To start GT.M from a POSIX shell:

To start GT.M in UTF-8 mode from a POSIX shell:

To start GT.M from a C-type shell:

To start GT.M in UTF-8 mode from a C-type shell:

To start GT.M without using any script:

To start GT.M in UTF-8 mode without using any script:


If you are configuring a GT.M environment without using the gtmprofile script (or the gtm script which sources gtmprofile), bear in mind the following recommendation from FIS:

  • All GT.M processes should use the same settings for gtm_log and gtm_tmp, especially for production environments. This is because gtmsecshr inherits these values from whichever GT.M process first uses its services.

  • If there are multiple GT.M versions active on a system, FIS recommends different sets of gtm_log and gtm_tmp values for each version as using the same values for different distributions can cause significant performance issues.

GT.M has three invocation modes: compiler, direct, and auto-start. To invoke GT.M in these modes, provide the following arguments to the gtm script or the mumps command.

When executing M programs, GT.M incrementally links any called programs. For example, the command GTM> do ^TEST links the object file TEST.o and executes it; if the TESTM program calls other M routines, those are automatically compiled and linked.


When possible, GT.M verifies that MUMPS, MUPIP, DSE and LKE reside in $gtm_dist. If the path to the executable and the path to $gtm_dist do not match each executable issues an error. In cases where the executable path could not be determined, each executable defers issuing an error until it is required.

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