/* Command processing for GNU Make. Copyright (C) 1988-2016 Free Software Foundation, Inc. This file is part of GNU Make. GNU Make 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. GNU Make 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 . */ #include "makeint.h" #include "filedef.h" #include "dep.h" #include "variable.h" #include "job.h" #include "commands.h" #ifdef WINDOWS32 #include #include "w32err.h" # ifdef CONFIG_NEW_WIN_CHILDREN # include "w32/winchildren.h" # endif #endif #ifdef CONFIG_WITH_LAZY_DEPS_VARS # include #endif #if VMS # define FILE_LIST_SEPARATOR (vms_comma_separator ? ',' : ' ') #else # define FILE_LIST_SEPARATOR ' ' #endif #ifndef HAVE_UNISTD_H int getpid (); #endif #ifndef CONFIG_WITH_STRCACHE2 static unsigned long dep_hash_1 (const void *key) { const struct dep *d = key; return_STRING_HASH_1 (dep_name (d)); } static unsigned long dep_hash_2 (const void *key) { const struct dep *d = key; return_STRING_HASH_2 (dep_name (d)); } static int dep_hash_cmp (const void *x, const void *y) { const struct dep *dx = x; const struct dep *dy = y; return strcmp (dep_name (dx), dep_name (dy)); } #else /* CONFIG_WITH_STRCACHE2 */ /* Exploit the fact that all names are in the string cache. This means equal names shall have the same storage and there is no need for hashing or comparing. Use the address as the first hash, avoiding any touching of the name, and the length as the second. */ static unsigned long dep_hash_1 (const void *key) { const char *name = dep_name ((struct dep const *) key); assert (strcache2_is_cached (&file_strcache, name)); return (size_t) name / sizeof(void *); } static unsigned long dep_hash_2 (const void *key) { const char *name = dep_name ((struct dep const *) key); return strcache2_get_len (&file_strcache, name); } static int dep_hash_cmp (const void *x, const void *y) { struct dep *dx = (struct dep *) x; struct dep *dy = (struct dep *) y; const char *dxname = dep_name (dx); const char *dyname = dep_name (dy); int cmp = dxname == dyname ? 0 : 1; /* check preconds: both cached and the cache contains no duplicates. */ assert (strcache2_is_cached (&file_strcache, dxname)); assert (strcache2_is_cached (&file_strcache, dyname)); assert (cmp == 0 || strcmp (dxname, dyname) != 0); /* If the names are the same but ignore_mtimes are not equal, one of these is an order-only prerequisite and one isn't. That means that we should remove the one that isn't and keep the one that is. */ if (!cmp && dx->ignore_mtime != dy->ignore_mtime) dx->ignore_mtime = dy->ignore_mtime = 0; return cmp; } #endif /* CONFIG_WITH_STRCACHE2 */ #ifdef CONFIG_WITH_LAZY_DEPS_VARS /* Create as copy of DEPS without duplicates, similar to what set_file_variables does. Used by func_deps. */ struct dep *create_uniqute_deps_chain (struct dep *deps) { struct dep *d; struct dep *head = NULL; struct dep **ppnext= &head; struct hash_table dep_hash; void **slot; hash_init (&dep_hash, 500, dep_hash_1, dep_hash_2, dep_hash_cmp); for (d = deps; d != 0; d = d->next) { if (d->need_2nd_expansion) continue; slot = hash_find_slot (&dep_hash, d); if (HASH_VACANT (*slot)) { struct dep *n = alloc_dep(); *n = *d; n->next = NULL; *ppnext = n; ppnext = &n->next; hash_insert_at (&dep_hash, n, slot); } else { /* Upgrade order only if a normal dep exists. Note! Elected not to upgrade the original, only the sanitized list, need to check that out later. FIXME TODO */ struct dep *d2 = (struct dep *)*slot; if (d->ignore_mtime != d2->ignore_mtime) d->ignore_mtime = d2->ignore_mtime = 0; } } return head; } #endif /* CONFIG_WITH_LAZY_DEPS_VARS */ /* Set FILE's automatic variables up. */ void #if defined(CONFIG_WITH_COMMANDS_FUNC) || defined (CONFIG_WITH_DOT_MUST_MAKE) set_file_variables (struct file *file, int called_early) #else set_file_variables (struct file *file) #endif { struct dep *d; const char *at, *percent, *star, *less; #ifdef CONFIG_WITH_STRCACHE2 const char *org_stem = file->stem; #endif #ifndef NO_ARCHIVES /* If the target is an archive member 'lib(member)', then $@ is 'lib' and $% is 'member'. */ if (ar_name (file->name)) { unsigned int len; const char *cp; char *p; cp = strchr (file->name, '('); p = alloca (cp - file->name + 1); memcpy (p, file->name, cp - file->name); p[cp - file->name] = '\0'; at = p; len = strlen (cp + 1); p = alloca (len); memcpy (p, cp + 1, len - 1); p[len - 1] = '\0'; percent = p; } else #endif /* NO_ARCHIVES. */ { at = file->name; percent = ""; } /* $* is the stem from an implicit or static pattern rule. */ if (file->stem == 0) { /* In Unix make, $* is set to the target name with any suffix in the .SUFFIXES list stripped off for explicit rules. We store this in the 'stem' member. */ const char *name; unsigned int len; #ifndef NO_ARCHIVES if (ar_name (file->name)) { name = strchr (file->name, '(') + 1; len = strlen (name) - 1; } else #endif { name = file->name; #ifndef CONFIG_WITH_STRCACHE2 len = strlen (name); #else len = strcache2_get_len (&file_strcache, name); #endif } #ifndef CONFIG_WITH_STRCACHE2 for (d = enter_file (strcache_add (".SUFFIXES"))->deps; d ; d = d->next) { unsigned int slen = strlen (dep_name (d)); #else for (d = enter_file (suffixes_strcached)->deps; d ; d = d->next) { unsigned int slen = strcache2_get_len (&file_strcache, dep_name (d)); #endif if (len > slen && strneq (dep_name (d), name + (len - slen), slen)) { file->stem = strcache_add_len (name, len - slen); break; } } if (d == 0) file->stem = ""; } star = file->stem; /* $< is the first not order-only dependency. */ less = ""; for (d = file->deps; d != 0; d = d->next) if (!d->ignore_mtime) { if (!d->need_2nd_expansion) less = dep_name (d); break; } if (file->cmds == default_file->cmds) /* This file got its commands from .DEFAULT. In this case $< is the same as $@. */ less = at; #define DEFINE_VARIABLE(name, len, value) \ (void) define_variable_for_file (name,len,value,o_automatic,0,file) /* Define the variables. */ #ifndef CONFIG_WITH_RDONLY_VARIABLE_VALUE DEFINE_VARIABLE ("<", 1, less); DEFINE_VARIABLE ("*", 1, star); DEFINE_VARIABLE ("@", 1, at); DEFINE_VARIABLE ("%", 1, percent); #else /* CONFIG_WITH_RDONLY_VARIABLE_VALUE */ # define DEFINE_VARIABLE_RO_VAL(name, len, value, value_len) \ define_variable_in_set((name), (len), (value), (value_len), -1, \ (o_automatic), 0, (file)->variables->set, NILF) if (*less == '\0') DEFINE_VARIABLE_RO_VAL ("<", 1, "", 0); else if (less != at || at == file->name) DEFINE_VARIABLE_RO_VAL ("<", 1, less, strcache_get_len (less)); else DEFINE_VARIABLE ("<", 1, less); if (*star == '\0') DEFINE_VARIABLE_RO_VAL ("*", 1, "", 0); else if (file->stem != org_stem) DEFINE_VARIABLE_RO_VAL ("*", 1, star, strcache_get_len (star)); else DEFINE_VARIABLE ("*", 1, star); if (at == file->name) DEFINE_VARIABLE_RO_VAL ("@", 1, at, strcache_get_len (at)); else DEFINE_VARIABLE ("@", 1, at); if (*percent == '\0') DEFINE_VARIABLE_RO_VAL ("%", 1, "", 0); else DEFINE_VARIABLE ("%", 1, percent); #endif /* CONFIG_WITH_RDONLY_VARIABLE_VALUE */ #if defined(CONFIG_WITH_COMMANDS_FUNC) || defined (CONFIG_WITH_DOT_MUST_MAKE) /* The $^, $+, $? and $| variables should not be set if we're called early by a .MUST_MAKE invocation or $(commands ). */ if (called_early) return; #endif /* Compute the values for $^, $+, $?, and $|. */ #ifdef CONFIG_WITH_LAZY_DEPS_VARS /* Lazy doesn't work for double colon rules with multiple files with commands, nor for files that has been thru rehash_file() (vpath). */ if ( ( file->double_colon && ( file->double_colon != file || file->last != file)) || file->name != file->hname) /* XXX: Rehashed files should be fixable! */ #endif { static char *plus_value=0, *bar_value=0, *qmark_value=0; static unsigned int plus_max=0, bar_max=0, qmark_max=0; unsigned int qmark_len, plus_len, bar_len; char *cp; char *caret_value; char *qp; char *bp; unsigned int len; struct hash_table dep_hash; void **slot; /* Compute first the value for $+, which is supposed to contain duplicate dependencies as they were listed in the makefile. */ plus_len = 0; bar_len = 0; for (d = file->deps; d != 0; d = d->next) { if (!d->need_2nd_expansion) { if (d->ignore_mtime) #ifndef CONFIG_WITH_STRCACHE2 bar_len += strlen (dep_name (d)) + 1; #else bar_len += strcache2_get_len (&file_strcache, dep_name (d)) + 1; #endif else #ifndef CONFIG_WITH_STRCACHE2 plus_len += strlen (dep_name (d)) + 1; #else plus_len += strcache2_get_len (&file_strcache, dep_name (d)) + 1; #endif } } if (bar_len == 0) bar_len++; if (plus_len == 0) plus_len++; if (plus_len > plus_max) plus_value = xrealloc (plus_value, plus_max = plus_len); cp = plus_value; qmark_len = plus_len + 1; /* Will be this or less. */ for (d = file->deps; d != 0; d = d->next) if (! d->ignore_mtime && ! d->need_2nd_expansion) { const char *c = dep_name (d); #ifndef NO_ARCHIVES if (ar_name (c)) { c = strchr (c, '(') + 1; len = strlen (c) - 1; } else #endif #ifndef CONFIG_WITH_STRCACHE2 len = strlen (c); #else len = strcache2_get_len (&file_strcache, c); #endif memcpy (cp, c, len); cp += len; *cp++ = FILE_LIST_SEPARATOR; if (! (d->changed || always_make_flag)) qmark_len -= len + 1; /* Don't space in $? for this one. */ } /* Kill the last space and define the variable. */ cp[cp > plus_value ? -1 : 0] = '\0'; DEFINE_VARIABLE ("+", 1, plus_value); /* Compute the values for $^, $?, and $|. */ cp = caret_value = plus_value; /* Reuse the buffer; it's big enough. */ if (qmark_len > qmark_max) qmark_value = xrealloc (qmark_value, qmark_max = qmark_len); qp = qmark_value; if (bar_len > bar_max) bar_value = xrealloc (bar_value, bar_max = bar_len); bp = bar_value; /* Make sure that no dependencies are repeated in $^, $?, and $|. It would be natural to combine the next two loops but we can't do it because of a situation where we have two dep entries, the first is order-only and the second is normal (see below). */ hash_init (&dep_hash, 500, dep_hash_1, dep_hash_2, dep_hash_cmp); for (d = file->deps; d != 0; d = d->next) { if (d->need_2nd_expansion) continue; slot = hash_find_slot (&dep_hash, d); if (HASH_VACANT (*slot)) hash_insert_at (&dep_hash, d, slot); else { /* Check if the two prerequisites have different ignore_mtime. If so then we need to "upgrade" one that is order-only. */ struct dep* hd = (struct dep*) *slot; if (d->ignore_mtime != hd->ignore_mtime) d->ignore_mtime = hd->ignore_mtime = 0; } } for (d = file->deps; d != 0; d = d->next) { const char *c; if (d->need_2nd_expansion || hash_find_item (&dep_hash, d) != d) continue; c = dep_name (d); #ifndef NO_ARCHIVES if (ar_name (c)) { c = strchr (c, '(') + 1; len = strlen (c) - 1; } else #endif #ifndef CONFIG_WITH_STRCACHE2 len = strlen (c); #else len = strcache2_get_len (&file_strcache, c); #endif if (d->ignore_mtime) { memcpy (bp, c, len); bp += len; *bp++ = FILE_LIST_SEPARATOR; } else { memcpy (cp, c, len); cp += len; *cp++ = FILE_LIST_SEPARATOR; if (d->changed || always_make_flag) { memcpy (qp, c, len); qp += len; *qp++ = FILE_LIST_SEPARATOR; } } } hash_free (&dep_hash, 0); /* Kill the last spaces and define the variables. */ cp[cp > caret_value ? -1 : 0] = '\0'; DEFINE_VARIABLE ("^", 1, caret_value); qp[qp > qmark_value ? -1 : 0] = '\0'; DEFINE_VARIABLE ("?", 1, qmark_value); bp[bp > bar_value ? -1 : 0] = '\0'; DEFINE_VARIABLE ("|", 1, bar_value); } #undef DEFINE_VARIABLE } /* Chop CMDS up into individual command lines if necessary. Also set the 'lines_flags' and 'any_recurse' members. */ void chop_commands (struct commands *cmds) { unsigned int nlines, idx; char **lines; /* If we don't have any commands, or we already parsed them, never mind. */ if (!cmds || cmds->command_lines != 0) return; /* Chop CMDS->commands up into lines in CMDS->command_lines. */ if (one_shell) { int l = strlen (cmds->commands); nlines = 1; lines = xmalloc (nlines * sizeof (char *)); lines[0] = xstrdup (cmds->commands); /* Strip the trailing newline. */ if (l > 0 && lines[0][l-1] == '\n') lines[0][l-1] = '\0'; } else { const char *p; nlines = 5; lines = xmalloc (nlines * sizeof (char *)); idx = 0; p = cmds->commands; while (*p != '\0') { const char *end = p; find_end:; end = strchr (end, '\n'); if (end == 0) end = p + strlen (p); else if (end > p && end[-1] == '\\') { int backslash = 1; const char *b; for (b = end - 2; b >= p && *b == '\\'; --b) backslash = !backslash; if (backslash) { ++end; goto find_end; } } if (idx == nlines) { nlines += 2; lines = xrealloc (lines, nlines * sizeof (char *)); } lines[idx++] = xstrndup (p, end - p); p = end; if (*p != '\0') ++p; } if (idx != nlines) { nlines = idx; lines = xrealloc (lines, nlines * sizeof (char *)); } } /* Finally, set the corresponding CMDS->lines_flags elements and the CMDS->any_recurse flag. */ if (nlines > USHRT_MAX) ON (fatal, &cmds->fileinfo, _("Recipe has too many lines (%ud)"), nlines); cmds->ncommand_lines = nlines; cmds->command_lines = lines; cmds->any_recurse = 0; #ifndef CONFIG_WITH_COMMANDS_FUNC cmds->lines_flags = xmalloc (nlines); #else cmds->lines_flags = xmalloc (nlines * sizeof (cmds->lines_flags[0])); #endif for (idx = 0; idx < nlines; ++idx) { unsigned char flags = 0; const char *p = lines[idx]; while (ISBLANK (*p) || *p == '-' || *p == '@' || *p == '+' IF_WITH_COMMANDS_FUNC(|| *p == '%')) switch (*(p++)) { case '+': flags |= COMMANDS_RECURSE; break; case '@': flags |= COMMANDS_SILENT; break; case '-': flags |= COMMANDS_NOERROR; break; #ifdef CONFIG_WITH_COMMANDS_FUNC case '%': flags |= COMMAND_GETTER_SKIP_IT; break; #endif } /* If no explicit '+' was given, look for MAKE variable references. */ if (!(flags & COMMANDS_RECURSE) #ifndef KMK && (strstr (p, "$(MAKE)") != 0 || strstr (p, "${MAKE}") != 0)) #else && (strstr (p, "$(KMK)") != 0 || strstr (p, "${KMK}") != 0 || strstr (p, "$(MAKE)") != 0 || strstr (p, "${MAKE}") != 0)) #endif flags |= COMMANDS_RECURSE; #ifdef CONFIG_WITH_KMK_BUILTIN /* check if kmk builtin command */ if (!strncmp(p, "kmk_builtin_", sizeof("kmk_builtin_") - 1)) flags |= COMMANDS_KMK_BUILTIN; #endif cmds->lines_flags[idx] = flags; cmds->any_recurse |= flags & COMMANDS_RECURSE ? 1 : 0; } } #ifdef CONFIG_WITH_MEMORY_OPTIMIZATIONS /* This is for saving memory in func_commands. */ void free_chopped_commands (struct commands *cmds) { if ( cmds && cmds->command_lines != 0 && cmds->refs == 0) { unsigned idx = cmds->ncommand_lines; while (idx-- > 0) free (cmds->command_lines[idx]); free (cmds->command_lines); free (cmds->lines_flags); cmds->command_lines = 0; cmds->lines_flags = 0; cmds->ncommand_lines = 0; } } #endif /* CONFIG_WITH_MEMORY_OPTIMIZATIONS */ /* Execute the commands to remake FILE. If they are currently executing, return or have already finished executing, just return. Otherwise, fork off a child process to run the first command line in the sequence. */ void execute_file_commands (struct file *file) { const char *p; /* Don't go through all the preparations if the commands are nothing but whitespace. */ for (p = file->cmds->commands; *p != '\0'; ++p) if (!ISSPACE (*p) && *p != '-' && *p != '@' && *p != '+') break; if (*p == '\0') { /* If there are no commands, assume everything worked. */ #ifdef CONFIG_WITH_EXTENDED_NOTPARALLEL file->command_flags |= COMMANDS_NO_COMMANDS; #endif set_command_state (file, cs_running); file->update_status = us_success; notice_finished_file (file); return; } /* First set the automatic variables according to this file. */ initialize_file_variables (file, 0); #if defined(CONFIG_WITH_COMMANDS_FUNC) || defined (CONFIG_WITH_DOT_MUST_MAKE) set_file_variables (file, 0 /* final call */); #else set_file_variables (file); #endif /* If this is a loaded dynamic object, unload it before remaking. Some systems don't support overwriting a loaded object. */ if (file->loaded) unload_file (file->name); /* Start the commands running. */ new_job (file); } /* This is set while we are inside fatal_error_signal, so things can avoid nonreentrant operations. */ int handling_fatal_signal = 0; /* Handle fatal signals. */ RETSIGTYPE fatal_error_signal (int sig) { #ifdef __MSDOS__ extern int dos_status, dos_command_running; if (dos_command_running) { /* That was the child who got the signal, not us. */ dos_status |= (sig << 8); return; } remove_intermediates (1); exit (EXIT_FAILURE); #else /* not __MSDOS__ */ #ifdef _AMIGA remove_intermediates (1); if (sig == SIGINT) fputs (_("*** Break.\n"), stderr); exit (10); #else /* not Amiga */ #if defined (WINDOWS32) && !defined (CONFIG_NEW_WIN32_CTRL_EVENT) extern HANDLE main_thread; /* Windows creates a sperate thread for handling Ctrl+C, so we need to suspend the main thread, or else we will have race conditions when both threads call reap_children. */ if (main_thread) { DWORD susp_count = SuspendThread (main_thread); if (susp_count != 0) fprintf (stderr, "SuspendThread: suspend count = %ld\n", susp_count); else if (susp_count == (DWORD)-1) { DWORD ierr = GetLastError (); fprintf (stderr, "SuspendThread: error %ld: %s\n", ierr, map_windows32_error_to_string (ierr)); } } #endif handling_fatal_signal = 1; /* Set the handling for this signal to the default. It is blocked now while we run this handler. */ signal (sig, SIG_DFL); /* A termination signal won't be sent to the entire process group, but it means we want to kill the children. */ if (sig == SIGTERM) { struct child *c; for (c = children; c != 0; c = c->next) if (!c->remote) # if defined (CONFIG_NEW_WIN_CHILDREN) && defined (WINDOWS32) MkWinChildKill (c->pid, SIGTERM, c); # else (void) kill (c->pid, SIGTERM); # endif } /* If we got a signal that means the user wanted to kill make, remove pending targets. */ if (sig == SIGTERM || sig == SIGINT #ifdef SIGHUP || sig == SIGHUP #endif #ifdef SIGQUIT || sig == SIGQUIT #endif ) { struct child *c; /* Remote children won't automatically get signals sent to the process group, so we must send them. */ for (c = children; c != 0; c = c->next) if (c->remote) (void) remote_kill (c->pid, sig); for (c = children; c != 0; c = c->next) delete_child_targets (c); /* Clean up the children. We don't just use the call below because we don't want to print the "Waiting for children" message. */ while (job_slots_used > 0) reap_children (1, 0); } else /* Wait for our children to die. */ while (job_slots_used > 0) reap_children (1, 1); /* Delete any non-precious intermediate files that were made. */ remove_intermediates (1); #ifdef SIGQUIT if (sig == SIGQUIT) /* We don't want to send ourselves SIGQUIT, because it will cause a core dump. Just exit instead. */ exit (MAKE_TROUBLE); #endif #ifdef WINDOWS32 # ifndef CONFIG_NEW_WIN32_CTRL_EVENT if (main_thread) CloseHandle (main_thread); # endif /* !CONFIG_NEW_WIN32_CTRL_EVENT */ /* Cannot call W32_kill with a pid (it needs a handle). The exit status of 130 emulates what happens in Bash. */ exit (130); #else /* Signal the same code; this time it will really be fatal. The signal will be unblocked when we return and arrive then to kill us. */ if (kill (getpid (), sig) < 0) pfatal_with_name ("kill"); #endif /* not WINDOWS32 */ #endif /* not Amiga */ #endif /* not __MSDOS__ */ } /* Delete FILE unless it's precious or not actually a file (phony), and it has changed on disk since we last stat'd it. */ static void delete_target (struct file *file, const char *on_behalf_of) { struct stat st; int e; if (file->precious || file->phony) return; #ifdef CONFIG_WITH_EXPLICIT_MULTITARGET assert (!file->multi_maybe); #endif #ifndef NO_ARCHIVES if (ar_name (file->name)) { time_t file_date = (file->last_mtime == NONEXISTENT_MTIME ? (time_t) -1 : (time_t) FILE_TIMESTAMP_S (file->last_mtime)); if (ar_member_date (file->name) != file_date) { if (on_behalf_of) OSS (error, NILF, _("*** [%s] Archive member '%s' may be bogus; not deleted"), on_behalf_of, file->name); else OS (error, NILF, _("*** Archive member '%s' may be bogus; not deleted"), file->name); } return; } #endif EINTRLOOP (e, stat (file->name, &st)); if (e == 0 && S_ISREG (st.st_mode) && FILE_TIMESTAMP_STAT_MODTIME (file->name, st) != file->last_mtime) { if (on_behalf_of) OSS (error, NILF, _("*** [%s] Deleting file '%s'"), on_behalf_of, file->name); else OS (error, NILF, _("*** Deleting file '%s'"), file->name); if (unlink (file->name) < 0 && errno != ENOENT) /* It disappeared; so what. */ perror_with_name ("unlink: ", file->name); } } /* Delete all non-precious targets of CHILD unless they were already deleted. Set the flag in CHILD to say they've been deleted. */ void delete_child_targets (struct child *child) { struct dep *d; if (child->deleted) return; /* Delete the target file if it changed. */ delete_target (child->file, NULL); /* Also remove any non-precious targets listed in the 'also_make' member. */ for (d = child->file->also_make; d != 0; d = d->next) delete_target (d->file, child->file->name); #ifdef CONFIG_WITH_EXPLICIT_MULTITARGET /* Also remove any multi target siblings, except for the 'maybe' ones (we handle that here) and precious ones (delete_target deals with that). Note that CHILD is always the multi target head (see remake.c). */ if (child->file == child->file->multi_head) { struct file *f2; for (f2 = child->file->multi_next; f2; f2 = f2->multi_next) if (!f2->multi_maybe) delete_target (f2, child->file->name); } #endif child->deleted = 1; } /* Print out the commands in CMDS. */ void print_commands (const struct commands *cmds) { const char *s; fputs (_("# recipe to execute"), stdout); if (cmds->fileinfo.filenm == 0) puts (_(" (built-in):")); else printf (_(" (from '%s', line %lu):\n"), cmds->fileinfo.filenm, cmds->fileinfo.lineno); s = cmds->commands; while (*s != '\0') { const char *end; int bs; /* Print one full logical recipe line: find a non-escaped newline. */ for (end = s, bs = 0; *end != '\0'; ++end) { if (*end == '\n' && !bs) break; bs = *end == '\\' ? !bs : 0; } printf ("%c%.*s\n", cmd_prefix, (int) (end - s), s); s = end + (end[0] == '\n'); } }