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Full Discussion: Script to change first line of files in directory
Top Forums Shell Programming and Scripting Script to change first line of files in directory Post 302653619 by agama on Saturday 9th of June 2012 03:31:48 PM
Old 06-09-2012
You only need the cd command in the if statement. Your directory is a relative path (doesn't start with a slant) and that is why it's erroring (there isn't a ./xxxx directory inside of the directory which you switched to earlier in the script.

You also are wasting effort copying the file back in your script (extra i/o adds to the latency).

Code:
#!/usr/bin/bash

# mol_filename2firstline_2.sh 
### unneeded cd "$1"

if ! cd "${1:-no-such-directory}"     # also quote on the off chance that something in the path has spaces
then
   echo "abort: could not switch to '$1' or parameter was missing"
   exit 1
fi

ls | while read f              # for *   doesn't handle filenames with spaces or large numbers of files. 
do
    [ ! -f "$f" ] && continue

    printf %s\\n "$f" >"$f.new"
    if ! sed '1d' "$f" >>"$f.new"
    then
        rm "$f.new"
    else
        mv "$f.new" "$f"
    fi
done

This User Gave Thanks to agama For This Post:
LMHmedchem
 

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LEARN ABOUT MOJAVE

osacompile

OSACOMPILE(1)						    BSD General Commands Manual 					     OSACOMPILE(1)

NAME

     osacompile -- compile AppleScripts and other OSA language scripts

SYNOPSIS

     osacompile [-l language] [-e command] [-o name] [-d] [-r type:id] [-t type] [-c creator] [-x] [-s] [-u] [-a arch] [file ...]

DESCRIPTION

     osacompile compiles the given files, or standard input if none are listed, into a single output script.  Files may be plain text or other
     compiled scripts.	The options are as follows:

     -l language
	   Override the language for any plain text files.  Normally, plain text files are compiled as AppleScript.

     -e command
	   Enter one line of a script.	Script commands given via -e are prepended to the normal source, if any.  Multiple -e options may be given
	   to build up a multi-line script.  Because most scripts use characters that are special to many shell programs (e.g., AppleScript uses
	   single and double quote marks, ``('', ``)'', and ``*''), the command will have to be correctly quoted and escaped to get it past the
	   shell intact.

     -o name
	   Place the output in the file name.  If -o is not specified, the resulting script is placed in the file ``a.scpt''.  The value of -o
	   partly determines the output file format; see below.

     -x    Save the resulting script as execute-only.

     The following options are only relevant when creating a new bundled applet or droplet:

     -s    Stay-open applet.

     -u    Use startup screen.

     -a arch
	   Create the applet or droplet for the specified target architecture arch.  The allowable values are ``ppc'', ``i386'', and ``x86_64''.
	   The default is to create a universal binary.

     The following options control the packaging of the output file.  You should only need them for compatibility with classic Mac OS or for cus-
     tom file formats.

     -d    Place the resulting script in the data fork of the output file.  This is the default.

     -r type:id
	   Place the resulting script in the resource fork of the output file, in the specified resource.

     -t type
	   Set the output file type to type, where type is a four-character code.  If this option is not specified, the creator code will not be
	   set.

     -c creator
	   Set the output file creator to creator, where creator is a four-character code.  If this option is not specified, the creator code will
	   not be set.

     If no options are specified, osacompile produces a Mac OS X format script file: data fork only, with no type or creator code.

     If the -o option is specified and the file does not already exist, osacompile uses the filename extension to determine what type of file to
     create.  If the filename ends with ``.app'', it creates a bundled applet or droplet.  If the filename ends with ``.scptd'', it creates a bun-
     dled compiled script.  Otherwise, it creates a flat file with the script data placed according to the values of the -d and -r options.

EXAMPLES

     To produce a script compatible with classic Mac OS:

	   osacompile -r scpt:128 -t osas -c ToyS example.applescript

SEE ALSO

     osascript(1), osalang(1)

Mac OS X							 November 12, 2008							  Mac OS X
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