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Full Discussion: Looping through input/output
Top Forums UNIX for Beginners Questions & Answers Looping through input/output Post 302979883 by Don Cragun on Saturday 20th of August 2016 09:46:46 PM
Old 08-20-2016
I apologize for guessing wrong at what combining.executable does. I made the unwarranted assumption that a file named infile1 would be your 1st input file and that a file named infile2 would be your second input file instead of infile1 being the name of your 2nd input file and infile2 being the name of your 1st input file.

With that list of files and no indication of what produced it, I'll make another wild assumption that the list is the first couple of lines of output from the command:
Code:
ls *header

and that the intent is that your input files are to be processed in increasing alphanumeric sorted order. Assuming that is correct (which based on the failure of my earlier assumptions is certainly not guaranteed), the following will combine your input files and produce an output file named outfile. It uses temporary files named 0 and 1 and renames the last used temporary file to be outfile and removes the other temporary file before it exits:
Code:
#!/bin/ksh
i=0
last=0
for file in *header
do	case "$i" in
	(0)	f1=$file
		i=1
		;;
	(1)	combining.executable "$file" "$f1" > $((out = last))
		i=2
		;;
	(2)	out=$((1 - last))
		combining.executable "$file" $last > $out
		last=$out
		;;
	esac
done
mv $out "outfile"
rm -f $((1 - out))

Although written and tested using a Korn shell, this will work with any shell that uses basic Bourne shell syntax and supports POSIX arithmetic substitutions (such as ash, bash, dash, and ksh; but not csh and its derivatives, and not a traditional Bourne shell).
 

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LEARN ABOUT DEBIAN

esfilter

ESFILTER:(1)							   User Commands						      ESFILTER:(1)

NAME

       esfilter - Output a filtered or truncated version of a ES

SYNOPSIS

       esfilter [actions/switches] <infile> <outfile>

DESCRIPTION

	      TS tools version 1.11, esfilter built Nov 11 2008 17:15:39

	      Output a filtered or truncated version of an elementary stream.  The input is either H.264 (MPEG-4/AVC) or H.262 (MPEG-2).  The out-
	      put is either an elementary stream, or an H.222 transport stream

	      If output is to an H.222 Transport Stream, then fixed values for the PMT PID (0x66) and video PID (0x68) are used.

   Files:
       <infile>
	      is the input elementary stream (but see -stdin below).

	      <outfile> is the output stream, either an equivalent elementary

	      stream, or an H.222 Transport Stream (but see -stdout and -host below).

   Actions:
       -copy  Copy the input data to the output file (mostly useful as a way of truncating data with -max)

       -filter
	      Filter data from input to output, aiming to keep every <n>th frame (where <n> is specified by -freq).

       -strip For H.264, output just the IDR and I pictures, for H.262, output just the I pictures, but see -allref below.

   Switches:
       -verbose, -v
	      Output extra (debugging) messages

       -quiet, -q
	      Only output error messages

       -stdin Take input from <stdin>, instead of a named file

       -stdout
	      Write output to <stdout>, instead of a named file Forces -quiet.

       -host <host>, -host <host>:<port>
	      Writes output (over TCP/IP) to the named <host>, instead of to a named file. If <port> is not specified, it defaults to 88.  Implies
	      -tsout.

       -max <n>, -m <n>
	      Maximum number of frames to read (for -filter and -strip), or ES units/NAL units (for -copy).

       -freq <n>
	      Specify the frequency of frames to try to keep with -filter. Defaults to 8.

       -allref
	      With -strip, keep all reference pictures (H.264) or all I and P pictures (H.262)

       -tsout Output data as Transport Stream PES packets (the default is as Elementary Stream)

       -pes, -ts
	      The input file is TS or PS, to be read via the PES->ES reading mechanisms. Not allowed with -stdin.

   Stream type:
	      If input is from a file, then the program will look at the start of the file to determine if the stream is H.264 or H.262 data. This
	      process may occasionally come to the wrong conclusion, in which case the user can override the choice using the following switches.

	      If input is from standard input (via -stdin), then it is not possible for the program to make its own decision on the  input  stream
	      type.  Instead, it defaults to H.262, and relies on the user indicating if this is wrong.

       -h264, -avc
	      Force the program to treat the input as MPEG-4/AVC.

       -h262  Force the program to treat the input as MPEG-2.

	      TS tools version 1.11, esfilter built Nov 11 2008 17:15:39

	      Output a filtered or truncated version of an elementary stream.  The input is either H.264 (MPEG-4/AVC) or H.262 (MPEG-2).  The out-
	      put is either an elementary stream, or an H.222 transport stream

	      If output is to an H.222 Transport Stream, then fixed values for the PMT PID (0x66) and video PID (0x68) are used.

   Files:
       <infile>
	      is the input elementary stream (but see -stdin below).

	      <outfile> is the output stream, either an equivalent elementary

	      stream, or an H.222 Transport Stream (but see -stdout and -host below).

   Actions:
       -copy  Copy the input data to the output file (mostly useful as a way of truncating data with -max)

       -filter
	      Filter data from input to output, aiming to keep every <n>th frame (where <n> is specified by -freq).

       -strip For H.264, output just the IDR and I pictures, for H.262, output just the I pictures, but see -allref below.

   Switches:
       -verbose, -v
	      Output extra (debugging) messages

       -quiet, -q
	      Only output error messages

       -stdin Take input from <stdin>, instead of a named file

       -stdout
	      Write output to <stdout>, instead of a named file Forces -quiet.

       -host <host>, -host <host>:<port>
	      Writes output (over TCP/IP) to the named <host>, instead of to a named file. If <port> is not specified, it defaults to 88.  Implies
	      -tsout.

       -max <n>, -m <n>
	      Maximum number of frames to read (for -filter and -strip), or ES units/NAL units (for -copy).

       -freq <n>
	      Specify the frequency of frames to try to keep with -filter. Defaults to 8.

       -allref
	      With -strip, keep all reference pictures (H.264) or all I and P pictures (H.262)

       -tsout Output data as Transport Stream PES packets (the default is as Elementary Stream)

       -pes, -ts
	      The input file is TS or PS, to be read via the PES->ES reading mechanisms. Not allowed with -stdin.

   Stream type:
	      If input is from a file, then the program will look at the start of the file to determine if the stream is H.264 or H.262 data. This
	      process may occasionally come to the wrong conclusion, in which case the user can override the choice using the following switches.

	      If input is from standard input (via -stdin), then it is not possible for the program to make its own decision on the  input  stream
	      type.  Instead, it defaults to H.262, and relies on the user indicating if this is wrong.

       -h264, -avc
	      Force the program to treat the input as MPEG-4/AVC.

       -h262  Force the program to treat the input as MPEG-2.

SEE ALSO

       The full documentation for esfilter is maintained as a Texinfo manual.  Please check http://tstools.berlios.de for more information.

esfilter 1.11							   November 2008						      ESFILTER:(1)
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