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Top Forums Shell Programming and Scripting why double brackets for array loop? Post 302338958 by drl on Wednesday 29th of July 2009 10:48:19 AM
Old 07-29-2009
Hi.

Because
Code:
for (( ...

is the syntax for that statement.

The meaning of single and double parentheses is different. See man ksh or man bash ... cheers, drl
 

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ZIPGREP(1L)															       ZIPGREP(1L)

NAME
zipgrep - search files in a ZIP archive for lines matching a pattern SYNOPSIS
zipgrep [egrep_options] pattern file[.zip] [file(s) ...] [-x xfile(s) ...] DESCRIPTION
zipgrep will search files within a ZIP archive for lines matching the given string or pattern. zipgrep is a shell script and requires egrep(1) and unzip(1L) to function. Its output is identical to that of egrep(1). ARGUMENTS
pattern The pattern to be located within a ZIP archive. Any string or regular expression accepted by egrep(1) may be used. file[.zip] Path of the ZIP archive. (Wildcard expressions for the ZIP archive name are not supported.) If the literal filename is not found, the suffix .zip is appended. Note that self-extracting ZIP files are supported, as with any other ZIP archive; just specify the .exe suffix (if any) explicitly. [file(s)] An optional list of archive members to be processed, separated by spaces. If no member files are specified, all members of the ZIP archive are searched. Regular expressions (wildcards) may be used to match multiple members: * matches a sequence of 0 or more characters ? matches exactly 1 character [...] matches any single character found inside the brackets; ranges are specified by a beginning character, a hyphen, and an end- ing character. If an exclamation point or a caret (`!' or `^') follows the left bracket, then the range of characters within the brackets is complemented (that is, anything except the characters inside the brackets is considered a match). (Be sure to quote any character that might otherwise be interpreted or modified by the operating system.) [-x xfile(s)] An optional list of archive members to be excluded from processing. Since wildcard characters match directory separators (`/'), this option may be used to exclude any files that are in subdirectories. For example, ``zipgrep grumpy foo *.[ch] -x */*'' would search for the string ``grumpy'' in all C source files in the main directory of the ``foo'' archive, but none in any subdirectories. Without the -x option, all C source files in all directories within the zipfile would be searched. OPTIONS
All options prior to the ZIP archive filename are passed to egrep(1). SEE ALSO
egrep(1), unzip(1L), zip(1L), funzip(1L), zipcloak(1L), zipinfo(1L), zipnote(1L), zipsplit(1L) URL
The Info-ZIP home page is currently at http://www.info-zip.org/pub/infozip/ or ftp://ftp.info-zip.org/pub/infozip/ . AUTHORS
zipgrep was written by Jean-loup Gailly. Info-ZIP 20 April 2009 ZIPGREP(1L)
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