| ### 3.1.6 Command line options The startup syntax is
    Singular  [options] [file1 [file2 ...]]
    ESingular  [options] [file1 [file2 ...]]
Options can be given in both their long and short format. The following options control the general behaviour of SINGULAR: `-d`, `--sdb` Enable the use of the source code debugger. See Source code debugger. `-e`, `--echo[=VAL]` Set value of variable `echo` to `VAL` (integer in the range 0, ..., 9). Without an argument, `echo` is set to 1, which echoes all input coming from a file. By default, the value of `echo` is 0. See echo. `-h`, `--help` Print a one-line description of each command line option and exit. `--allow-net` Allow the help browsers based on a web browser to fetch HTML manual pages over the net from the WWW home-site of SINGULAR. See The online help system, for more info. `--browser="VAL"` Use `VAL` as browser for the SINGULAR online manual. `VAL` may be one of the browsers mentioned in `LIB/help.cnf`, for example `html` (Windows only), `mozilla`, `firefox`, `konqueror`, `galeon`, `netscape`, `safari` (OsX only), `xinfo`, `tkinfo`, `info`, `builtin`, or `emacs`. Depending on your platform and local installation, only some browsers might be available. The default browser is `html` for Windows and one based on a web browser for Unix platforms. See The online help system, for more info. `--no-rc` Do not execute the `.singularrc` file on start-up. By default, this file is executed on start-up. See Startup sequence. `--no-stdlib` Do not load the library `standard.lib` on start-up. By default, this library is loaded on start-up. See Startup sequence. `--no-warn` Do not display warning messages. `--no-out` Suppress display of all output. `--no-shell` Runs Singular in restricted mode to disallow shell escape commands. Objects of type link will also be unable to use. `-t`, `--no-tty` Do not redefine the characteristics of the terminal. This option should be used for batch processes. `-q`, `--quiet` Do not print the start-up banner and messages when loading libraries. Furthermore, redirect `stderr` (all error messages) to `stdout` (normal output channel). This option should be used if SINGULAR's output is redirected to a file. `-v` Print extended information about the version and configuration of SINGULAR (used optional parts, compilation date, start of random generator etc.). This information should be included if a user reports an error to the authors. It also list all the used directories/files (see Used environment variables). The following command line options allow manipulations of the timer and the pseudo random generator and enable the passing of commands and strings to SINGULAR: `-c`, `--execute=STRING` Execute `STRING` as (a sequence of) SINGULAR commands on start-up after the `.singularrc` file is executed, but prior to executing the files given on the command line. E.g., `Singular -c "help all.lib; quit;"` shows the help for the library `all.lib` and exits. `-u`, `--user-option=STRING` Returns `STRING` on `system("--user-option")`. This is useful for passing arbitrary arguments from the command line to the SINGULAR interpreter. E.g., `Singular -u "xxx.dump" -c 'getdump(system("--user-option"))'` reads the file `xxx.dump` at start-up and allows the user to start working with all the objects defined in a previous session. `-r`, `--random=SEED` Seed (i.e., set the initial value of) the pseudo random generator with integer `SEED`. If this option is not given, then the random generator is seeded with a time-based `SEED` (the number of seconds since January, 1, 1970, on Unix-like operating systems, to be precise). `--min-time=SECS` If the `timer` (see timer), resp. `rtimer` (see rtimer) , variable is set, report only times larger than `SECS` seconds (`SECS` needs to be a floating point number greater than 0). By default, this value is set to 0.5 (i.e., half a second). E.g., the option `--min-time=0.01` forces SINGULAR to report all times larger than 1/100 of a second. `--ticks-per-sec=TICKS` Set unit of timer to `TICKS` ticks per second (i.e., the value reported by the `timer` and `rtimer` variable divided by `TICKS` gives the time in seconds). By default, this value is 1. `--cpus=CPUs` set the maximal number of CPUs to use. `--cntrlc=C` set the default answer for interrupt signals to C which should be a for abort, c for continue or q for quit. The next three options are of interest for the use with ssi links: `-b`, `--batch` Run in batch mode. Opens a TCP/IP connection with host specified by `--MPhost` at the port specified by `--MPport`. Input is read from and output is written to this connection in the format given by `--link`. See Ssi links. `--MPport=PORT` Use `PORT` as default port number for connections (whenever not further specified). This option is mandatory when the `--batch` option is given. See Ssi links. `--MPhost=HOST` Use `HOST` as default host for connections (whenever not further specified). This option is mandatory when the `--batch` option is given. See Ssi links. Finally, the following options are only available when running `ESingular` (see Running SINGULAR under Emacs for details). `--emacs=EMACS` Use `EMACS` as Emacs program to run the SINGULAR Emacs interface, where `EMACS` may e.g. be emacs or xemacs. `--emacs-dir=DIR` Set the singular-emacs-home-directory, which is the directory where singular.el can be found, to `DIR`. `--emacs-load=FILE` Load `FILE` on Emacs start-up, instead of the default load file. `--singular=PROG` Start `PROG` as SINGULAR program within Emacs The value of options given to SINGULAR (resp. their default values, if an option was not given), can be checked with the command `system("--`long_option_name`")`. See system.
      system("--quiet");    // if ``quiet'' 1, otherwise 0
    ==> 1
      system("--min-time"); // minimal reported time
    ==> 0.5
      system("--random");   // seed of the random generator
    ==> 12345678
Furthermore, the value of options (e.g., `--browser`) can be re-defined while SINGULAR is running using the command `system("--`long_option_name_string `",`expression`)`. See system.
      system("--browser", "builtin");  // sets browser to 'builtin'
      system("--ticks-per-sec", 100);  // sets timer resolution to 100

User manual for Singular version 4.4.0, 2024, generated by texi2html.