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Full Discussion: Help on for loop in bash
Top Forums Shell Programming and Scripting Help on for loop in bash Post 302976167 by MadeInGermany on Friday 24th of June 2016 12:37:41 PM
Old 06-24-2016
I see three alternatives:
1. Everything to a for loop
Code:
#!/bin/sh
if [ $# -gt 0 ]
then
  patterns="$@"
else
  patterns=`cat`
fi
set -f # no wildcard globbing for safety
for pattern in $patterns
do
  # loop code
  printf '%s\n' "$pattern"
done

If no argument is given, it loops over the words from stdin.
Unlike the following two solutions, where the while loop reads the lines from stdin.
2. Everything to a while loop (simpler than Don's solution)
Code:
#!/bin/sh
if [ $# -gt 0 ]
then
  printf '%s\n' "$@"
else
  cat
fi |
while IFS= read -r pattern
do
  # loop code
  printf '%s\n' "$pattern" 
done

3. separate for and while loops, common part in a function
Code:
#!/bin/sh
loop_code(){
   printf '%s\n' "$pattern"
}
if [ $# -gt 0 ]
then
  for pattern in "$@"
  do
    loop_code
  done
else
  while IFS= read -r pattern
  do
    loop_code
  done
fi

This User Gave Thanks to MadeInGermany For This Post:
Don Cragun
 

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LEARN ABOUT OPENDARWIN

fnmatch

FNMATCH(3)                                                   Linux Programmer's Manual                                                  FNMATCH(3)

NAME

       fnmatch - match filename or pathname

SYNOPSIS

       #include <fnmatch.h>

       int fnmatch(const char *pattern, const char *string, int flags);

DESCRIPTION

       The fnmatch() function checks whether the string argument matches the pattern argument, which is a shell wildcard pattern.

       The flags argument modifies the behavior; it is the bitwise OR of zero or more of the following flags:

       FNM_NOESCAPE
              If this flag is set, treat backslash as an ordinary character, instead of an escape character.

       FNM_PATHNAME
              If  this  flag  is  set,  match  a  slash  in  string only with a slash in pattern and not by an asterisk (*) or a question mark (?)
              metacharacter, nor by a bracket expression ([]) containing a slash.

       FNM_PERIOD
              If this flag is set, a leading period in string has to be matched exactly by a period in pattern.  A  period  is  considered  to  be
              leading if it is the first character in string, or if both FNM_PATHNAME is set and the period immediately follows a slash.

       FNM_FILE_NAME
              This is a GNU synonym for FNM_PATHNAME.

       FNM_LEADING_DIR
              If  this  flag (a GNU extension) is set, the pattern is considered to be matched if it matches an initial segment of string which is
              followed by a slash.  This flag is mainly for the internal use of glibc and is implemented only in certain cases.

       FNM_CASEFOLD
              If this flag (a GNU extension) is set, the pattern is matched case-insensitively.

       FNM_EXTMATCH
              If this flag (a GNU extension) is set, extended patterns are supported, as introduced by 'ksh' and now supported  by  other  shells.
              The extended format is as follows, with pattern-list being a '|' separated list of patterns.

       '?(pattern-list)'
              The pattern matches if zero or one occurrences of any of the patterns in the pattern-list match the input string.

       '*(pattern-list)'
              The pattern matches if zero or more occurrences of any of the patterns in the pattern-list match the input string.

       '+(pattern-list)'
              The pattern matches if one or more occurrences of any of the patterns in the pattern-list match the input string.

       '@(pattern-list)'
              The pattern matches if exactly one occurrence of any of the patterns in the pattern-list match the input string.

       '!(pattern-list)'
              The pattern matches if the input string cannot be matched with any of the patterns in the pattern-list.

RETURN VALUE

       Zero if string matches pattern, FNM_NOMATCH if there is no match or another nonzero value if there is an error.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       +----------+---------------+--------------------+
       |Interface | Attribute     | Value              |
       +----------+---------------+--------------------+
       |fnmatch() | Thread safety | MT-Safe env locale |
       +----------+---------------+--------------------+
CONFORMING TO

       POSIX.1-2001, POSIX.1-2008, POSIX.2.  The FNM_FILE_NAME, FNM_LEADING_DIR, and FNM_CASEFOLD flags are GNU extensions.

SEE ALSO

       sh(1), glob(3), scandir(3), wordexp(3), glob(7)

COLOPHON

       This  page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

GNU                                                                 2015-12-28                                                          FNMATCH(3)
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