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#include "config.h"
#include <stdio.h>
#include <string.h>
/**
* tal - compact tree allocator routines (inspired by talloc)
*
* Tal is a hierarchical allocator; any pointer allocated by tal can
* become the parent of another allocation. When you free that parent,
* the children (and grandchildren, etc) are automatically freed.
*
* This allows you to build complex objects based on their lifetimes, eg:
*
* struct foo *X = tal(NULL, struct foo);
* X->val = tal(X, int);
*
* and the pointer X->val would be a "child" of the tal context "X";
* tal_free(X->val) would free X->val as expected, by tal_free(X) would
* free X and X->val.
*
* With an overhead of approximately 4 pointers per object
* (vs. talloc's 12 pointers), it uses dynamic allocation for
* destructors and child lists, so those operations can fail. It does
* not support talloc's references or failing destructors.
*
* See Also:
* ccan/tal/str (useful string helpers)
*
* Example:
* #include <stdio.h>
* #include <err.h>
* #include <ccan/talloc/talloc.h>
*
* // A structure containing a popened command.
* struct command {
* FILE *f;
* char *command;
* };
*
* // When struct command is freed, we also want to pclose pipe.
* static void close_cmd(struct command *cmd)
* {
* pclose(cmd->f);
* }
*
* // This function opens a writable pipe to the given command.
* static struct command *open_output_cmd(const tal_t *ctx,
* const char *a0, const char *a1)
* {
* struct command *cmd = tal(ctx, struct command);
*
* if (!cmd)
* return NULL;
*
* // Note that tal/str has helpers to make this much easier!
* cmd->command = tal_arrz(cmd, char, strlen(a0) + strlen(a1) + 2);
* if (!cmd->command) {
* tal_free(cmd);
* return NULL;
* }
* strcat(cmd->command, a0);
* strcat(cmd->command, " ");
* strcat(cmd->command, a1);
*
* cmd->f = popen(cmd->command, "w");
* if (!cmd->f) {
* tal_free(cmd);
* return NULL;
* }
* tal_add_destructor(cmd, close_cmd);
* return cmd;
* }
*
* int main(int argc, char *argv[])
* {
* struct command *cmd;
*
* if (argc != 2)
* errx(1, "Usage: %s <command>\n", argv[0]);
*
* cmd = open_output_cmd(NULL, argv[1], "hello");
* if (!cmd)
* err(1, "Running '%s hello'", argv[1]);
* fprintf(cmd->f, "This is a test\n");
* tal_free(cmd);
* return 0;
* }
*
* License: BSD-MIT
*/
int main(int argc, char *argv[])
{
if (argc != 2)
return 1;
if (strcmp(argv[1], "depends") == 0) {
printf("ccan/alignof\n");
printf("ccan/compiler\n");
printf("ccan/likely\n");
printf("ccan/list\n");
printf("ccan/str\n");
printf("ccan/take\n");
printf("ccan/typesafe_cb\n");
return 0;
}
return 1;
}
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