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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 302975814 by Ra26k on Sunday 19th of June 2016 08:04:42 AM
Old 06-19-2016
Lightbulb Help on for loop in bash
Hi,

In the code "for loop" has been used to search for files (command line arguments) in directories and then produce the result to the standard output. However, I want when no files are named on the command line, it should read a list of files from standard input and it should use the command line arguments when given.

It can be done with "read" command by modifying the code, however, I am not able to make it work with both. I mean I want the code to work for both ways (reading standard input when no command line arguments are given and reading command line arguments when given).

Don't want to go for another block of "for loop" for both the conditions. Any suggestions would be highly appreciated.....Thanks.

Code:
#! /bin/sh
#
# Search for one or more ordinary files or file patterns on a search
# path defined by a specified environment variable.
#
# The output on standard output is normally either the full path
# to the first instance of each file found on the search path,
# or "filename: not found" on standard error.
#
# The exit code is 0 if all files are found, and otherwise a
# nonzero value equal to the number of files not found (subject
# to the shell exit code limit of 125).
#
# Usage:
# pathfind [--all] [--?] [--help] [--version] envvar pattern(s)
#
# With the --all option, every directory in the path is
# searched, instead of stopping with the first one found.

IFS='
'
OLDPATH="$PATH"
PATH=/bin:/usr/bin
export PATH
error( )
{
echo "$@" 1>&2
usage_and_exit 1
}

usage( )
{
echo "Usage: $PROGRAM [--all] [--?] [--help] [--version] envvar pattern(s)"
}

usage_and_exit( )
{
usage
exit $1
}

version( )
{
echo "$PROGRAM version $VERSION"
}

warning( )
{
echo "$@" 1>&2
EXITCODE=`expr $EXITCODE + 1`
}

all=no
envvar=
EXITCODE=0
PROGRAM=`basename $0`
VERSION=1.0

while test $# -gt 0
do
  case $1 in
	--all | --al | --a | -all | -al | -a )
	all=yes
	;;
	--help | --hel | --he | --h | '--?' | -help | -hel | -he | -h | '-?' )
	usage_and_exit 0
	;;
	--version | --versio | --versi | --vers | --ver | --ve | --v | \
	-version | -versio | -versi | -vers | -ver | -ve | -v )
	version
	exit 0
	;;
	-*)
	error "Unrecognized option: $1"
	;;
	*)
	break
	;;
  esac
  shift
done

envvar="$1"
test $# -gt 0 && shift
test "x$envvar" = "xPATH" && envvar=OLDPATH

dirpath=`eval echo '${'"$envvar"'}' 2>/dev/null | tr : ' ' `

# sanity checks for error conditions
if test -z "$envvar"
  then
  error Environment variable missing or empty
  elif test "x$dirpath" = "x$envvar"
  then
  error "Broken sh on this platform: cannot expand $envvar"
  elif test -z "$dirpath"
  then
  error Empty directory search path
  elif test $# -eq 0
  then
  exit 0
fi

# loop over argument files or patterns and directories in the search path

for pattern in "$@"
do
  result=
  for dir in $dirpath
  do
    for file in $dir/$pattern
    do
      if test -f "$file"
      then
      result="$file"
      echo $result
      test "$all" = "no" && break 2
      fi
    done
  done
  test -z "$result" && warning "$pattern: not found"
done

# Limit exit status to 125
test $EXITCODE -gt 125 && EXITCODE=125
exit $EXITCODE

 

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LEARN ABOUT LINUX

npm-run-script

NPM-RUN-SCRIPT(1)                                                                                                                NPM-RUN-SCRIPT(1)

NAME

       npm-run-script - Run arbitrary package scripts

SYNOPSIS

         npm run-script <command> [--silent] [-- <args>...]

         alias: npm run

DESCRIPTION

       This  runs  an  arbitrary  command  from  a  package's  "scripts" object.  If no "command" is provided, it will list the available scripts.
       run[-script] is used by the test, start, restart, and stop commands, but can be called directly, as well. When the scripts in  the  package
       are printed out, they're separated into lifecycle (test, start, restart) and directly-run scripts.

       As  of  `  https://blog.npmjs.org/post/98131109725/npm-2-0-0, you can use custom arguments when executing scripts. The special option -- is
       used by getopt https://goo.gl/KxMmtG to delimit the end of the options. npm will pass all the arguments  after  the  --  directly  to  your
       script:

         npm run test -- --grep="pattern"

       The arguments will only be passed to the script specified after npm run and not to any pre or post script.

       The  env  script  is a special built-in command that can be used to list environment variables that will be available to the script at run-
       time. If an "env" command is defined in your package, it will take precedence over the built-in.

       In addition to the shell's pre-existing PATH, npm run adds node_modules/.bin to the PATH provided to  scripts.  Any  binaries  provided  by
       locally-installed  dependencies  can  be used without the node_modules/.bin prefix. For example, if there is a devDependency on tap in your
       package, you should write:

         "scripts": {"test": "tap test/*.js"}

       instead of

         "scripts": {"test": "node_modules/.bin/tap test/*.js"}

       to run your tests.

       The actual shell your script is run within is platform dependent. By default, on Unix-like systems it is the /bin/sh command, on Windows it
       is    the    cmd.exe.     The    actual    shell    referred    to    by    /bin/sh    also    depends    on   the   system.    As   of   `
       https://github.com/npm/npm/releases/tag/v5.1.0 you can customize the shell with the script-shell configuration.

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       script  to use different behavior based on what subdirectory you're in, you can use the INIT_CWD environment variable, which holds the full
       path you were in when you ran npm run.

       npm run sets the NODE environment variable to the node executable with which npm is executed. Also, if the  --scripts-prepend-node-path  is
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SEE ALSO

       o npm help 7 scripts

       o npm help test

       o npm help start

       o npm help restart

       o npm help stop

       o npm help 7 config

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