Three additional utility programsOptions, SkipArg, and GetArgsare sufficiently useful to list here. None, however, is dependent on Win32.
This function scans the command line for words with the "-" (hyphen) prefix, examines the individual characters, and sets Boolean parameters. It is similar to the UNIX getopt function, but it is not as powerful.
/* Utility function to extract option flags from the command line. */
#include "EvryThng.h"
#include <stdarg.h>
DWORD Options (int argc, LPCTSTR argv [], LPCTSTR OptStr, ...)
/* argv is the command line. The options, if any, start
with a '-' in argv [1], argv [2], ....
OptStr is a text string containing all possible
options, in one-to-one correspondence with the addresses of
Boolean variables in the variable argument list (...). These
flags are set if and only if the corresponding option character
occurs in argv [1], argv [2], .... The return value is the argv
index of the first argument beyond the options. */
{
va_list pFlagList;
LPBOOL pFlag;
int iFlag = 0, iArg;
va_start (pFlagList, OptStr);
while ((pFlag = va_arg (pFlagList, LPBOOL)) != NULL
&& iFlag < (int) _tcslen (OptStr)) {
*pFlag = FALSE;
for (iArg = 1;
!(*pFlag) && iArg < argc &&
argv [iArg] [0] == '-';
iArg++)
*pFlag = _memtchr (argv [iArg], OptStr [iFlag],
_tcslen (argv [iArg])) != NULL;
iFlag++;
}
va_end (pFlagList);
for (iArg = 1; iArg < argc && argv [iArg] [0] == '-'; iArg++);
return iArg;
}
This function processes a command line string to skip over a white-space-delimited field. It is first used in timep, Program 6-2.
/* SkipArg.c
Skip one command line argument -- skip tabs and spaces. */
#include "EvryThng.h"
LPTSTR SkipArg (LPCTSTR targv)
{
LPTSTR p;
p = (LPTSTR) targv;
/* Skip up to the next tab or space. */
while (*p != '\0' && *p != TSPACE && *p != TAB) p++;
/* Skip over tabs and spaces to the next arg. */
while (*p != '\0' && (*p == TSPACE || *p == TAB)) p++;
return p;
}
This function scans a string for space- and tab-delimited words and puts the results in a string array passed to the function. It is useful for converting a command line string into an argv [] array, and it is used initially with JobShell in Chapter 6. The Win32 function CommandLineToArgvW performs the same function but is limited to Unicode characters.
/* GetArgs. Put command line string in argc/argv form. */
#include "EvryThng.h"
VOID GetArgs (LPCTSTR Command, int *pArgc, LPTSTR argstr [])
{
int i, icm = 0;
DWORD ic = 0;
for (i = 0; ic < _tcslen (Command); i++) {
while (ic < _tcslen (Command) &&
Command [ic] != TSPACE && Command [ic] != TAB) {
argstr [i] [icm] = Command [ic];
ic++; icm++;
}
argstr [i] [icm] = '\0';
while (ic < _tcslen (Command) &&
(Command [ic] == TSPACE || Command [ic] == TAB))
ic++;
icm = 0;
}
if (pArgc != NULL) *pArgc = i;
return;
}