diff -r d59bea55db9b -r c445c931472f src/glpcpx.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/glpcpx.c	Mon Dec 06 13:09:21 2010 +0100
@@ -0,0 +1,1239 @@
+/* glpcpx.c (CPLEX LP format routines) */
+
+/***********************************************************************
+*  This code is part of GLPK (GNU Linear Programming Kit).
+*
+*  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
+*  2009, 2010 Andrew Makhorin, Department for Applied Informatics,
+*  Moscow Aviation Institute, Moscow, Russia. All rights reserved.
+*  E-mail: <mao@gnu.org>.
+*
+*  GLPK 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.
+*
+*  GLPK 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 GLPK. If not, see <http://www.gnu.org/licenses/>.
+***********************************************************************/
+
+#include "glpapi.h"
+
+/***********************************************************************
+*  NAME
+*
+*  glp_init_cpxcp - initialize CPLEX LP format control parameters
+*
+*  SYNOPSIS
+*
+*  void glp_init_cpxcp(glp_cpxcp *parm):
+*
+*  The routine glp_init_cpxcp initializes control parameters used by
+*  the CPLEX LP input/output routines glp_read_lp and glp_write_lp with
+*  default values.
+*
+*  Default values of the control parameters are stored in the glp_cpxcp
+*  structure, which the parameter parm points to. */
+
+void glp_init_cpxcp(glp_cpxcp *parm)
+{     xassert(parm != NULL);
+      return;
+}
+
+static void check_parm(const char *func, const glp_cpxcp *parm)
+{     /* check control parameters */
+      xassert(func != NULL);
+      xassert(parm != NULL);
+      return;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_read_lp - read problem data in CPLEX LP format
+*
+*  SYNOPSIS
+*
+*  int glp_read_lp(glp_prob *P, const glp_cpxcp *parm, const char
+*     *fname);
+*
+*  DESCRIPTION
+*
+*  The routine glp_read_lp reads problem data in CPLEX LP format from
+*  a text file.
+*
+*  The parameter parm is a pointer to the structure glp_cpxcp, which
+*  specifies control parameters used by the routine. If parm is NULL,
+*  the routine uses default settings.
+*
+*  The character string fname specifies a name of the text file to be
+*  read.
+*
+*  Note that before reading data the current content of the problem
+*  object is completely erased with the routine glp_erase_prob.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine glp_read_lp returns
+*  zero. Otherwise, it prints an error message and returns non-zero. */
+
+struct csa
+{     /* common storage area */
+      glp_prob *P;
+      /* LP/MIP problem object */
+      const glp_cpxcp *parm;
+      /* pointer to control parameters */
+      const char *fname;
+      /* name of input CPLEX LP file */
+      XFILE *fp;
+      /* stream assigned to input CPLEX LP file */
+      jmp_buf jump;
+      /* label for go to in case of error */
+      int count;
+      /* line count */
+      int c;
+      /* current character or XEOF */
+      int token;
+      /* current token: */
+#define T_EOF        0x00  /* end of file */
+#define T_MINIMIZE   0x01  /* keyword 'minimize' */
+#define T_MAXIMIZE   0x02  /* keyword 'maximize' */
+#define T_SUBJECT_TO 0x03  /* keyword 'subject to' */
+#define T_BOUNDS     0x04  /* keyword 'bounds' */
+#define T_GENERAL    0x05  /* keyword 'general' */
+#define T_INTEGER    0x06  /* keyword 'integer' */
+#define T_BINARY     0x07  /* keyword 'binary' */
+#define T_END        0x08  /* keyword 'end' */
+#define T_NAME       0x09  /* symbolic name */
+#define T_NUMBER     0x0A  /* numeric constant */
+#define T_PLUS       0x0B  /* delimiter '+' */
+#define T_MINUS      0x0C  /* delimiter '-' */
+#define T_COLON      0x0D  /* delimiter ':' */
+#define T_LE         0x0E  /* delimiter '<=' */
+#define T_GE         0x0F  /* delimiter '>=' */
+#define T_EQ         0x10  /* delimiter '=' */
+      char image[255+1];
+      /* image of current token */
+      int imlen;
+      /* length of token image */
+      double value;
+      /* value of numeric constant */
+      int n_max;
+      /* length of the following five arrays (enlarged automatically,
+         if necessary) */
+      int *ind; /* int ind[1+n_max]; */
+      double *val; /* double val[1+n_max]; */
+      char *flag; /* char flag[1+n_max]; */
+      /* working arrays used to construct linear forms */
+      double *lb; /* double lb[1+n_max]; */
+      double *ub; /* double ub[1+n_max]; */
+      /* lower and upper bounds of variables (columns) */
+};
+
+#define CHAR_SET "!\"#$%&()/,.;?@_`'{}|~"
+/* characters, which may appear in symbolic names */
+
+static void error(struct csa *csa, const char *fmt, ...)
+{     /* print error message and terminate processing */
+      va_list arg;
+      xprintf("%s:%d: ", csa->fname, csa->count);
+      va_start(arg, fmt);
+      xvprintf(fmt, arg);
+      va_end(arg);
+      longjmp(csa->jump, 1);
+      /* no return */
+}
+
+static void warning(struct csa *csa, const char *fmt, ...)
+{     /* print warning message and continue processing */
+      va_list arg;
+      xprintf("%s:%d: warning: ", csa->fname, csa->count);
+      va_start(arg, fmt);
+      xvprintf(fmt, arg);
+      va_end(arg);
+      return;
+}
+
+static void read_char(struct csa *csa)
+{     /* read next character from input file */
+      int c;
+      xassert(csa->c != XEOF);
+      if (csa->c == '\n') csa->count++;
+      c = xfgetc(csa->fp);
+      if (c < 0)
+      {  if (xferror(csa->fp))
+            error(csa, "read error - %s\n", xerrmsg());
+         else if (csa->c == '\n')
+         {  csa->count--;
+            c = XEOF;
+         }
+         else
+         {  warning(csa, "missing final end of line\n");
+            c = '\n';
+         }
+      }
+      else if (c == '\n')
+         ;
+      else if (isspace(c))
+         c = ' ';
+      else if (iscntrl(c))
+         error(csa, "invalid control character 0x%02X\n", c);
+      csa->c = c;
+      return;
+}
+
+static void add_char(struct csa *csa)
+{     /* append current character to current token */
+      if (csa->imlen == sizeof(csa->image)-1)
+         error(csa, "token `%.15s...' too long\n", csa->image);
+      csa->image[csa->imlen++] = (char)csa->c;
+      csa->image[csa->imlen] = '\0';
+      read_char(csa);
+      return;
+}
+
+static int the_same(char *s1, char *s2)
+{     /* compare two character strings ignoring case sensitivity */
+      for (; *s1 != '\0'; s1++, s2++)
+      {  if (tolower((unsigned char)*s1) != tolower((unsigned char)*s2))
+            return 0;
+      }
+      return 1;
+}
+
+static void scan_token(struct csa *csa)
+{     /* scan next token */
+      int flag;
+      csa->token = -1;
+      csa->image[0] = '\0';
+      csa->imlen = 0;
+      csa->value = 0.0;
+loop: flag = 0;
+      /* skip non-significant characters */
+      while (csa->c == ' ') read_char(csa);
+      /* recognize and scan current token */
+      if (csa->c == XEOF)
+         csa->token = T_EOF;
+      else if (csa->c == '\n')
+      {  read_char(csa);
+         /* if the next character is letter, it may begin a keyword */
+         if (isalpha(csa->c))
+         {  flag = 1;
+            goto name;
+         }
+         goto loop;
+      }
+      else if (csa->c == '\\')
+      {  /* comment; ignore everything until end-of-line */
+         while (csa->c != '\n') read_char(csa);
+         goto loop;
+      }
+      else if (isalpha(csa->c) || csa->c != '.' && strchr(CHAR_SET,
+         csa->c) != NULL)
+name: {  /* symbolic name */
+         csa->token = T_NAME;
+         while (isalnum(csa->c) || strchr(CHAR_SET, csa->c) != NULL)
+            add_char(csa);
+         if (flag)
+         {  /* check for keyword */
+            if (the_same(csa->image, "minimize"))
+               csa->token = T_MINIMIZE;
+            else if (the_same(csa->image, "minimum"))
+               csa->token = T_MINIMIZE;
+            else if (the_same(csa->image, "min"))
+               csa->token = T_MINIMIZE;
+            else if (the_same(csa->image, "maximize"))
+               csa->token = T_MAXIMIZE;
+            else if (the_same(csa->image, "maximum"))
+               csa->token = T_MAXIMIZE;
+            else if (the_same(csa->image, "max"))
+               csa->token = T_MAXIMIZE;
+            else if (the_same(csa->image, "subject"))
+            {  if (csa->c == ' ')
+               {  read_char(csa);
+                  if (tolower(csa->c) == 't')
+                  {  csa->token = T_SUBJECT_TO;
+                     csa->image[csa->imlen++] = ' ';
+                     csa->image[csa->imlen] = '\0';
+                     add_char(csa);
+                     if (tolower(csa->c) != 'o')
+                        error(csa, "keyword `subject to' incomplete\n");
+                     add_char(csa);
+                     if (isalpha(csa->c))
+                        error(csa, "keyword `%s%c...' not recognized\n",
+                           csa->image, csa->c);
+                  }
+               }
+            }
+            else if (the_same(csa->image, "such"))
+            {  if (csa->c == ' ')
+               {  read_char(csa);
+                  if (tolower(csa->c) == 't')
+                  {  csa->token = T_SUBJECT_TO;
+                     csa->image[csa->imlen++] = ' ';
+                     csa->image[csa->imlen] = '\0';
+                     add_char(csa);
+                     if (tolower(csa->c) != 'h')
+err:                    error(csa, "keyword `such that' incomplete\n");
+                     add_char(csa);
+                     if (tolower(csa->c) != 'a') goto err;
+                     add_char(csa);
+                     if (tolower(csa->c) != 't') goto err;
+                     add_char(csa);
+                     if (isalpha(csa->c))
+                        error(csa, "keyword `%s%c...' not recognized\n",
+                           csa->image, csa->c);
+                  }
+               }
+            }
+            else if (the_same(csa->image, "st"))
+               csa->token = T_SUBJECT_TO;
+            else if (the_same(csa->image, "s.t."))
+               csa->token = T_SUBJECT_TO;
+            else if (the_same(csa->image, "st."))
+               csa->token = T_SUBJECT_TO;
+            else if (the_same(csa->image, "bounds"))
+               csa->token = T_BOUNDS;
+            else if (the_same(csa->image, "bound"))
+               csa->token = T_BOUNDS;
+            else if (the_same(csa->image, "general"))
+               csa->token = T_GENERAL;
+            else if (the_same(csa->image, "generals"))
+               csa->token = T_GENERAL;
+            else if (the_same(csa->image, "gen"))
+               csa->token = T_GENERAL;
+            else if (the_same(csa->image, "integer"))
+               csa->token = T_INTEGER;
+            else if (the_same(csa->image, "integers"))
+               csa->token = T_INTEGER;
+            else if (the_same(csa->image, "int"))
+              csa->token = T_INTEGER;
+            else if (the_same(csa->image, "binary"))
+               csa->token = T_BINARY;
+            else if (the_same(csa->image, "binaries"))
+               csa->token = T_BINARY;
+            else if (the_same(csa->image, "bin"))
+               csa->token = T_BINARY;
+            else if (the_same(csa->image, "end"))
+               csa->token = T_END;
+         }
+      }
+      else if (isdigit(csa->c) || csa->c == '.')
+      {  /* numeric constant */
+         csa->token = T_NUMBER;
+         /* scan integer part */
+         while (isdigit(csa->c)) add_char(csa);
+         /* scan optional fractional part (it is mandatory, if there is
+            no integer part) */
+         if (csa->c == '.')
+         {  add_char(csa);
+            if (csa->imlen == 1 && !isdigit(csa->c))
+               error(csa, "invalid use of decimal point\n");
+            while (isdigit(csa->c)) add_char(csa);
+         }
+         /* scan optional decimal exponent */
+         if (csa->c == 'e' || csa->c == 'E')
+         {  add_char(csa);
+            if (csa->c == '+' || csa->c == '-') add_char(csa);
+            if (!isdigit(csa->c))
+               error(csa, "numeric constant `%s' incomplete\n",
+                  csa->image);
+            while (isdigit(csa->c)) add_char(csa);
+         }
+         /* convert the numeric constant to floating-point */
+         if (str2num(csa->image, &csa->value))
+            error(csa, "numeric constant `%s' out of range\n",
+               csa->image);
+      }
+      else if (csa->c == '+')
+         csa->token = T_PLUS, add_char(csa);
+      else if (csa->c == '-')
+         csa->token = T_MINUS, add_char(csa);
+      else if (csa->c == ':')
+         csa->token = T_COLON, add_char(csa);
+      else if (csa->c == '<')
+      {  csa->token = T_LE, add_char(csa);
+         if (csa->c == '=') add_char(csa);
+      }
+      else if (csa->c == '>')
+      {  csa->token = T_GE, add_char(csa);
+         if (csa->c == '=') add_char(csa);
+      }
+      else if (csa->c == '=')
+      {  csa->token = T_EQ, add_char(csa);
+         if (csa->c == '<')
+            csa->token = T_LE, add_char(csa);
+         else if (csa->c == '>')
+            csa->token = T_GE, add_char(csa);
+      }
+      else
+         error(csa, "character `%c' not recognized\n", csa->c);
+      /* skip non-significant characters */
+      while (csa->c == ' ') read_char(csa);
+      return;
+}
+
+static int find_col(struct csa *csa, char *name)
+{     /* find column by its symbolic name */
+      int j;
+      j = glp_find_col(csa->P, name);
+      if (j == 0)
+      {  /* not found; create new column */
+         j = glp_add_cols(csa->P, 1);
+         glp_set_col_name(csa->P, j, name);
+         /* enlarge working arrays, if necessary */
+         if (csa->n_max < j)
+         {  int n_max = csa->n_max;
+            int *ind = csa->ind;
+            double *val = csa->val;
+            char *flag = csa->flag;
+            double *lb = csa->lb;
+            double *ub = csa->ub;
+            csa->n_max += csa->n_max;
+            csa->ind = xcalloc(1+csa->n_max, sizeof(int));
+            memcpy(&csa->ind[1], &ind[1], n_max * sizeof(int));
+            xfree(ind);
+            csa->val = xcalloc(1+csa->n_max, sizeof(double));
+            memcpy(&csa->val[1], &val[1], n_max * sizeof(double));
+            xfree(val);
+            csa->flag = xcalloc(1+csa->n_max, sizeof(char));
+            memset(&csa->flag[1], 0, csa->n_max * sizeof(char));
+            memcpy(&csa->flag[1], &flag[1], n_max * sizeof(char));
+            xfree(flag);
+            csa->lb = xcalloc(1+csa->n_max, sizeof(double));
+            memcpy(&csa->lb[1], &lb[1], n_max * sizeof(double));
+            xfree(lb);
+            csa->ub = xcalloc(1+csa->n_max, sizeof(double));
+            memcpy(&csa->ub[1], &ub[1], n_max * sizeof(double));
+            xfree(ub);
+         }
+         csa->lb[j] = +DBL_MAX, csa->ub[j] = -DBL_MAX;
+      }
+      return j;
+}
+
+/***********************************************************************
+*  parse_linear_form - parse linear form
+*
+*  This routine parses the linear form using the following syntax:
+*
+*  <variable> ::= <symbolic name>
+*  <coefficient> ::= <numeric constant>
+*  <term> ::= <variable> | <numeric constant> <variable>
+*  <linear form> ::= <term> | + <term> | - <term> |
+*     <linear form> + <term> | <linear form> - <term>
+*
+*  The routine returns the number of terms in the linear form. */
+
+static int parse_linear_form(struct csa *csa)
+{     int j, k, len = 0, newlen;
+      double s, coef;
+loop: /* parse an optional sign */
+      if (csa->token == T_PLUS)
+         s = +1.0, scan_token(csa);
+      else if (csa->token == T_MINUS)
+         s = -1.0, scan_token(csa);
+      else
+         s = +1.0;
+      /* parse an optional coefficient */
+      if (csa->token == T_NUMBER)
+         coef = csa->value, scan_token(csa);
+      else
+         coef = 1.0;
+      /* parse a variable name */
+      if (csa->token != T_NAME)
+         error(csa, "missing variable name\n");
+      /* find the corresponding column */
+      j = find_col(csa, csa->image);
+      /* check if the variable is already used in the linear form */
+      if (csa->flag[j])
+         error(csa, "multiple use of variable `%s' not allowed\n",
+            csa->image);
+      /* add new term to the linear form */
+      len++, csa->ind[len] = j, csa->val[len] = s * coef;
+      /* and mark that the variable is used in the linear form */
+      csa->flag[j] = 1;
+      scan_token(csa);
+      /* if the next token is a sign, there is another term */
+      if (csa->token == T_PLUS || csa->token == T_MINUS) goto loop;
+      /* clear marks of the variables used in the linear form */
+      for (k = 1; k <= len; k++) csa->flag[csa->ind[k]] = 0;
+      /* remove zero coefficients */
+      newlen = 0;
+      for (k = 1; k <= len; k++)
+      {  if (csa->val[k] != 0.0)
+         {  newlen++;
+            csa->ind[newlen] = csa->ind[k];
+            csa->val[newlen] = csa->val[k];
+         }
+      }
+      return newlen;
+}
+
+/***********************************************************************
+*  parse_objective - parse objective function
+*
+*  This routine parses definition of the objective function using the
+*  following syntax:
+*
+*  <obj sense> ::= minimize | minimum | min | maximize | maximum | max
+*  <obj name> ::= <empty> | <symbolic name> :
+*  <obj function> ::= <obj sense> <obj name> <linear form> */
+
+static void parse_objective(struct csa *csa)
+{     /* parse objective sense */
+      int k, len;
+      /* parse the keyword 'minimize' or 'maximize' */
+      if (csa->token == T_MINIMIZE)
+         glp_set_obj_dir(csa->P, GLP_MIN);
+      else if (csa->token == T_MAXIMIZE)
+         glp_set_obj_dir(csa->P, GLP_MAX);
+      else
+         xassert(csa != csa);
+      scan_token(csa);
+      /* parse objective name */
+      if (csa->token == T_NAME && csa->c == ':')
+      {  /* objective name is followed by a colon */
+         glp_set_obj_name(csa->P, csa->image);
+         scan_token(csa);
+         xassert(csa->token == T_COLON);
+         scan_token(csa);
+      }
+      else
+      {  /* objective name is not specified; use default */
+         glp_set_obj_name(csa->P, "obj");
+      }
+      /* parse linear form */
+      len = parse_linear_form(csa);
+      for (k = 1; k <= len; k++)
+         glp_set_obj_coef(csa->P, csa->ind[k], csa->val[k]);
+      return;
+}
+
+/***********************************************************************
+*  parse_constraints - parse constraints section
+*
+*  This routine parses the constraints section using the following
+*  syntax:
+*
+*  <row name> ::= <empty> | <symbolic name> :
+*  <row sense> ::= < | <= | =< | > | >= | => | =
+*  <right-hand side> ::= <numeric constant> | + <numeric constant> |
+*     - <numeric constant>
+*  <constraint> ::= <row name> <linear form> <row sense>
+*     <right-hand side>
+*  <subject to> ::= subject to | such that | st | s.t. | st.
+*  <constraints section> ::= <subject to> <constraint> |
+*     <constraints section> <constraint> */
+
+static void parse_constraints(struct csa *csa)
+{     int i, len, type;
+      double s;
+      /* parse the keyword 'subject to' */
+      xassert(csa->token == T_SUBJECT_TO);
+      scan_token(csa);
+loop: /* create new row (constraint) */
+      i = glp_add_rows(csa->P, 1);
+      /* parse row name */
+      if (csa->token == T_NAME && csa->c == ':')
+      {  /* row name is followed by a colon */
+         if (glp_find_row(csa->P, csa->image) != 0)
+            error(csa, "constraint `%s' multiply defined\n",
+               csa->image);
+         glp_set_row_name(csa->P, i, csa->image);
+         scan_token(csa);
+         xassert(csa->token == T_COLON);
+         scan_token(csa);
+      }
+      else
+      {  /* row name is not specified; use default */
+         char name[50];
+         sprintf(name, "r.%d", csa->count);
+         glp_set_row_name(csa->P, i, name);
+      }
+      /* parse linear form */
+      len = parse_linear_form(csa);
+      glp_set_mat_row(csa->P, i, len, csa->ind, csa->val);
+      /* parse constraint sense */
+      if (csa->token == T_LE)
+         type = GLP_UP, scan_token(csa);
+      else if (csa->token == T_GE)
+         type = GLP_LO, scan_token(csa);
+      else if (csa->token == T_EQ)
+         type = GLP_FX, scan_token(csa);
+      else
+         error(csa, "missing constraint sense\n");
+      /* parse right-hand side */
+      if (csa->token == T_PLUS)
+         s = +1.0, scan_token(csa);
+      else if (csa->token == T_MINUS)
+         s = -1.0, scan_token(csa);
+      else
+         s = +1.0;
+      if (csa->token != T_NUMBER)
+         error(csa, "missing right-hand side\n");
+      glp_set_row_bnds(csa->P, i, type, s * csa->value, s * csa->value);
+      /* the rest of the current line must be empty */
+      if (!(csa->c == '\n' || csa->c == XEOF))
+         error(csa, "invalid symbol(s) beyond right-hand side\n");
+      scan_token(csa);
+      /* if the next token is a sign, numeric constant, or a symbolic
+         name, here is another constraint */
+      if (csa->token == T_PLUS || csa->token == T_MINUS ||
+          csa->token == T_NUMBER || csa->token == T_NAME) goto loop;
+      return;
+}
+
+static void set_lower_bound(struct csa *csa, int j, double lb)
+{     /* set lower bound of j-th variable */
+      if (csa->lb[j] != +DBL_MAX)
+      {  warning(csa, "lower bound of variable `%s' redefined\n",
+            glp_get_col_name(csa->P, j));
+      }
+      csa->lb[j] = lb;
+      return;
+}
+
+static void set_upper_bound(struct csa *csa, int j, double ub)
+{     /* set upper bound of j-th variable */
+      if (csa->ub[j] != -DBL_MAX)
+      {  warning(csa, "upper bound of variable `%s' redefined\n",
+            glp_get_col_name(csa->P, j));
+      }
+      csa->ub[j] = ub;
+      return;
+}
+
+/***********************************************************************
+*  parse_bounds - parse bounds section
+*
+*  This routine parses the bounds section using the following syntax:
+*
+*  <variable> ::= <symbolic name>
+*  <infinity> ::= infinity | inf
+*  <bound> ::= <numeric constant> | + <numeric constant> |
+*     - <numeric constant> | + <infinity> | - <infinity>
+*  <lt> ::= < | <= | =<
+*  <gt> ::= > | >= | =>
+*  <bound definition> ::= <bound> <lt> <variable> <lt> <bound> |
+*     <bound> <lt> <variable> | <variable> <lt> <bound> |
+*     <variable> <gt> <bound> | <variable> = <bound> | <variable> free
+*  <bounds> ::= bounds | bound
+*  <bounds section> ::= <bounds> |
+*     <bounds section> <bound definition> */
+
+static void parse_bounds(struct csa *csa)
+{     int j, lb_flag;
+      double lb, s;
+      /* parse the keyword 'bounds' */
+      xassert(csa->token == T_BOUNDS);
+      scan_token(csa);
+loop: /* bound definition can start with a sign, numeric constant, or
+         a symbolic name */
+      if (!(csa->token == T_PLUS || csa->token == T_MINUS ||
+            csa->token == T_NUMBER || csa->token == T_NAME)) goto done;
+      /* parse bound definition */
+      if (csa->token == T_PLUS || csa->token == T_MINUS)
+      {  /* parse signed lower bound */
+         lb_flag = 1;
+         s = (csa->token == T_PLUS ? +1.0 : -1.0);
+         scan_token(csa);
+         if (csa->token == T_NUMBER)
+            lb = s * csa->value, scan_token(csa);
+         else if (the_same(csa->image, "infinity") ||
+                  the_same(csa->image, "inf"))
+         {  if (s > 0.0)
+               error(csa, "invalid use of `+inf' as lower bound\n");
+            lb = -DBL_MAX, scan_token(csa);
+         }
+         else
+            error(csa, "missing lower bound\n");
+      }
+      else if (csa->token == T_NUMBER)
+      {  /* parse unsigned lower bound */
+         lb_flag = 1;
+         lb = csa->value, scan_token(csa);
+      }
+      else
+      {  /* lower bound is not specified */
+         lb_flag = 0;
+      }
+      /* parse the token that should follow the lower bound */
+      if (lb_flag)
+      {  if (csa->token != T_LE)
+            error(csa, "missing `<', `<=', or `=<' after lower bound\n")
+               ;
+         scan_token(csa);
+      }
+      /* parse variable name */
+      if (csa->token != T_NAME)
+         error(csa, "missing variable name\n");
+      j = find_col(csa, csa->image);
+      /* set lower bound */
+      if (lb_flag) set_lower_bound(csa, j, lb);
+      scan_token(csa);
+      /* parse the context that follows the variable name */
+      if (csa->token == T_LE)
+      {  /* parse upper bound */
+         scan_token(csa);
+         if (csa->token == T_PLUS || csa->token == T_MINUS)
+         {  /* parse signed upper bound */
+            s = (csa->token == T_PLUS ? +1.0 : -1.0);
+            scan_token(csa);
+            if (csa->token == T_NUMBER)
+            {  set_upper_bound(csa, j, s * csa->value);
+               scan_token(csa);
+            }
+            else if (the_same(csa->image, "infinity") ||
+                     the_same(csa->image, "inf"))
+            {  if (s < 0.0)
+                  error(csa, "invalid use of `-inf' as upper bound\n");
+               set_upper_bound(csa, j, +DBL_MAX);
+               scan_token(csa);
+            }
+            else
+               error(csa, "missing upper bound\n");
+         }
+         else if (csa->token == T_NUMBER)
+         {  /* parse unsigned upper bound */
+            set_upper_bound(csa, j, csa->value);
+            scan_token(csa);
+         }
+         else
+            error(csa, "missing upper bound\n");
+      }
+      else if (csa->token == T_GE)
+      {  /* parse lower bound */
+         if (lb_flag)
+         {  /* the context '... <= x >= ...' is invalid */
+            error(csa, "invalid bound definition\n");
+         }
+         scan_token(csa);
+         if (csa->token == T_PLUS || csa->token == T_MINUS)
+         {  /* parse signed lower bound */
+            s = (csa->token == T_PLUS ? +1.0 : -1.0);
+            scan_token(csa);
+            if (csa->token == T_NUMBER)
+            {  set_lower_bound(csa, j, s * csa->value);
+               scan_token(csa);
+            }
+            else if (the_same(csa->image, "infinity") ||
+                     the_same(csa->image, "inf") == 0)
+            {  if (s > 0.0)
+                  error(csa, "invalid use of `+inf' as lower bound\n");
+               set_lower_bound(csa, j, -DBL_MAX);
+               scan_token(csa);
+            }
+            else
+               error(csa, "missing lower bound\n");
+         }
+         else if (csa->token == T_NUMBER)
+         {  /* parse unsigned lower bound */
+            set_lower_bound(csa, j, csa->value);
+            scan_token(csa);
+         }
+         else
+            error(csa, "missing lower bound\n");
+      }
+      else if (csa->token == T_EQ)
+      {  /* parse fixed value */
+         if (lb_flag)
+         {  /* the context '... <= x = ...' is invalid */
+            error(csa, "invalid bound definition\n");
+         }
+         scan_token(csa);
+         if (csa->token == T_PLUS || csa->token == T_MINUS)
+         {  /* parse signed fixed value */
+            s = (csa->token == T_PLUS ? +1.0 : -1.0);
+            scan_token(csa);
+            if (csa->token == T_NUMBER)
+            {  set_lower_bound(csa, j, s * csa->value);
+               set_upper_bound(csa, j, s * csa->value);
+               scan_token(csa);
+            }
+            else
+               error(csa, "missing fixed value\n");
+         }
+         else if (csa->token == T_NUMBER)
+         {  /* parse unsigned fixed value */
+            set_lower_bound(csa, j, csa->value);
+            set_upper_bound(csa, j, csa->value);
+            scan_token(csa);
+         }
+         else
+            error(csa, "missing fixed value\n");
+      }
+      else if (the_same(csa->image, "free"))
+      {  /* parse the keyword 'free' */
+         if (lb_flag)
+         {  /* the context '... <= x free ...' is invalid */
+            error(csa, "invalid bound definition\n");
+         }
+         set_lower_bound(csa, j, -DBL_MAX);
+         set_upper_bound(csa, j, +DBL_MAX);
+         scan_token(csa);
+      }
+      else if (!lb_flag)
+      {  /* neither lower nor upper bounds are specified */
+         error(csa, "invalid bound definition\n");
+      }
+      goto loop;
+done: return;
+}
+
+/***********************************************************************
+*  parse_integer - parse general, integer, or binary section
+*
+*  <variable> ::= <symbolic name>
+*  <general> ::= general | generals | gen
+*  <integer> ::= integer | integers | int
+*  <binary> ::= binary | binaries | bin
+*  <section head> ::= <general> <integer> <binary>
+*  <additional section> ::= <section head> |
+*     <additional section> <variable> */
+
+static void parse_integer(struct csa *csa)
+{     int j, binary;
+      /* parse the keyword 'general', 'integer', or 'binary' */
+      if (csa->token == T_GENERAL)
+         binary = 0, scan_token(csa);
+      else if (csa->token == T_INTEGER)
+         binary = 0, scan_token(csa);
+      else if (csa->token == T_BINARY)
+         binary = 1, scan_token(csa);
+      else
+         xassert(csa != csa);
+      /* parse list of variables (may be empty) */
+      while (csa->token == T_NAME)
+      {  /* find the corresponding column */
+         j = find_col(csa, csa->image);
+         /* change kind of the variable */
+         glp_set_col_kind(csa->P, j, GLP_IV);
+         /* set 0-1 bounds for the binary variable */
+         if (binary)
+         {  set_lower_bound(csa, j, 0.0);
+            set_upper_bound(csa, j, 1.0);
+         }
+         scan_token(csa);
+      }
+      return;
+}
+
+int glp_read_lp(glp_prob *P, const glp_cpxcp *parm, const char *fname)
+{     /* read problem data in CPLEX LP format */
+      glp_cpxcp _parm;
+      struct csa _csa, *csa = &_csa;
+      int ret;
+      xprintf("Reading problem data from `%s'...\n", fname);
+      if (parm == NULL)
+         glp_init_cpxcp(&_parm), parm = &_parm;
+      /* check control parameters */
+      check_parm("glp_read_lp", parm);
+      /* initialize common storage area */
+      csa->P = P;
+      csa->parm = parm;
+      csa->fname = fname;
+      csa->fp = NULL;
+      if (setjmp(csa->jump))
+      {  ret = 1;
+         goto done;
+      }
+      csa->count = 0;
+      csa->c = '\n';
+      csa->token = T_EOF;
+      csa->image[0] = '\0';
+      csa->imlen = 0;
+      csa->value = 0.0;
+      csa->n_max = 100;
+      csa->ind = xcalloc(1+csa->n_max, sizeof(int));
+      csa->val = xcalloc(1+csa->n_max, sizeof(double));
+      csa->flag = xcalloc(1+csa->n_max, sizeof(char));
+      memset(&csa->flag[1], 0, csa->n_max * sizeof(char));
+      csa->lb = xcalloc(1+csa->n_max, sizeof(double));
+      csa->ub = xcalloc(1+csa->n_max, sizeof(double));
+      /* erase problem object */
+      glp_erase_prob(P);
+      glp_create_index(P);
+      /* open input CPLEX LP file */
+      csa->fp = xfopen(fname, "r");
+      if (csa->fp == NULL)
+      {  xprintf("Unable to open `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      /* scan very first token */
+      scan_token(csa);
+      /* parse definition of the objective function */
+      if (!(csa->token == T_MINIMIZE || csa->token == T_MAXIMIZE))
+         error(csa, "`minimize' or `maximize' keyword missing\n");
+      parse_objective(csa);
+      /* parse constraints section */
+      if (csa->token != T_SUBJECT_TO)
+         error(csa, "constraints section missing\n");
+      parse_constraints(csa);
+      /* parse optional bounds section */
+      if (csa->token == T_BOUNDS) parse_bounds(csa);
+      /* parse optional general, integer, and binary sections */
+      while (csa->token == T_GENERAL ||
+             csa->token == T_INTEGER ||
+             csa->token == T_BINARY) parse_integer(csa);
+      /* check for the keyword 'end' */
+      if (csa->token == T_END)
+         scan_token(csa);
+      else if (csa->token == T_EOF)
+         warning(csa, "keyword `end' missing\n");
+      else
+         error(csa, "symbol `%s' in wrong position\n", csa->image);
+      /* nothing must follow the keyword 'end' (except comments) */
+      if (csa->token != T_EOF)
+         error(csa, "extra symbol(s) detected beyond `end'\n");
+      /* set bounds of variables */
+      {  int j, type;
+         double lb, ub;
+         for (j = 1; j <= P->n; j++)
+         {  lb = csa->lb[j];
+            ub = csa->ub[j];
+            if (lb == +DBL_MAX) lb = 0.0;      /* default lb */
+            if (ub == -DBL_MAX) ub = +DBL_MAX; /* default ub */
+            if (lb == -DBL_MAX && ub == +DBL_MAX)
+               type = GLP_FR;
+            else if (ub == +DBL_MAX)
+               type = GLP_LO;
+            else if (lb == -DBL_MAX)
+               type = GLP_UP;
+            else if (lb != ub)
+               type = GLP_DB;
+            else
+               type = GLP_FX;
+            glp_set_col_bnds(csa->P, j, type, lb, ub);
+         }
+      }
+      /* print some statistics */
+      xprintf("%d row%s, %d column%s, %d non-zero%s\n",
+         P->m, P->m == 1 ? "" : "s", P->n, P->n == 1 ? "" : "s",
+         P->nnz, P->nnz == 1 ? "" : "s");
+      if (glp_get_num_int(P) > 0)
+      {  int ni = glp_get_num_int(P);
+         int nb = glp_get_num_bin(P);
+         if (ni == 1)
+         {  if (nb == 0)
+               xprintf("One variable is integer\n");
+            else
+               xprintf("One variable is binary\n");
+         }
+         else
+         {  xprintf("%d integer variables, ", ni);
+            if (nb == 0)
+               xprintf("none");
+            else if (nb == 1)
+               xprintf("one");
+            else if (nb == ni)
+               xprintf("all");
+            else
+               xprintf("%d", nb);
+            xprintf(" of which %s binary\n", nb == 1 ? "is" : "are");
+         }
+      }
+      xprintf("%d lines were read\n", csa->count);
+      /* problem data has been successfully read */
+      glp_delete_index(P);
+      glp_sort_matrix(P);
+      ret = 0;
+done: if (csa->fp != NULL) xfclose(csa->fp);
+      xfree(csa->ind);
+      xfree(csa->val);
+      xfree(csa->flag);
+      xfree(csa->lb);
+      xfree(csa->ub);
+      if (ret != 0) glp_erase_prob(P);
+      return ret;
+}
+
+/***********************************************************************
+*  NAME
+*
+*  glp_write_lp - write problem data in CPLEX LP format
+*
+*  SYNOPSIS
+*
+*  int glp_write_lp(glp_prob *P, const glp_cpxcp *parm, const char
+*     *fname);
+*
+*  DESCRIPTION
+*
+*  The routine glp_write_lp writes problem data in CPLEX LP format to
+*  a text file.
+*
+*  The parameter parm is a pointer to the structure glp_cpxcp, which
+*  specifies control parameters used by the routine. If parm is NULL,
+*  the routine uses default settings.
+*
+*  The character string fname specifies a name of the text file to be
+*  written.
+*
+*  RETURNS
+*
+*  If the operation was successful, the routine glp_write_lp returns
+*  zero. Otherwise, it prints an error message and returns non-zero. */
+
+#define csa csa1
+
+struct csa
+{     /* common storage area */
+      glp_prob *P;
+      /* pointer to problem object */
+      const glp_cpxcp *parm;
+      /* pointer to control parameters */
+};
+
+static int check_name(char *name)
+{     /* check if specified name is valid for CPLEX LP format */
+      if (*name == '.') return 1;
+      if (isdigit((unsigned char)*name)) return 1;
+      for (; *name; name++)
+      {  if (!isalnum((unsigned char)*name) &&
+             strchr(CHAR_SET, (unsigned char)*name) == NULL) return 1;
+      }
+      return 0; /* name is ok */
+}
+
+static void adjust_name(char *name)
+{     /* attempt to adjust specified name to make it valid for CPLEX LP
+         format */
+      for (; *name; name++)
+      {  if (*name == ' ')
+            *name = '_';
+         else if (*name == '-')
+            *name = '~';
+         else if (*name == '[')
+            *name = '(';
+         else if (*name == ']')
+            *name = ')';
+      }
+      return;
+}
+
+static char *row_name(struct csa *csa, int i, char rname[255+1])
+{     /* construct symbolic name of i-th row (constraint) */
+      const char *name;
+      if (i == 0)
+         name = glp_get_obj_name(csa->P);
+      else
+         name = glp_get_row_name(csa->P, i);
+      if (name == NULL) goto fake;
+      strcpy(rname, name);
+      adjust_name(rname);
+      if (check_name(rname)) goto fake;
+      return rname;
+fake: if (i == 0)
+         strcpy(rname, "obj");
+      else
+         sprintf(rname, "r_%d", i);
+      return rname;
+}
+
+static char *col_name(struct csa *csa, int j, char cname[255+1])
+{     /* construct symbolic name of j-th column (variable) */
+      const char *name;
+      name = glp_get_col_name(csa->P, j);
+      if (name == NULL) goto fake;
+      strcpy(cname, name);
+      adjust_name(cname);
+      if (check_name(cname)) goto fake;
+      return cname;
+fake: sprintf(cname, "x_%d", j);
+      return cname;
+}
+
+int glp_write_lp(glp_prob *P, const glp_cpxcp *parm, const char *fname)
+{     /* write problem data in CPLEX LP format */
+      glp_cpxcp _parm;
+      struct csa _csa, *csa = &_csa;
+      XFILE *fp;
+      GLPROW *row;
+      GLPCOL *col;
+      GLPAIJ *aij;
+      int i, j, len, flag, count, ret;
+      char line[1000+1], term[500+1], name[255+1];
+      xprintf("Writing problem data to `%s'...\n", fname);
+      if (parm == NULL)
+         glp_init_cpxcp(&_parm), parm = &_parm;
+      /* check control parameters */
+      check_parm("glp_write_lp", parm);
+      /* initialize common storage area */
+      csa->P = P;
+      csa->parm = parm;
+      /* create output CPLEX LP file */
+      fp = xfopen(fname, "w"), count = 0;
+      if (fp == NULL)
+      {  xprintf("Unable to create `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      /* write problem name */
+      xfprintf(fp, "\\* Problem: %s *\\\n",
+         P->name == NULL ? "Unknown" : P->name), count++;
+      xfprintf(fp, "\n"), count++;
+      /* the problem should contain at least one row and one column */
+      if (!(P->m > 0 && P->n > 0))
+      {  xprintf("Warning: problem has no rows/columns\n");
+         xfprintf(fp, "\\* WARNING: PROBLEM HAS NO ROWS/COLUMNS *\\\n"),
+            count++;
+         xfprintf(fp, "\n"), count++;
+         goto skip;
+      }
+      /* write the objective function definition */
+      if (P->dir == GLP_MIN)
+         xfprintf(fp, "Minimize\n"), count++;
+      else if (P->dir == GLP_MAX)
+         xfprintf(fp, "Maximize\n"), count++;
+      else
+         xassert(P != P);
+      row_name(csa, 0, name);
+      sprintf(line, " %s:", name);
+      len = 0;
+      for (j = 1; j <= P->n; j++)
+      {  col = P->col[j];
+         if (col->coef != 0.0 || col->ptr == NULL)
+         {  len++;
+            col_name(csa, j, name);
+            if (col->coef == 0.0)
+               sprintf(term, " + 0 %s", name); /* empty column */
+            else if (col->coef == +1.0)
+               sprintf(term, " + %s", name);
+            else if (col->coef == -1.0)
+               sprintf(term, " - %s", name);
+            else if (col->coef > 0.0)
+               sprintf(term, " + %.*g %s", DBL_DIG, +col->coef, name);
+            else
+               sprintf(term, " - %.*g %s", DBL_DIG, -col->coef, name);
+            if (strlen(line) + strlen(term) > 72)
+               xfprintf(fp, "%s\n", line), line[0] = '\0', count++;
+            strcat(line, term);
+         }
+      }
+      if (len == 0)
+      {  /* empty objective */
+         sprintf(term, " 0 %s", col_name(csa, 1, name));
+         strcat(line, term);
+      }
+      xfprintf(fp, "%s\n", line), count++;
+      if (P->c0 != 0.0)
+         xfprintf(fp, "\\* constant term = %.*g *\\\n", DBL_DIG, P->c0),
+            count++;
+      xfprintf(fp, "\n"), count++;
+      /* write the constraints section */
+      xfprintf(fp, "Subject To\n"), count++;
+      for (i = 1; i <= P->m; i++)
+      {  row = P->row[i];
+         if (row->type == GLP_FR) continue; /* skip free row */
+         row_name(csa, i, name);
+         sprintf(line, " %s:", name);
+         /* linear form */
+         for (aij = row->ptr; aij != NULL; aij = aij->r_next)
+         {  col_name(csa, aij->col->j, name);
+            if (aij->val == +1.0)
+               sprintf(term, " + %s", name);
+            else if (aij->val == -1.0)
+               sprintf(term, " - %s", name);
+            else if (aij->val > 0.0)
+               sprintf(term, " + %.*g %s", DBL_DIG, +aij->val, name);
+            else
+               sprintf(term, " - %.*g %s", DBL_DIG, -aij->val, name);
+            if (strlen(line) + strlen(term) > 72)
+               xfprintf(fp, "%s\n", line), line[0] = '\0', count++;
+            strcat(line, term);
+         }
+         if (row->type == GLP_DB)
+         {  /* double-bounded (ranged) constraint */
+            sprintf(term, " - ~r_%d", i);
+            if (strlen(line) + strlen(term) > 72)
+               xfprintf(fp, "%s\n", line), line[0] = '\0', count++;
+            strcat(line, term);
+         }
+         else if (row->ptr == NULL)
+         {  /* empty constraint */
+            sprintf(term, " 0 %s", col_name(csa, 1, name));
+            strcat(line, term);
+         }
+         /* right hand-side */
+         if (row->type == GLP_LO)
+            sprintf(term, " >= %.*g", DBL_DIG, row->lb);
+         else if (row->type == GLP_UP)
+            sprintf(term, " <= %.*g", DBL_DIG, row->ub);
+         else if (row->type == GLP_DB || row->type == GLP_FX)
+            sprintf(term, " = %.*g", DBL_DIG, row->lb);
+         else
+            xassert(row != row);
+         if (strlen(line) + strlen(term) > 72)
+            xfprintf(fp, "%s\n", line), line[0] = '\0', count++;
+         strcat(line, term);
+         xfprintf(fp, "%s\n", line), count++;
+      }
+      xfprintf(fp, "\n"), count++;
+      /* write the bounds section */
+      flag = 0;
+      for (i = 1; i <= P->m; i++)
+      {  row = P->row[i];
+         if (row->type != GLP_DB) continue;
+         if (!flag)
+            xfprintf(fp, "Bounds\n"), flag = 1, count++;
+         xfprintf(fp, " 0 <= ~r_%d <= %.*g\n",
+            i, DBL_DIG, row->ub - row->lb), count++;
+      }
+      for (j = 1; j <= P->n; j++)
+      {  col = P->col[j];
+         if (col->type == GLP_LO && col->lb == 0.0) continue;
+         if (!flag)
+            xfprintf(fp, "Bounds\n"), flag = 1, count++;
+         col_name(csa, j, name);
+         if (col->type == GLP_FR)
+            xfprintf(fp, " %s free\n", name), count++;
+         else if (col->type == GLP_LO)
+            xfprintf(fp, " %s >= %.*g\n",
+               name, DBL_DIG, col->lb), count++;
+         else if (col->type == GLP_UP)
+            xfprintf(fp, " -Inf <= %s <= %.*g\n",
+               name, DBL_DIG, col->ub), count++;
+         else if (col->type == GLP_DB)
+            xfprintf(fp, " %.*g <= %s <= %.*g\n",
+               DBL_DIG, col->lb, name, DBL_DIG, col->ub), count++;
+         else if (col->type == GLP_FX)
+            xfprintf(fp, " %s = %.*g\n",
+               name, DBL_DIG, col->lb), count++;
+         else
+            xassert(col != col);
+      }
+      if (flag) xfprintf(fp, "\n"), count++;
+      /* write the integer section */
+      flag = 0;
+      for (j = 1; j <= P->n; j++)
+      {  col = P->col[j];
+         if (col->kind == GLP_CV) continue;
+         xassert(col->kind == GLP_IV);
+         if (!flag)
+            xfprintf(fp, "Generals\n"), flag = 1, count++;
+         xfprintf(fp, " %s\n", col_name(csa, j, name)), count++;
+      }
+      if (flag) xfprintf(fp, "\n"), count++;
+skip: /* write the end keyword */
+      xfprintf(fp, "End\n"), count++;
+      xfflush(fp);
+      if (xferror(fp))
+      {  xprintf("Write error on `%s' - %s\n", fname, xerrmsg());
+         ret = 1;
+         goto done;
+      }
+      /* problem data has been successfully written */
+      xprintf("%d lines were written\n", count);
+      ret = 0;
+done: if (fp != NULL) xfclose(fp);
+      return ret;
+}
+
+/* eof */