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Pamvalidate User Manual(1)  General Commands Manual Pamvalidate User Manual(1)

NAME
       pamvalidate - validate Netpbm image format

SYNOPSIS
       pamvalidate

DESCRIPTION
       This program is part of Netpbm(1).

       pamvalidate  copies a Netpbm image from Standard Input to Standard Out-
       put, except that if there are certain violations of the image format in
       the input, pamvalidate fails without producing any output.

       This  is  most  useful  in a pipeline, before a stage you don't want to
       start working on Netpbm input until it knows it can  get  all  the  way
       through  it.   For example, assume you are converting PPM images to PNG
       and you don't want to produce a partial  PNG  file  under  any  circum-
       stance.  If you just use pnmtopng, and the PPM input is truncated half-
       way through the raster, pnmtopng fails, but also produces about half of
       a  PNG  file.  To prevent that, pass your PPM input through pamvalidate
       on its way to pnmtopng.  Then, pamvalidate will fail, and  consequently
       the  pipeline  will fail, before pnmtopng has seen any input and there-
       fore before pnmtopng has produced any output.

       These are the kinds of format violations pamvalidate detects:

       •      A purported sample value exceeds the declared maxval.

       •      The stream ends prematurely.

       This program works on multi-image streams,  producing  a  corresponding
       output stream.

       See pamfix for a way to salvage an invalid Netpbm image stream.

OPTIONS
       There are no command line options defined specifically for pamvalidate,
       but it recognizes the options common to all programs based on libnetpbm
       (See
        Common Options ⟨index.html#commonoptions⟩ .)

SEE ALSO
       pam(1) pnm(1) pamfix(1)

HISTORY
       pamvalidate was new in Netpbm 10.66 (March 2014).

DOCUMENT SOURCE
       This  manual  page was generated by the Netpbm tool 'makeman' from HTML
       source.  The master documentation is at

              http://netpbm.sourceforge.net/doc/pamvalidate.html

netpbm documentation             22 March 2014      Pamvalidate User Manual(1)

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