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=== SvarCOM implementation notes ===
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=== SWAPPING =================================================================
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While conventional RAM is scarce, a command line interpreter must make effort
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to reduce its memory footprint when launching applications. SvarCOM does that
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by installing a small executable module in memory, called RMOD (for Resident
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MODule). SvarCOM pre-sets RMOD so knows how to execute the external program
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and removes itself from memory, letting RMOD do the job. RMOD executes the
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application, waits for it to finish and then calls back SvarCOM.
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=== NLS strings ==============================================================
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SvarCOM can output information in many languages. To do so, it relies on a
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precompiled resource file named SVARCOM.LNG. When SvarCOM starts, it looks
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for this file in the %NLSPATH% directory and loads from it the part that
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contains the %LANG% language. All this is done by nls_langreload().
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The SVARCOM.LNG file is compiled by a separate tool: TLUMACZ. It takes
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CATS-style language files as input and compiles them into a single SVARCOM.LNG
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resource file. It also produces a DEFAULT.LNG with english strings only, this
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one is embedded into the SvarCOM executable to display english text in case
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SVARCOM.LNG is unavailable.
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mateuszvis |
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=== Batch files support ======================================================
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When SvarCOM executes a command, it checks first if it has a *.BAT extension.
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If so, it switches into 'batch-processing' mode:
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- Writes the batch filename into its persistent (rmod-owned) buffer, along
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with a line counter that holds the number of "next line to be executed".
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- When a batch file CALLs another batch file, then a new SvarCOM instance is
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started. This ensures that once the CALLed batch ends, processing will
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return to the original batch file at the correct position.
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When the batch buffer is non-zero, SvarCOM does not ask the user for a
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command. Instead, it opens the batch file, jumps to the "next line to be
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executed" and loads the command from there, incrementing this counter in the
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process. The maximum length of a batch file is of 65535 lines (any lines after
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this limit will be ignored).
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====================================================================== EOF ===
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