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Shell Programming and Scripting
Check for file existence using wildcards
Post 302363098 by Azhrei on Monday 19th of October 2009 11:27:44 AM
10-19-2009
Thanks for replying and including the solution you ended up using. 
Btw, that looks like C shell code due to the redirection syntax. You really don't want to use the C shell for any kind of production work; it's too buggy and idiosyncratic. Google for "101 reasons not to use the C shell".
A problem with both my code and yours is the assumption that the current directory is readable and thus ls(1) won't fail due to anything other than a wildcard not being replaced by the shell. In the real world this is a reasonable assumption, but truly defensive shell scripting would check for that with and additional if statement of [ -r . ]
Because both of our routines use ls(1) they pay a performance penalty for the fork() and exec() required to run ls(1). If all built-in commands could be used it would be much faster.
For example, using for i in *.[Ll][Aa][Ss]; do break; done would result in the wildcard being expanded but the loop breaking the very first time through. The value of i will either be a real filename (as the wildcard was expanded) or the string *.[Ll][Aa][Ss] and a simple [ -e "$i" ] will determine that. This solution requires no fork/exec and will be much faster.
But I'm betting that the performance is not a big issue anyway.
Btw, that looks like C shell code due to the redirection syntax. You really don't want to use the C shell for any kind of production work; it's too buggy and idiosyncratic. Google for "101 reasons not to use the C shell".
A problem with both my code and yours is the assumption that the current directory is readable and thus ls(1) won't fail due to anything other than a wildcard not being replaced by the shell. In the real world this is a reasonable assumption, but truly defensive shell scripting would check for that with and additional if statement of [ -r . ]
Because both of our routines use ls(1) they pay a performance penalty for the fork() and exec() required to run ls(1). If all built-in commands could be used it would be much faster.
For example, using for i in *.[Ll][Aa][Ss]; do break; done would result in the wildcard being expanded but the loop breaking the very first time through. The value of i will either be a real filename (as the wildcard was expanded) or the string *.[Ll][Aa][Ss] and a simple [ -e "$i" ] will determine that. This solution requires no fork/exec and will be much faster.
But I'm betting that the performance is not a big issue anyway.
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paps
PAPS(1) General Commands Manual PAPS(1) NAME
paps - UTF-8 to PostScript converter using Pango SYNOPSIS
paps [options] files... DESCRIPTION
paps reads a UTF-8 encoded file and generates a PostScript language rendering of the file. The rendering is done by creating outline curves through the pango ft2 backend. OPTIONS
These programs follow the usual GNU command line syntax, with long options starting with two dashes (`-'). A summary of options is included below. --landscape Landscape output. Default is portrait. --columns=cl Number of columns output. Default is 1. --font=desc Set the font description. Default is Monospace 12. --rtl Do rtl layout. --paper ps Choose paper size. Known paper sizes are legal, letter, a4. Default is A4. --bottom-margin=bm Set bottom margin in postscript points (1/72 inch). Default is 36. --top-margin=tm Set top margin. Default is 36. --left-margin=lm Set left margin. Default is 36. --right-margin=rm Set right margin. Default is 36. --help Show summary of options. --header Draw page header for each page. --markup Interpret the text as pango markup. --encoding=ENCODING Assume the documentation encoding is ENCODING. --lpi Set the lines per inch. This determines the line spacing. --cpi Set the characters per inch. This is an alternative method of specifying the font size. --stretch-chars Indicates that characters should be stretched in the y-direction to fill up their vertical space. This is similar to the texttops behaviour. AUTHOR
paps was written by Dov Grobgeld <dov.grobgeld@gmail.com>. This manual page was written by Lior Kaplan <kaplan@debian.org>, for the Debian project (but may be used by others). April 17, 2006 PAPS(1)