1. Shell scripting From single commands to a shell script
Eth-0 zomer 2010
Wieringerwerf
10 Augustus
Marcel Nijenhof

2. Shell Scripting?

3. Marcel Nijenhof Nllgg Chairman 10 Year Board member LPI Nederland
Proctor
Proxy
Employee
Unix administrator

4. The script

5. Single commands $ mv file1 file1_20100416 $ mv file2 file2_20100416

6. The first script #!/bin/sh mv file1 file1_20100416

7. #!/bin/sh for f in file1 file2 file3 do mv "${f}" "${f}_20100416" done
Why no loop?
#!/bin/sh
for f in file1 file2 file3 do
mv "${f}" "${f}_ "
done

8. #!/bin/sh for f in file* do mv "${f}" "${f}_20100416" done
Using a wild card!
#!/bin/sh
for f in file* do
mv "${f}" "${f}_ "
done

9. ren file* #!/bin/sh for f in "$@" do mv "${f}" "${f}_20100416" done
Why hard code the names?
ren file*
#!/bin/sh
for f in do
mv "${f}" "${f}_ "
done

10. Dynamical extensions ren _20100808 file* #!/bin/sh APPEND=$1 shift
for f in do
mv "${f}" "${f}${APPEND}"
done

11. But i want capitals #!/bin/sh for f in "$@" do mv "${f}" "${f^^}" Done
Note: "${f^^}" is a bash version 4 option for bash 3 and posix use: $(echo "${f}" | tr "[a-z]" "[A-Z]")

12. How to combine #!/bin/sh if [ "$1" = -a ] then
APPEND=$ # ren -a _ file*
shift 2
else
Shift # ren * fi
for f in do
if [ "${APPEND}" ]
mv "${f}" "${f}${APPEND}"
mv "${f}" "${f^^}"
done

13. Using getopts ... while [ "$ARG" != "?" ] do getopts :a:u
case "$ARG" in a)
APPEND=${OPTARG} ;; u)
APPEND="" ?)
shift $((OPTIND-1))
break
esac
done

14. All options of the final script
ren: [-X] [-H] [-V] [-n] [-i] [-lu] [-p <PRE>] [-a <APPEND>] [-s <SEARCH>]
[-r <REPLACE>] <file list>
-X: Debug
-H: Help
-V: Version
-n: Don't rename files only show how files are renamed
-i: Interactive to prevent overwriting
-l: Change names to lower case
-u: Change names to upper case
-p <PREPEND>: Prepand <PREPEND> to the file names
-a <APPEND>: Append <APPEND> to the file names
-s <SEARCH>: Search the string in the filename
-r <REPLACE>: Replace the search part in the filename
<file list>: List of files to rename
Select only one of the options:
-l, -u, -p -a, -s
Example
ren -s DATE -r *.DATE

15. General structure Initialisation Getopts Check of the options
Rename loop
Check if file exist
Generate the new name
Check name change
Rename

16. Check options if [ -z "${CMD}" ] then echo "${CMD_ERROR}" >&2
exit 1 fi
if [ "${REPLACE}" -a "${CMD}" != SEARCH ]
echo "ERROR: Replace is only valid with search" >&2
if [ "$#" -le 0 ]
echo "ERROR: No file list" >&2

17. New file name case "${CMD}" in ... ;; LOWER) newfile="${file,,}"
SEARCH)
newfile="${file/${SEARCH}/${REPLACE}}" *)
echo "ERROR: No such command: ${CMD}" >&2
exit 2
esac
Note: "${file/${SEARCH}/${REPLACE}}" is een bash optie Voor posix: $(echo "${file}" | sed "s/${SEARCH}/${REPLACE}/")

18. Main loop for file in "$@" do if [ -f "${file}" ] then Nieuwe filenaam
[ "${file}" != "${newfile}" ]\
&& ${SHOW} mv ${MV_ARGS} \
"${file}" "${newfile}"
else
echo "ERROR: File not found:
${file}" >&2 fi
done

19. Het volledige script

20. Questions

21. Presentation Presentation: http://pion.xs4all.nl/lezingen/
ShellScripting_eth-0_2010.odp
ShellScripting_eth-0_2010.pdf
ren
Ren-posix
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