Se você quiser apenas os títulos das seções, grep
para eles. Eles estão no ALLCAPS e são as únicas linhas que não têm espaços à esquerda:
$ man bash | grep '^[A-Z]'
BASH(1) General Commands Manual BASH(1)
NAME
SYNOPSIS
COPYRIGHT
DESCRIPTION
OPTIONS
ARGUMENTS
INVOCATION
DEFINITIONS
RESERVED WORDS
SHELL GRAMMAR
COMMENTS
QUOTING
PARAMETERS
EXPANSION
REDIRECTION
ALIASES
FUNCTIONS
ARITHMETIC EVALUATION
CONDITIONAL EXPRESSIONS
SIMPLE COMMAND EXPANSION
COMMAND EXECUTION
COMMAND EXECUTION ENVIRONMENT
ENVIRONMENT
EXIT STATUS
SIGNALS
JOB CONTROL
PROMPTING
READLINE
HISTORY
HISTORY EXPANSION
SHELL BUILTIN COMMANDS
RESTRICTED SHELL
SEE ALSO
FILES
AUTHORS
BUG REPORTS
BUGS
GNU Bash 4.3 2014 February 2 BASH(1)