-#!/usr/bin/env bash
-
-### Buffers and redirect ###
-
-#buffers 0=STDIN, 1=STDOUT, 2=STDERR, then 3 up to 9 are available for use
-
-#exec without command argument will redirect IO for current program e.g.
-#send stdout to /dev/null via file descriptor 9
-exec 9>/dev/null 1>&9
-#restore stdout so we can see it
-exec &>/dev/tty
-
-# example of redirect, get use to this //Gustav
-cat < my_file.txt > my_new_file.txt
-
-### Man pages ###
-
-man #regular man pages
-help #for help bash
-apropos #search man pages (man)
-
-### Symlinks and inodes ###
-
-readlink #shows symlink info, also see f flag
-
-#hardlink points to underlying inode so multiple can exist, and as long as any do exist the inode cannot be overwritten
-#hardlink cannot point to folder as this would create loops
-#however, symbolic (soft) links can point to folders since `readlink` shows the real path.
-
-
-#use `stat` to see amount of (hard) links to a file, and other such info
-stat
-readlink
-ln a b
-ln -s a b
-
-### Bash shortcuts ###
-
-#0th argument of last command
-echo !:0
-
-#return from last command ("error code") for C errors see errno
-echo $?
-
-
-### grep, sed, awk
-
-# grep, cut, wc can perform a lot of basic operations
-# sed seems to be good for a lot of things, e.g. search and replace stuff
- # example: find all headers (# ## ### etc) and add AS MANY # to the end of line
-# awk, a benefit here is that we can use variables and arrays to count and sum results, easily maintain data over multiple lines
-
-### SED append corresponding nr of '#' ###
-
-#save starting '#' (at least 1) to group and append last to line
-#s/ for search and replace
-#\) group hits for later use as \1 and \2 ('#' and rest of text)
-#Note that spaces have a meaning for the matching
-#find rows starting with AT LEAST one '#' and save as first group, rest '.*' (all chars) to the end of row ($) save as second group. Finally the text is printed as \1 \2 \1, i.e. the starting '#' are repeated at the end.
-
-sed -i -E "s/^(#+)(.*)$/\1\2 \1/" example_doc.txt
-sed -i -E "s/^\(##*\)\(.*\)$/\1\2 \1/" example_doc.txt
-
-
-### Find users with bash as shell ###
-
-#use cut to get first word before delimiter :
-grep "/bin/bash" /etc/passwd | cut -d \: -f 1
-
-#find lines ending with 'bash', each hit perform search and replace
-sed -E "/.*bash$/ { s/^(\w*).*$/\1/;p };d" < /etc/passwd
-
-#set separator ':', match regex, and print first string (before separator)
-awk -F: '/bash/{ print $1 }' < /etc/passwd
-
-
-### Lines without word ###
-
-grep -v "daemon" /etc/group
-
-sed -E "/daemon/d" < /etc/group
-
-awk '!/daemon/' < /etc/group
-
-
-### Count hits and show relevant lines ###
-
-#print matching lines numbers
-awk '/localhost/{print "Line " NR " matches"}' < /etc/hosts
-
-# Count nr of hits (i) and matching line numbers (NR)
-# TODO this seems broken!
-#awk '/localhost/{i=0}{i++} /localhost/{print "Line " NR " matches"} END {print i " hits"}' < /etc/hosts
-
-
-### List files with numbers (exclude folders) ###
-
-#ls -p to list folders with / at the end
-ls -p /etc/ | grep -v ".*/$"| grep "[0-9]"
-
-ls -p /etc/ | awk "! /.*\/$/ && /[0-9]/"
-
-#delete lines ending in /, then print lines containing at least a number, delete all lines
-ls -p /etc/ |sed -E "/\/$/ d; /[0-9]/ p; d"
-
-
-### SUM variables with awk ###
-
-#If third argument delimted by : only contains digits add it to sum
-awk -F ':' '$3 ~ /^[0-9]+$/ {sum+=$3} END {print sum}' < /etc/passwd
-
-### AWK DIV ###
-
-#BEGIN {
-# # Things to be done before you start processing rows.
-#}
-#{
-# # Things to be done for each row.
-#}
-#END {
-# # Things to be done after processing the last row.
-#}
-
-
-### Div ###
-
-#simple find exact filename
-ls /usr/share/doc -R | grep "^README$"
+ #!/usr/bin/env bash
+
+ ### Buffers and redirect ###
+
+ #buffers 0=STDIN, 1=STDOUT, 2=STDERR, then 3 up to 9 are available for use
+
+ #exec without command argument will redirect IO for current program e.g.
+ #send stdout to /dev/null via file descriptor 9
+ exec 9>/dev/null 1>&9
+ #restore stdout so we can see it
+ exec &>/dev/tty
+
+ # example of redirect, get use to this //Gustav
+ cat < my_file.txt > my_new_file.txt
+
+ ### Man pages ###
+
+ man #regular man pages
+ help #for help bash
+ apropos #search man pages (man)
+
+ ### Symlinks and inodes ###
+
+ readlink #shows symlink info, also see f flag
+
+ #hardlink points to underlying inode so multiple can exist, and as long as any do exist the inode cannot be overwritten
+ #hardlink cannot point to folder as this would create loops
+ #however, symbolic (soft) links can point to folders since `readlink` shows the real path.
+
+
+ #use `stat` to see amount of (hard) links to a file, and other such info
+ stat
+ readlink
+ ln a b
+ ln -s a b
+
+ ### Bash shortcuts ###
+
+ #0th argument of last command
+ echo !:0
+
+ #return from last command ("error code") for C errors see errno
+ echo $?
+
+
+ ### grep, sed, awk
+
+ # grep, cut, wc can perform a lot of basic operations
+ # sed seems to be good for a lot of things, e.g. search and replace stuff
+ # example: find all headers (# ## ### etc) and add AS MANY # to the end of line
+ # awk, a benefit here is that we can use variables and arrays to count and sum results, easily maintain data over multiple lines
+
+ ### SED append corresponding nr of '#' ###
+
+ #save starting '#' (at least 1) to group and append last to line
+ #s/ for search and replace
+ #\) group hits for later use as \1 and \2 ('#' and rest of text)
+ #Note that spaces have a meaning for the matching
+ #find rows starting with AT LEAST one '#' and save as first group, rest '.*' (all chars) to the end of row ($) save as second group. Finally the text is printed as \1 \2 \1, i.e. the starting '#' are repeated at the end.
+
+ sed -i -E "s/^(#+)(.*)$/\1\2 \1/" example_doc.txt
+ sed -i -E "s/^\(##*\)\(.*\)$/\1\2 \1/" example_doc.txt
+
+
+ ### Find users with bash as shell ###
+
+ #use cut to get first word before delimiter :
+ grep "/bin/bash" /etc/passwd | cut -d \: -f 1
+
+ #find lines ending with 'bash', each hit perform search and replace
+ sed -E "/.*bash$/ { s/^(\w*).*$/\1/;p };d" < /etc/passwd
+
+ #set separator ':', match regex, and print first string (before separator)
+ awk -F: '/bash/{ print $1 }' < /etc/passwd
+
+
+ ### Lines without word ###
+
+ grep -v "daemon" /etc/group
+
+ sed -E "/daemon/d" < /etc/group
+
+ awk '!/daemon/' < /etc/group
+
+
+ ### Count hits and show relevant lines ###
+
+ #print matching lines numbers
+ awk '/localhost/{print "Line " NR " matches"}' < /etc/hosts
+
+ # Count nr of hits (i) and matching line numbers (NR)
+ # TODO this seems broken!
+ #awk '/localhost/{i=0}{i++} /localhost/{print "Line " NR " matches"} END {print i " hits"}' < /etc/hosts
+
+
+ ### List files with numbers (exclude folders) ###
+
+ #ls -p to list folders with / at the end
+ ls -p /etc/ | grep -v ".*/$"| grep "[0-9]"
+
+ ls -p /etc/ | awk "! /.*\/$/ && /[0-9]/"
+
+ #delete lines ending in /, then print lines containing at least a number, delete all lines
+ ls -p /etc/ |sed -E "/\/$/ d; /[0-9]/ p; d"
+
+
+ ### SUM variables with awk ###
+
+ #If third argument delimted by : only contains digits add it to sum
+ awk -F ':' '$3 ~ /^[0-9]+$/ {sum+=$3} END {print sum}' < /etc/passwd
+
+ ### AWK DIV ###
+
+ #BEGIN {
+ # # Things to be done before you start processing rows.
+ #}
+ #{
+ # # Things to be done for each row.
+ #}
+ #END {
+ # # Things to be done after processing the last row.
+ #}
+
+
+ ### Div ###
+
+ #simple find exact filename
+ ls /usr/share/doc -R | grep "^README$"
projects / inbyggd-frihet-wiki.git / commitdiff