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Diffstat (limited to 'doc_src/isatty.txt')
| -rw-r--r-- | doc_src/isatty.txt | 35 |
1 files changed, 28 insertions, 7 deletions
diff --git a/doc_src/isatty.txt b/doc_src/isatty.txt index d3b52892..f6ab500e 100644 --- a/doc_src/isatty.txt +++ b/doc_src/isatty.txt @@ -1,14 +1,35 @@ -\section isatty isatty - test if the specified file descriptor is a tty +\section isatty isatty - test if a file descriptor is a tty. \subsection isatty-synopsis Synopsis - <tt>isatty [FILE DESCRIPTOR]</tt> +\fish{synopsis} +isatty [FILE DESCRIPTOR] +\endfish \subsection isatty-description Description -<tt>isatty</tt> tests if a file descriptor is a tty. -<tt>FILE DESCRIPTOR</tt> may be either the number of a file descriptor, or one of the -strings <tt>stdin</tt>, \c stdout and <tt>stderr</tt>. +`isatty` tests if a file descriptor is a tty. -If the specified file descriptor is a tty, the exit status of the command is -zero. Otherwise, it is non-zero. +`FILE DESCRIPTOR` may be either the number of a file descriptor, or one of the strings `stdin`, `stdout`, or `stderr`. +If the specified file descriptor is a tty, the exit status of the command is zero. Otherwise, the exit status is non-zero. No messages are printed to standard error. + + +\subsection isatty-examples Examples + +From an interactive shell, the commands below exit with a return value of zero: + +\fish +isatty +isatty stdout +isatty 2 +echo | isatty 1 +\endfish + +And these will exit non-zero: + +\fish +echo | isatty +isatty 9 +isatty stdout > file +isatty 2 2> file +\endfish |