From 947d39462e26b0edee9b58003ea579552dbf4fa8 Mon Sep 17 00:00:00 2001 From: Philippe Waroquiers Date: Sat, 20 Apr 2019 14:14:23 +0200 Subject: Implement | (pipe) command. The pipe command allows to run a GDB command, and pipe its output to a shell command: (gdb) help pipe Send the output of a gdb command to a shell command. Usage: | [COMMAND] | SHELL_COMMAND Usage: | -d DELIM COMMAND DELIM SHELL_COMMAND Usage: pipe [COMMAND] | SHELL_COMMAND Usage: pipe -d DELIM COMMAND DELIM SHELL_COMMAND Executes COMMAND and sends its output to SHELL_COMMAND. The -d option indicates to use the string DELIM to separate COMMAND from SHELL_COMMAND, in alternative to |. This is useful in case COMMAND contains a | character. With no COMMAND, repeat the last executed command and send its output to SHELL_COMMAND. (gdb) For example: (gdb) pipe print some_data_structure | grep -B3 -A3 something The pipe character is defined as an alias for pipe command, so that the above can be typed as: (gdb) | print some_data_structure | grep -B3 -A3 something If no GDB COMMAND is given, then the previous command is relaunched, and its output is sent to the given SHELL_COMMAND. This also defines convenience vars $_shell_exitcode and $_shell_exitsignal to record the exit code and exit signal of the last shell command launched by GDB e.g. by "shell", "pipe", ... gdb/ChangeLog 2019-05-31 Philippe Waroquiers * cli/cli-cmds.c (pipe_command): New function. (_initialize_cli_cmds): Call add_com for pipe_command. Define | as an alias for pipe. (exit_status_set_internal_vars): New function. (shell_escape): Call exit_status_set_internal_vars. cli/cli-decode.c (find_command_name_length): Recognize | as a single character command. --- gdb/cli/cli-cmds.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++ gdb/cli/cli-decode.c | 4 +- 2 files changed, 106 insertions(+), 2 deletions(-) (limited to 'gdb/cli') diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c index daf409a..bb2b04d 100644 --- a/gdb/cli/cli-cmds.c +++ b/gdb/cli/cli-cmds.c @@ -24,6 +24,7 @@ #include "completer.h" #include "target.h" /* For baud_rate, remote_debug and remote_timeout. */ #include "common/gdb_wait.h" /* For shell escape implementation. */ +#include "gdbcmd.h" #include "gdb_regex.h" /* Used by apropos_command. */ #include "gdb_vfork.h" #include "linespec.h" @@ -41,6 +42,7 @@ #include "block.h" #include "ui-out.h" +#include "interps.h" #include "top.h" #include "cli/cli-decode.h" @@ -668,6 +670,25 @@ echo_command (const char *text, int from_tty) gdb_flush (gdb_stdout); } +/* Sets the last launched shell command convenience variables based on + EXIT_STATUS. */ + +static void +exit_status_set_internal_vars (int exit_status) +{ + struct internalvar *var_code = lookup_internalvar ("_shell_exitcode"); + struct internalvar *var_signal = lookup_internalvar ("_shell_exitsignal"); + + clear_internalvar (var_code); + clear_internalvar (var_signal); + if (WIFEXITED (exit_status)) + set_internalvar_integer (var_code, WEXITSTATUS (exit_status)); + else if (WIFSIGNALED (exit_status)) + set_internalvar_integer (var_signal, WTERMSIG (exit_status)); + else + warning (_("unexpected shell command exit status %d\n"), exit_status); +} + static void shell_escape (const char *arg, int from_tty) { @@ -689,6 +710,7 @@ shell_escape (const char *arg, int from_tty) /* Make sure to return to the directory GDB thinks it is, in case the shell command we just ran changed it. */ chdir (current_directory); + exit_status_set_internal_vars (rc); #endif #else /* Can fork. */ int status, pid; @@ -716,6 +738,7 @@ shell_escape (const char *arg, int from_tty) waitpid (pid, &status, 0); else error (_("Fork failed")); + exit_status_set_internal_vars (status); #endif /* Can fork. */ } @@ -827,6 +850,70 @@ edit_command (const char *arg, int from_tty) xfree (p); } +/* Implementation of the "pipe" command. */ + +static void +pipe_command (const char *arg, int from_tty) +{ + std::string delim ("|"); + + if (arg != nullptr && check_for_argument (&arg, "-d", 2)) + { + delim = extract_arg (&arg); + if (delim.empty ()) + error (_("Missing delimiter DELIM after -d")); + } + + const char *command = arg; + if (command == nullptr) + error (_("Missing COMMAND")); + + arg = strstr (arg, delim.c_str ()); + + if (arg == nullptr) + error (_("Missing delimiter before SHELL_COMMAND")); + + std::string gdb_cmd (command, arg - command); + + arg += delim.length (); /* Skip the delimiter. */ + + if (gdb_cmd.empty ()) + { + repeat_previous (); + gdb_cmd = skip_spaces (get_saved_command_line ()); + if (gdb_cmd.empty ()) + error (_("No previous command to relaunch")); + } + + const char *shell_command = skip_spaces (arg); + if (*shell_command == '\0') + error (_("Missing SHELL_COMMAND")); + + FILE *to_shell_command = popen (shell_command, "w"); + + if (to_shell_command == nullptr) + error (_("Error launching \"%s\""), shell_command); + + try + { + stdio_file pipe_file (to_shell_command); + + execute_command_to_ui_file (&pipe_file, gdb_cmd.c_str (), from_tty); + } + catch (...) + { + pclose (to_shell_command); + throw; + } + + int exit_status = pclose (to_shell_command); + + if (exit_status < 0) + error (_("shell command \"%s\" failed: %s"), shell_command, + safe_strerror (errno)); + exit_status_set_internal_vars (exit_status); +} + static void list_command (const char *arg, int from_tty) { @@ -1818,6 +1905,23 @@ Uses EDITOR environment variable contents as editor (or ex as default).")); c->completer = location_completer; + c = add_com ("pipe", class_support, pipe_command, _("\ +Send the output of a gdb command to a shell command.\n\ +Usage: | [COMMAND] | SHELL_COMMAND\n\ +Usage: | -d DELIM COMMAND DELIM SHELL_COMMAND\n\ +Usage: pipe [COMMAND] | SHELL_COMMAND\n\ +Usage: pipe -d DELIM COMMAND DELIM SHELL_COMMAND\n\ +\n\ +Executes COMMAND and sends its output to SHELL_COMMAND.\n\ +\n\ +The -d option indicates to use the string DELIM to separate COMMAND\n\ +from SHELL_COMMAND, in alternative to |. This is useful in\n\ +case COMMAND contains a | character.\n\ +\n\ +With no COMMAND, repeat the last executed command\n\ +and send its output to SHELL_COMMAND.")); + add_com_alias ("|", "pipe", class_support, 0); + add_com ("list", class_files, list_command, _("\ List specified function or line.\n\ With no argument, lists ten more lines after or around previous listing.\n\ diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c index 72e2a97..e3076f2 100644 --- a/gdb/cli/cli-decode.c +++ b/gdb/cli/cli-decode.c @@ -1311,9 +1311,9 @@ find_command_name_length (const char *text) Note that this is larger than the character set allowed when creating user-defined commands. */ - /* Recognize '!' as a single character command so that, e.g., "!ls" + /* Recognize the single character commands so that, e.g., "!ls" works as expected. */ - if (*p == '!') + if (*p == '!' || *p == '|') return 1; while (isalnum (*p) || *p == '-' || *p == '_' -- cgit v1.1