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Diffstat (limited to 'signal.c')
| -rw-r--r-- | signal.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/signal.c b/signal.c new file mode 100644 index 0000000..4256ca4 --- /dev/null +++ b/signal.c @@ -0,0 +1,265 @@ +/* signal.c: signal and miscellaneous routines for the ed line editor. */ +/* GNU ed - The GNU line editor. + Copyright (C) 1993, 1994 Andrew Moore, Talke Studio + Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 + Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include <ctype.h> +#include <errno.h> +#include <limits.h> +#include <setjmp.h> +#include <signal.h> +#include <stdlib.h> +#include <string.h> +#include <termios.h> +#include <unistd.h> +#include <sys/ioctl.h> + +#include "ed.h" + + +jmp_buf jmp_state; +static int mutex = 0; /* If > 0, signals stay pending */ +static int window_lines_ = 22; /* scroll length: ws_row - 2 */ +static int window_columns_ = 72; +static bool sighup_pending = false; +static bool sigint_pending = false; + + +static void sighup_handler( int signum ) + { + signum = 0; /* keep compiler happy */ + if( mutex ) sighup_pending = true; + else + { + const char hb[] = "ed.hup"; + sighup_pending = false; + if( last_addr() && modified() && + write_file( hb, "w", 1, last_addr() ) < 0 ) + { + char * const s = getenv( "HOME" ); + const int len = ( s ? strlen( s ) : 0 ); + const int need_slash = ( ( !len || s[len-1] != '/' ) ? 1 : 0 ); + char * const hup = ( ( len + need_slash + (int)sizeof hb < path_max( 0 ) ) ? + (char *) malloc( len + need_slash + sizeof hb ) : 0 ); + if( len && hup ) /* hup filename */ + { + memcpy( hup, s, len ); + if( need_slash ) hup[len] = '/'; + memcpy( hup + len + need_slash, hb, sizeof hb ); + if( write_file( hup, "w", 1, last_addr() ) >= 0 ) exit( 0 ); + } + exit( 1 ); /* hup file write failed */ + } + exit( 0 ); + } + } + + +static void sigint_handler( int signum ) + { + if( mutex ) sigint_pending = true; + else + { + sigset_t set; + sigint_pending = false; + sigemptyset( &set ); + sigaddset( &set, signum ); + sigprocmask( SIG_UNBLOCK, &set, 0 ); + longjmp( jmp_state, -1 ); + } + } + + +static void sigwinch_handler( int signum ) + { +#ifdef TIOCGWINSZ + struct winsize ws; /* window size structure */ + + if( ioctl( 0, TIOCGWINSZ, (char *) &ws ) >= 0 ) + { + /* Sanity check values of environment vars */ + if( ws.ws_row > 2 && ws.ws_row < 600 ) window_lines_ = ws.ws_row - 2; + if( ws.ws_col > 8 && ws.ws_col < 1800 ) window_columns_ = ws.ws_col - 8; + } +#endif + signum = 0; /* keep compiler happy */ + } + + +static int set_signal( int signum, void (*handler)( int ) ) + { + struct sigaction new_action; + + new_action.sa_handler = handler; + sigemptyset( &new_action.sa_mask ); +#ifdef SA_RESTART + new_action.sa_flags = SA_RESTART; +#else + new_action.sa_flags = 0; +#endif + return sigaction( signum, &new_action, 0 ); + } + + +void enable_interrupts( void ) + { + if( --mutex <= 0 ) + { + mutex = 0; + if( sighup_pending ) sighup_handler( SIGHUP ); + if( sigint_pending ) sigint_handler( SIGINT ); + } + } + + +void disable_interrupts( void ) { ++mutex; } + + +void set_signals( void ) + { +#ifdef SIGWINCH + sigwinch_handler( SIGWINCH ); + if( isatty( 0 ) ) set_signal( SIGWINCH, sigwinch_handler ); +#endif + set_signal( SIGHUP, sighup_handler ); + set_signal( SIGQUIT, SIG_IGN ); + set_signal( SIGINT, sigint_handler ); + } + + +void set_window_lines( const int lines ) { window_lines_ = lines; } +int window_columns( void ) { return window_columns_; } +int window_lines( void ) { return window_lines_; } + + +/* convert a string to int with out_of_range detection */ +bool parse_int( int * const i, const char * const str, const char ** const tail ) + { + char * tmp; + long li; + + errno = 0; + *i = li = strtol( str, &tmp, 10 ); + if( tail ) *tail = tmp; + if( tmp == str ) + { + set_error_msg( "Bad numerical result" ); + *i = 0; + return false; + } + if( errno == ERANGE || li > INT_MAX || li < INT_MIN ) + { + set_error_msg( "Numerical result out of range" ); + *i = 0; + return false; + } + return true; + } + + +/* assure at least a minimum size for buffer `buf' */ +bool resize_buffer( char ** const buf, int * const size, const int min_size ) + { + if( *size < min_size ) + { + const int new_size = ( min_size < 512 ? 512 : ( min_size / 512 ) * 1024 ); + void * new_buf = 0; + disable_interrupts(); + if( *buf ) new_buf = realloc( *buf, new_size ); + else new_buf = malloc( new_size ); + if( !new_buf ) + { + show_strerror( 0, errno ); + set_error_msg( "Memory exhausted" ); + enable_interrupts(); + return false; + } + *size = new_size; + *buf = (char *)new_buf; + enable_interrupts(); + } + return true; + } + + +/* assure at least a minimum size for buffer `buf' */ +bool resize_line_buffer( const line_t *** const buf, int * const size, + const int min_size ) + { + if( *size < min_size ) + { + const int new_size = ( min_size < 512 ? 512 : ( min_size / 512 ) * 1024 ); + void * new_buf = 0; + disable_interrupts(); + if( *buf ) new_buf = realloc( *buf, new_size ); + else new_buf = malloc( new_size ); + if( !new_buf ) + { + show_strerror( 0, errno ); + set_error_msg( "Memory exhausted" ); + enable_interrupts(); + return false; + } + *size = new_size; + *buf = (const line_t **)new_buf; + enable_interrupts(); + } + return true; + } + + +/* assure at least a minimum size for buffer `buf' */ +bool resize_undo_buffer( undo_t ** const buf, int * const size, + const int min_size ) + { + if( *size < min_size ) + { + const int new_size = ( min_size < 512 ? 512 : ( min_size / 512 ) * 1024 ); + void * new_buf = 0; + disable_interrupts(); + if( *buf ) new_buf = realloc( *buf, new_size ); + else new_buf = malloc( new_size ); + if( !new_buf ) + { + show_strerror( 0, errno ); + set_error_msg( "Memory exhausted" ); + enable_interrupts(); + return false; + } + *size = new_size; + *buf = (undo_t *)new_buf; + enable_interrupts(); + } + return true; + } + + +/* return unescaped copy of escaped string */ +const char * strip_escapes( const char * p ) + { + static char * buf = 0; + static int bufsz = 0; + const int len = strlen( p ); + int i = 0; + + if( !resize_buffer( &buf, &bufsz, len + 1 ) ) return 0; + /* assert: no trailing escape */ + while( ( buf[i++] = ( (*p == '\\' ) ? *++p : *p ) ) ) + ++p; + return buf; + } |