Advanced Shell Operations
From Free Knowledge Base- The DUCK Project: information for everyone
. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
. @@ Example shell scripts useful for many tasks and provided by the community @@
. @@ Sat Jun 2 12:22:22 CDT 2001 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
. @@ Guide to Advanced Shell Operations @@@@@ shell script examples @@@@@@@@@@@@@
. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
.
. @ discard the output of a command @
.
. command > dev/null # eliminates output of STDOUT
.
. command > /dev/null 2>&1 # redirects STDERR to STDOUT and
. eliminates them
.
. @ use the value of a shell variable in a sed command @
.
. sed "/$DEL/d" file1 > file2 # deletes lines in file1 containing
. the value of $DEL
.
. @ check to see whether a variable has a value @
.
. if [ -z "$VAR" ] ; then list ; fi # list is the command that executes if
. $VAR doesn't have a value
.
. @ determine the full pathname of a directory @
.
. FULLPATH=`(cd dir ; pwd)` # determine full path of directory
.
. @ determine the full pathname of a file @
.
. CURDIR=`pwd` # save current directory path
. cd `dirname file` # change to directory with the file
. FULLPATH="`pwd`/`basename file`" # join output of pwd and filename
. cd $CURDIR # go back to the original directory
.
. @ rename all the *.html files to *.php in a directory @
.
. OLDSUFFIX=html # variable with old suffix
. NEWSUFFIX=php # variable with new suffix
. for FILE in *."$OLDSUFFIX" # all files that start with old suffix
. do
. NEWNAME=`echo "$FILE" | sed -e "s/${OLDSUFFIX}\$/$NEWSUFFIX/"`
. mv "$FILE" "$NEWFILE" # sed does a replace and then mv
. done # to move the files
.
. @ rename all the *.html files to *.htm using bash pattern matching @
.
. for i in *.html; do
. if [ -f ${i%l} ]; then
. echo ${i%l} already exists
. else
. mv $i ${i%l}
. fi
. done
.
. @ rename all default* files to index* @
.
. OLDPREFIX=default # variables with old and new prefix
. NEWPREFIX=index # for loop for all files with prefix
. for FILE in "$OLDPREFIX"* # sed -e for script, s for substitute
. do # carrot indicates start of line
. NEWNAME=`echo "$FILE" | sed -e "s/^${OLDPREFIX}/$NEWPREFIX/"`
. mv "$FILE" "$NEWNAME"
. done # rename the file and exit loop
.
. @ rename variations, example removes Shortcut to from beginning of files @
.
. OLD="Shortcut to "; NEW=""; for FILE in "$OLD"*; do; NEWNAME=`echo "$FILE" | sed -e "s/^${OLD}/$NEW/"`; mv "$FILE" "$NEWNAME";
. # places everything from above script
. on a single line, does a substitute
.
. OLD="Shortcut to "; for FILE in "$OLD"*; do NEWNAME=`echo "$FILE" | sed -e "s/^${OLD}//"`; mv "$FILE" "$NEWNAME"; echo "$NEWNAM
. # since it is not a substitute, this
. uses 1 variable but still echos each
. file as it is processed
.
. OLD="Shortcut to "; for FILE in "$OLD"*; do NEWNAME=`echo "$FILE" | sed -e "s/^${OLD}//"`; mv "$FILE" "$NEWNAME"; done
. # eliminate unecessary echo of filename
.
. for FILE in "Shortcut to "*; do N=`echo "$FILE" | sed -e "s/^Shortcut\ to\ //"`; mv "$FILE" "$N"; done
. # shortest method, eliminates use of
. variables and filename echo
.
. @ set all filenames in a directory to lowercase @
.
. for FILE in * # use mv -i to avoid overwriting files
. do # uses the tr command to convert case
. mv -i "$FILE" `echo "$FILE" | tr '[A-Z]' '[a-z]'` 2> /dev/null
. done
.
. @ eliminate msdos carriage returns in files @
.
. # dos uses \r\n (^M) where UNIX uses
. only \n
. tr -d '\015' < file1 > file2 # file1 contains carriage returns, file2
. is created without carriage returns
. # the \015 is oct representation of dos
. carriage returns
.
. -new entries-
.
. @ search and replace a text string with another in multiple files @
.
. for e in *; do mv $e $e.tmp ; sed 's/STRING1/STRING2/g' <$e.tmp >$e ; rm -f $e.tmp ; done
.
. (works best in a directory without subdirectories; it does bad things to subdirectories)
.
. @ replace a text string with another in files and recurse into directories @
.
. for e in `find . -type f`; do mv $e $e.tmp ; sed 's/STRING1/STRING2/g' <$e.tmp >$e ; rm -f $e.tmp ; done
.
. @ test to see if a file exists and print true if it does
.
. if test -e /tmp/seclog.pid ; then echo "true"; fi
.
. -lazygirl 4/29/2002
.
. @ remove text from within filenames in a directory of files. @
.
. All these files have a text string in the middle of their filename. The text we want to remove from
. within the file is: WEB.x264-video.
. so the file lexS01E01.WEB.x264-video.avi needs to change to lexS01E01.avi and the periods need escaped out
.
. for file in *; do mv "${file}" "${file/WEB\.x264-video\./}"; done
.
. @ replace linux line feeds in file containing a LF delimited list with a comma
. and space single line list. (file had space between last char and LF) @
.
. sed 's/.$/,\ /g' < parseme.txt > tmpfile.txt; tr -d '\012' < tmpfile.txt > outfile.txt
.
. -lazygirl 8/23/2004
.
. @ compare IP address to C block and if it is part of that network @
.
. host24=${ipaddress%.*}
. if [ "${host24}" = "192.168.30" ]; then
. echo "${ipaddress}";
. fi
.
. -Sun Nov 14 15:30:55 CST 2004
.
. @ useful 'c' like FOR loop (for/next) for bash @
.
. for i in `seq 0 99`;
. do
. echo number $i
. done
.
. -krissyj Dec 2004
.
. @ unzip a directory of zip files all at once @
.
. for FILE in *.zip; do unzip "$FILE"; done
.
. @ convert list of usernames into delete user shell script @
.
. :1,$s/^\(.*\)/userdel -r \1/
.
. @ live active monitoring of tcp connections from the shell @
.
. while $x <> 1; do
. clear
. echo "Current TCP connections for robotz.com"
. netstat -np|grep "tcp\ ";
. sleep 15s
. done
.
. @ old fashioned replace text string for every file in directory @
.
. change string1 to string2 in every file within the directory
.
. for e in *; do sed 's/<string1>/<string2>/g' $e >$e.tmp; rm -f $e; mv $e.tmp $e; done
.
. @ strip HTML tags out of a text/html file. This works unless a tag is split @
. and ends on the following line, such as long a href tags
.
. e=index.html; sed 's/<[^>]*>//g' $e >$e.tmp; mv $e.tmp $e
.
. @ prepend text- to the beginning of all JPG files in a directory @
.
. for f in *.JPG; do mv "$f" "text-$f"; done
Related Pages
If what you're looking for isn't on this page, try some of these related pages:
- Console Command Examples
- Console Command Reference
- Advanced Shell Operations
- How Do I: A Linux Q&A
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