argv.c

[詳解]

/*++
/* NAME
/*  argv 3
/* SUMMARY
/*  string array utilities
/* SYNOPSIS
/*  #include <argv.h>
/*
/*  ARGV    *argv_alloc(len)
/*  ssize_t len;
/*
/*  ARGV    *argv_sort(argvp)
/*  ARGV    *argvp;
/*
/*  ARGV    *argv_free(argvp)
/*  ARGV    *argvp;
/*
/*  void    argv_add(argvp, arg, ..., ARGV_END)
/*  ARGV    *argvp;
/*  char    *arg;
/*
/*  void    argv_addn(argvp, arg, arg_len, ..., ARGV_END)
/*  ARGV    *argvp;
/*  char    *arg;
/*  ssize_t arg_len;
/*
/*  void    argv_terminate(argvp);
/*  ARGV    *argvp;
/*
/*  void    argv_truncate(argvp, len);
/*  ARGV    *argvp;
/*  ssize_t len;
/*
/*  void    argv_insert_one(argvp, pos, arg)
/*  ARGV    *argvp;
/*  ssize_t pos;
/*  const char *arg;
/*
/*  void    argv_replace_one(argvp, pos, arg)
/*  ARGV    *argvp;
/*  ssize_t pos;
/*  const char *arg;
/*
/*  void    argv_delete(argvp, pos, how_many)
/*  ARGV    *argvp;
/*  ssize_t pos;
/*  ssize_t how_many;
/*
/*  void    ARGV_FAKE_BEGIN(argv, arg)
/*  const char *arg;
/*
/*  void    ARGV_FAKE_END
/* DESCRIPTION
/*  The functions in this module manipulate arrays of string
/*  pointers. An ARGV structure contains the following members:
/* .IP len
/*  The length of the \fIargv\fR array member.
/* .IP argc
/*  The number of \fIargv\fR elements used.
/* .IP argv
/*  An array of pointers to null-terminated strings.
/* .PP
/*  argv_alloc() returns an empty string array of the requested
/*  length. The result is ready for use by argv_add(). The array
/*  is null terminated.
/*
/*  argv_sort() sorts the elements of argvp in place returning
/*  the original array.
/*
/*  argv_add() copies zero or more strings and adds them to the
/*  specified string array. The array is null terminated.
/*  Terminate the argument list with a null pointer. The manifest
/*  constant ARGV_END provides a convenient notation for this.
/*
/*  argv_addn() is like argv_add(), but each string is followed
/*  by a string length argument.
/*
/*  argv_free() releases storage for a string array, and conveniently
/*  returns a null pointer.
/*
/*  argv_terminate() null-terminates its string array argument.
/*
/*  argv_truncate() trucates its argument to the specified
/*  number of entries, but does not reallocate memory. The
/*  result is null-terminated.
/*
/*  argv_insert_one() inserts one string at the specified array
/*  position.
/*
/*  argv_replace_one() replaces one string at the specified
/*  position. The old string is destroyed after the update is
/*  made.
/*
/*  argv_delete() deletes the specified number of elements
/*  starting at the specified array position. The result is
/*  null-terminated.
/*
/*  ARGV_FAKE_BEGIN/END are an optimization for the case where
/*  a single string needs to be passed into an ARGV-based
/*  interface.  ARGV_FAKE_BEGIN() opens a statement block and
/*  allocates a stack-based ARGV structure named after the first
/*  argument, that encapsulates the second argument.  This
/*  implementation allocates no heap memory and creates no copy
/*  of the second argument.  ARGV_FAKE_END closes the statement
/*  block and thereby releases storage.
/* SEE ALSO
/*  msg(3) diagnostics interface
/* DIAGNOSTICS
/*  Fatal errors: memory allocation problem.
/* LICENSE
/* .ad
/* .fi
/*  The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*--*/

/* System libraries. */

#include <sys_defs.h>
#include <stdlib.h>         /* 44BSD stdarg.h uses abort() */
#include <stdarg.h>
#include <string.h>

/* Application-specific. */

#include "mymalloc.h"
#include "msg.h"
#include "argv.h"

/* argv_free - destroy string array */

ARGV   *argv_free(ARGV *argvp)
{
    char  **cpp;

    for (cpp = argvp->argv; cpp < argvp->argv + argvp->argc; cpp++)
    myfree(*cpp);
    myfree((void *) argvp->argv);
    myfree((void *) argvp);
    return (0);
}

/* argv_alloc - initialize string array */

ARGV   *argv_alloc(ssize_t len)
{
    ARGV   *argvp;
    ssize_t sane_len;

    /*
     * Make sure that always argvp->argc < argvp->len.
     */
    argvp = (ARGV *) mymalloc(sizeof(*argvp));
    argvp->len = 0;
    sane_len = (len < 2 ? 2 : len);
    argvp->argv = (char **) mymalloc((sane_len + 1) * sizeof(char *));
    argvp->len = sane_len;
    argvp->argc = 0;
    argvp->argv[0] = 0;
    return (argvp);
}

static int argv_cmp(const void *e1, const void *e2)
{
    const char *s1 = *(const char **) e1;
    const char *s2 = *(const char **) e2;

    return strcmp(s1, s2);
}

/* argv_sort - sort array in place */

ARGV   *argv_sort(ARGV *argvp)
{
    qsort(argvp->argv, argvp->argc, sizeof(argvp->argv[0]), argv_cmp);
    return (argvp);
}

/* argv_extend - extend array */

static void argv_extend(ARGV *argvp)
{
    ssize_t new_len;

    new_len = argvp->len * 2;
    argvp->argv = (char **)
    myrealloc((void *) argvp->argv, (new_len + 1) * sizeof(char *));
    argvp->len = new_len;
}

/* argv_add - add string to vector */

void    argv_add(ARGV *argvp,...)
{
    char   *arg;
    va_list ap;

    /*
     * Make sure that always argvp->argc < argvp->len.
     */
#define ARGV_SPACE_LEFT(a) ((a)->len - (a)->argc - 1)

    va_start(ap, argvp);
    while ((arg = va_arg(ap, char *)) != 0) {
    if (ARGV_SPACE_LEFT(argvp) <= 0)
        argv_extend(argvp);
    argvp->argv[argvp->argc++] = mystrdup(arg);
    }
    va_end(ap);
    argvp->argv[argvp->argc] = 0;
}

/* argv_addn - add string to vector */

void    argv_addn(ARGV *argvp,...)
{
    char   *arg;
    ssize_t len;
    va_list ap;

    /*
     * Make sure that always argvp->argc < argvp->len.
     */
    va_start(ap, argvp);
    while ((arg = va_arg(ap, char *)) != 0) {
    if ((len = va_arg(ap, ssize_t)) < 0)
        msg_panic("argv_addn: bad string length %ld", (long) len);
    if (ARGV_SPACE_LEFT(argvp) <= 0)
        argv_extend(argvp);
    argvp->argv[argvp->argc++] = mystrndup(arg, len);
    }
    va_end(ap);
    argvp->argv[argvp->argc] = 0;
}

/* argv_terminate - terminate string array */

void    argv_terminate(ARGV *argvp)
{

    /*
     * Trust that argvp->argc < argvp->len.
     */
    argvp->argv[argvp->argc] = 0;
}

/* argv_truncate - truncate string array */

void    argv_truncate(ARGV *argvp, ssize_t len)
{
    char  **cpp;

    /*
     * Sanity check.
     */
    if (len < 0)
    msg_panic("argv_truncate: bad length %ld", (long) len);

    if (len < argvp->argc) {
    for (cpp = argvp->argv + len; cpp < argvp->argv + argvp->argc; cpp++)
        myfree(*cpp);
    argvp->argc = len;
    argvp->argv[argvp->argc] = 0;
    }
}

/* argv_insert_one - insert one string into array */

void    argv_insert_one(ARGV *argvp, ssize_t where, const char *arg)
{
    ssize_t pos;

    /*
     * Sanity check.
     */
    if (where < 0 || where > argvp->argc)
    msg_panic("argv_insert_one bad position: %ld", (long) where);

    if (ARGV_SPACE_LEFT(argvp) <= 0)
    argv_extend(argvp);
    for (pos = argvp->argc; pos >= where; pos--)
    argvp->argv[pos + 1] = argvp->argv[pos];
    argvp->argv[where] = mystrdup(arg);
    argvp->argc += 1;
}

/* argv_replace_one - replace one string in array */

void    argv_replace_one(ARGV *argvp, ssize_t where, const char *arg)
{
    char   *temp;

    /*
     * Sanity check.
     */
    if (where < 0 || where >= argvp->argc)
    msg_panic("argv_replace_one bad position: %ld", (long) where);

    temp = argvp->argv[where];
    argvp->argv[where] = mystrdup(arg);
    myfree(temp);
}

/* argv_delete - remove string(s) from array */

void    argv_delete(ARGV *argvp, ssize_t first, ssize_t how_many)
{
    ssize_t pos;

    /*
     * Sanity check.
     */
    if (first < 0 || how_many < 0 || first + how_many > argvp->argc)
    msg_panic("argv_delete bad range: (start=%ld count=%ld)",
          (long) first, (long) how_many);

    for (pos = first; pos < first + how_many; pos++)
    myfree(argvp->argv[pos]);
    for (pos = first; pos <= argvp->argc - how_many; pos++)
    argvp->argv[pos] = argvp->argv[pos + how_many];
    argvp->argc -= how_many;
}