you want to append instead, use ">>":
 python hello.py >> "output.out" 2>> "error.err"
@@ -269,12 +285,19 @@ for Variable in {1..3}
 do
     echo "$Variable"
 done
+# => 1
+# => 2
+# => 3
+
 
 # Or write it the "traditional for loop" way:
 for ((a=1; a <= 3; a++))
 do
     echo $a
 done
+# => 1
+# => 2
+# => 3
 
 # They can also be used to act on files..
 # This will run the command 'cat' on file1 and file2
@@ -296,6 +319,7 @@ do
     echo "loop body here..."
     break
 done
+# => loop body here...
 
 # You can also define functions
 # Definition:
@@ -306,6 +330,11 @@ function foo ()
     echo "This is a function"
     return 0
 }
+# Call the function `foo` with two arguments, arg1 and arg2:
+foo arg1 arg2
+# => Arguments work just like script arguments: arg1 arg2
+# => And: arg1 arg2...
+# => This is a function
 
 # or simply
 bar ()
@@ -313,6 +342,8 @@ bar ()
     echo "Another way to declare functions!"
     return 0
 }
+# Call the function `bar` with no arguments:
+bar # => Another way to declare functions!
 
 # Calling your function
 foo "My name is" $Name
@@ -320,25 +351,35 @@ foo "My name is" $Name
 # There are a lot of useful commands you should learn:
 # prints last 10 lines of file.txt
 tail -n 10 file.txt
+
 # prints first 10 lines of file.txt
 head -n 10 file.txt
+
 # sort file.txt's lines
 sort file.txt
+
 # report or omit repeated lines, with -d it reports them
 uniq -d file.txt
+
 # prints only the first column before the ',' character
 cut -d ',' -f 1 file.txt
-# replaces every occurrence of 'okay' with 'great' in file.txt, (regex compatible)
+
+# replaces every occurrence of 'okay' with 'great' in file.txt
+# (regex compatible)
 sed -i 's/okay/great/g' file.txt
+
 # print to stdout all lines of file.txt which match some regex
 # The example prints lines which begin with "foo" and end in "bar"
 grep "^foo.*bar$" file.txt
+
 # pass the option "-c" to instead print the number of lines matching the regex
 grep -c "^foo.*bar$" file.txt
+
 # Other useful options are:
 grep -r "^foo.*bar$" someDir/ # recursively `grep`
 grep -n "^foo.*bar$" file.txt # give line numbers
 grep -rI "^foo.*bar$" someDir/ # recursively `grep`, but ignore binary files
+
 # perform the same initial search, but filter out the lines containing "baz"
 grep "^foo.*bar$" file.txt | grep -v "baz"
 
@@ -346,8 +387,9 @@ grep "^foo.*bar$" file.txt | grep -v "baz"
 # and not the regex, use fgrep (or grep -F)
 fgrep "foobar" file.txt
 
-# trap command allows you to execute a command when a signal is received by your script.
-# Here trap command will execute rm if any one of the three listed signals is received.
+# The trap command allows you to execute a command whenever your script 
+# receives a signal. Here, trap will execute `rm` if it receives any of the 
+# three listed signals.
 trap "rm $TEMP_FILE; exit" SIGHUP SIGINT SIGTERM
 
 # `sudo` is used to perform commands as the superuser
-- 
cgit v1.2.3


From 4f86cfaa4433a739b1aa9828138da0f61c664bcd Mon Sep 17 00:00:00 2001
From: Harry Mumford-Turner <harrymt@users.noreply.github.com>
Date: Mon, 2 Oct 2017 14:10:53 +0100
Subject: [bash/en] Fixed formatting for The Black Hole

- [x] I solemnly swear that this is all original content of which I am the original author
- [x] Pull request title is prepended with `[language/lang-code]`
- [x] Pull request touches only one file (or a set of logically related files with similar changes made)
- [x] Content changes are aimed at *intermediate to experienced programmers* (this is a poor format for explaining fundamental programming concepts)
- [x] If you've changed any part of the YAML Frontmatter, make sure it is formatted according to [CONTRIBUTING.md](https://github.com/adambard/learnxinyminutes-docs/blob/master/CONTRIBUTING.markdown)
  - [x] Yes, I have double-checked quotes and field names!
---
 bash.html.markdown | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 76710aa8..981d7a1e 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -15,6 +15,7 @@ contributors:
     - ["Leo Rudberg", "https://github.com/LOZORD"]
     - ["Betsy Lorton", "https://github.com/schbetsy"]
     - ["John Detter", "https://github.com/jdetter"]
+    - ["Harry Mumford-Turner", "https://github.com/harrymt"]
 filename: LearnBash.sh
 ---
 
@@ -235,10 +236,8 @@ EOF
 python hello.py < "input.in" # pass input.in as input to the script
 python hello.py > "output.out" # redirect output from the script to output.out
 python hello.py 2> "error.err" # redirect error output to error.err
-python hello.py > "output-and-error.log" 2>&1 # redirect both output and
-																						  # errors to output-and-error.log
-python hello.py > /dev/null 2>&1 # redirect all output and errors to 
-																 # the black hole, /dev/null, i.e., no output
+python hello.py > "output-and-error.log" 2>&1 # redirect both output and errors to output-and-error.log
+python hello.py > /dev/null 2>&1 # redirect all output and errors to the black hole, /dev/null, i.e., no output
 # The output error will overwrite the file if it exists,
 # if you want to append instead, use ">>":
 python hello.py >> "output.out" 2>> "error.err"
-- 
cgit v1.2.3


From 027e152dda5f26e2aa74f6739c21f9ca3a8a4fde Mon Sep 17 00:00:00 2001
From: Joyce Kung <thejoycekung@users.noreply.github.com>
Date: Fri, 13 Oct 2017 12:10:32 -0400
Subject: Fixed line 59 - printing

Using echo with ' ' means that the variable won't be expanded, so it should print the literal $Variable instead of some string.
---
 bash.html.markdown | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'bash.html.markdown')

diff --git a/bash.html.markdown b/bash.html.markdown
index 981d7a1e..0c097c27 100644
--- a/bash.html.markdown
+++ b/bash.html.markdown
@@ -56,7 +56,7 @@ Variable= 'Some string' # => returns error: "Some string: command not found"
 # Using the variable:
 echo $Variable # => Some string
 echo "$Variable" # => Some string
-echo '$Variable' # => Some string
+echo '$Variable' # => $Variable
 # When you use the variable itself — assign it, export it, or else — you write
 # its name without $. If you want to use the variable's value, you should use $.
 # Note that ' (single quote) won't expand the variables!
-- 
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